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Is the use of supermarket trolleys microbiologically safe? Study of microbiological contamination

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Microbial contamination in shopping trolleys (eighty five) by considering different supermarkets (seven) from three major food companies in Las Palmas de Gran Canaria (Spain) was determined. The two sampled areas were trolley handles and food trolley baskets-child seats. Samples were analyzed by selective and differential microbiological culture media. E. coli four (2.4%) indicative of faecal contamination, Klebsiella pneumoniae twelve (6.5%) and Citrobacter freundii, six (5.1%), which have been isolated from human faecal samples, were isolated from trolleys; Pseudomonas rhodesiae, five (4.25%), and Pseudomonas fluorescens, three (2.55%), which both evidenced environmental contamination. Significant differences among the companies were found for the Enterobacteriaceae and coliforms. Regarding location, these differences (p < 0.003) were observed only for the coliform rates, which were higher in trolleys located outside. The results of this study suggest the implementation of cleaning and disinfection programmes to improve trolley sanitation, and to reduce exposure to both potential pathogenic and transmitting bacterial infections.
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Journal of Applied Animal Research
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Is the use of supermarket trolleys
microbiologically safe? Study of microbiological
Conrado Carrascosa, Esther Sanjuán, Rafael Millán, Sara Martín, Pedro
Saavedra, António Raposo, Cristóbal del Rosario-Quintana & José Raduán
To cite this article: Conrado Carrascosa, Esther Sanjuán, Rafael Millán, Sara Martín, Pedro
Saavedra, António Raposo, Cristóbal del Rosario-Quintana & José Raduán Jaber (2019) Is the use
of supermarket trolleys microbiologically safe? Study of microbiological contamination, Journal of
Applied Animal Research, 47:1, 17-23, DOI: 10.1080/09712119.2018.1555091
To link to this article:
© 2018 The Author(s). Published by Informa
UK Limited, trading as Taylor & Francis
Published online: 12 Dec 2018.
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Is the use of supermarket trolleys microbiologically safe? Study of microbiological
Conrado Carrascosa
, Esther Sanjuán
, Rafael Millán
, Sara Martín
, Pedro Saavedra
, António Raposo
Cristóbal del Rosario-Quintana
and José Raduán Jaber
Department of Animal Pathology and Production, Bromatology and Food Technology, Faculty of Veterinary, Universidad de Las Palmas de Gran
Canaria, Arucas, Spain;
Department of Mathematics, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain;
Department for
Management of Science and Technology Development, Ton Duc Thang University, Ho Chi Minh City, Vietnam;
Faculty of Environment and Labour
Safety, Ton Duc Thang University, Ho Chi Minh City, Vietnam;
Microbiology Service, Complejo Hospitalario Materno-Insular de Gran Canaria, Canary
Health Service, Las Palmas de Gran Canaria, Spain;
Department of Morphology, Faculty of Veterinary, Universidad de Las Palmas de Gran Canaria,
Arucas, Las Palmas, Spain
Microbial contamination in shopping trolleys (eighty ve) by considering dierent supermarkets (seven)
from three major food companies in Las Palmas de Gran Canaria (Spain) was determined.
The two sampled areas were trolley handles and food trolley baskets-child seats. Samples were
analyzed by selective and dierential microbiological culture media.
E. coli four (2.4%) indicative of faecal contamination, Klebsiella pneumoniae twelve (6.5%) and
Citrobacter freundii, six (5.1%), which have been isolated from human faecal samples, were isolated
from trolleys; Pseudomonas rhodesiae,ve (4.25%), and Pseudomonas uorescens, three (2.55%), which
both evidenced environmental contamination. Signicant dierences among the companies were
found for the Enterobacteriaceae and coliforms. Regarding location, these dierences (p< 0.003) were
observed only for the coliform rates, which were higher in trolleys located outside.
The results of this study suggest the implementation of cleaning and disinfection programmes to
improve trolley sanitation, and to reduce exposure to both potential pathogenic and transmitting
bacterial infections.
Received 1 August 2018
Accepted 27 November 2018
Food baskets-child seats;
handles; microbiological
contamination; shopping
trolleys; surfaces
Inanimate objects (fomites) for public use, such as shopping
trolley handles, lift buttons, handrails, etc, which come into
direct contact with usershands, are a source of contamination
of potential pathogenic microorganisms. They come into
contact either directly by surface-to-mouth contact or indirectly
by contaminated ngers and subsequent hand-to-mouth
contact (Gerba and Maxwell 2012; Irshaid et al. 2014). Some
studies have reported frequent exposure to pathogenic Staphy-
lococcus aureus on shopping trolley handles, suggest that it is a
hidden reservoir of this organism, and indicate a shopping
basket/trolley sanitation necessity (Mizumachi et al. 2011).
Shopping trolley contamination may occur from directly hand-
ling raw food products or trolleys contaminated by previous
users (Gerba and Maxwell 2012). Nevertheless, cross-contami-
nation in shopping trolley baskets occurs when disease-
causing microorganisms are transferred from one food type
to surfaces or, as in this case study, when dirty hands transfer
microorganisms to trolley handles or baskets. For example,
raw meat products are often contaminated with foodborne bac-
teria, such as Salmonella and Campylobacter (Bier et al. 2004),
which may be transferred to surfaces. However, the level of bac-
terial contamination on shopping trolleys or shopping baskets
is limiting making health assessment dicult (Mizumachi
et al. 2011). It is believed that up to 80% of common infections
can be spread through coming into contact with contaminated
surfaces (Reynolds et al. 2005). Pathogenic organisms, i.e.
viruses, bacteria and protozoa, may be excreted in large
numbers in biological substances, including blood, mucus,
saliva, faeces and urine (Hall and Douglas 1981; Hall et al.
1981; Feachem et al. 1983; Uhnoo et al. 1990; Weber et al.
1994; Islam et al. 2001). Some microbes are infectious at very
low concentrations and can survive on dierent surfaces like
countertops and telephone handpieces for hours, and even
for weeks (Noskin et al. 1995; Bures et al. 2000; Abad et al. 2001).
Hands are frequently involved in such episodes, and act as
vehicles that spread infections in both the community and hos-
pitals (Pittet et al. 2000). Several studies have been published
about microorganism contagion from contaminated fomites
with pathogens to healthcare workershands in hospitals
(Kramer et al. 2006; Mizumachi et al. 2011). However, a corre-
lation between the burden of contamination on hands and the
likelihood of transmission to patients has not yet been estab-
lished (Bellissimo-Rodrigues et al. 2017). Nonetheless, common
infectious diseases still feature among the top 10 leading
causes of death (Liu et al. 2012; Willmott et al. 2016), and health-
care-associated infections are recognized as a major cause of
preventable death in healthcare settings (Willmott et al. 2016).
© 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
This is an Open A ccess artic le distributed under the terms of the Creative Common s Attributio n License (, which pe rmits unrestricted use,
distributio n, and reprod uction in any medium, prov ided the original work is properly cited .
CONTACT António Raposo
2019, VOL. 47, NO. 1, 1723
Regarding bacterial persistence on surfaces, enterococci
species are able to survive for 24 h with no signicant reduction
in colony counts. Most gram-positive bacteria, such as Entero-
coccus spp. (including VRE), S. aureus (including MRSA) or Strep-
tococcus pyogenes, survive for months on dry surfaces (Kramer
et al. 2006). Many gram-negative species can also survive for
months, such as Acinetobacter spp., Escherichia coli,Klebsiella
spp., Pseudomonas aeruginosa,Serratia marcescens or Shigella
spp. A few others, like Bordetella pertussis,Haemophilus inuen-
zae,Proteus vulgaris or Vibrio cholerae, persist only for days
(Kramer et al. 2006).
Interestingly, vancomycin-resistant enterococci are
capable of prolonged survival on hands, gloves and environ-
mental surfaces, they persist for 60 min on telephone hand-
pieces and for 30 min on the diaphragmatic surface of a
stethoscope (Noskin, et al. 1995). Other authors (Wade et al.
1991) have documented the survival of vancomycin-resistant
E. faecium on hands for up to 30 min and bacteria such as
S. aureus,Acinetobacter,Klebsiella aerogenes,Escherichia coli,
Serratia marcescens,andPseudomonas aeruginosa (Casewell
and Desai 1983). Hence hand washing is considered an essen-
tial aspect of infection control to prevent microorganisms
from being transmitted. A 30-second wash with soap and
water is necessary to completely eradicate bacteria from
hands (Noskin et al. 1995).
The increased availability of shopping trolleys in supermar-
kets, handled by numerous users on a daily basis, and the fact
that trolleys are not routinely disinfected, are a potentially
excellent opportunity for contaminating microorganisms to
be transmitted (Anderson and Palombo 2009). This is particu-
larly true for infants and children under the age of 5 years
with reported 2- to 10-fold higher risk rates than for people
aged 5 years or more (Jones et al. 2006; Ailes et al. 2008).
Riding infants in a shopping trolley next to packaged raw
meat and poultry has been shown to be an important risk
factor for Salmonella spp. and Campylobacter spp. infection,
with attributable risks of 11% and 7%, respectively (Jones
et al. 2006; Fullerton et al. 2007; Patrick et al. 2010) as these
microorganism have been isolated from outer packages of
meat and poultry products at retail outlets (Harrison et al.
2001; Wong et al. 2004; Burgess et al. 2005).
The aim of this study was to determine the microbial con-
tamination and bacterial species on shopping trolley handles
and baskets in dierent supermarkets on the Gran Canaria
Island (Spain). In addition, the statistic relationship between
metal and plastic shopping trolleys microbiological contami-
nation was studied, as was the location of trolleys, either
outside or inside supermarkets.
Material and methods
Sampling was performed in three dierent supermarket compa-
nies of Las Palmas de Gran Canaria (A, B, C), the Canary Islands
(Spain), for 3 months. Eighty-ve shopping trolleys from seven
supermarkets were sampled to determine the microbiological
contamination on trolleys. We collected 85 swabs from trolley
handles and 83 other swabs from the food baskets-child seats
(basket-seat). The latter samples were considered from a
single site (Figure 1).
Sampling the contact surfaces of trolleys
To this end, a maximum 100-cm
area was sampled per swab.
Shopping trolleys were sampled for microbial contamination,
and were subsequently tested for the qualitative analyses of
pathogenics (Gerba and Maxwell 2012). A sterile rayon-tipped
swab (Copan Flock Technologies Srl., Brescia, Italy), moistened
with sterile saline solution (preservative-free), was moved over
the entire surface of trolley handles and a new swap was
used over baskets-seats. Swabs were aseptically transferred to
a tube that contained 10 ml of sterile 0.1% peptone water
(adapted from Salo, et al. 2002), and were delivered 2 h after
being packed on ice to be sent to the Hygiene Laboratory of
Veterinary Faculty of Las Palmas de Gran Canaria University,
where samples were processed before 24 h had elapsed.
The total number of shopping trolleys from each sampled
company was determined by a statistical stratied analysis,
where the following were sampled: 35 (2,700 in all) shopping
trolleys in one supermarket of company A; 30 (2,200 in all) shop-
ping trolleys in three supermarkets of company B; 20 (800 in all)
shopping trolleys in three supermarkets of company C.
Microbiological analysis and identication
Decimal dilutions in peptone water solution (0.85% NaCl with
0.1% peptone; Cultimed, Barcelona, Spain) were used for
microbial enumeration purposes. Tubes were shaken vigor-
ously. Appropriate dilutions were prepared by using sterile
0.1% peptone water and were plated by the pour plate
method on dierent bacteria selection agar (Figure 1). After
incubating the plate, the morphological characteristics of
microorganisms were associated with each growth medium.
Data are reported as colony-forming units (CFU/cm
). All the
counts were taken in duplicate.
Total viable counts (TVCs) and mesophilic bacteria were deter-
mined using Plate Count Agar (PCA Cultimed, 413799), and were
incubated at 31°C for 72 h (Pascual and Calderón 2002; Broekaert
et al. 2011). Enterobacteriaceae were determined using Violet
Red Bile Glucose Agar (VRBG), (Cultimed, 413745, Barcelona
Spain). Incubation was done at 37°C for 24 h. Bacteria were rep-
resented as large colonies with purple haloes, as described by
other authors (Pascual and Calderón 2002).
S. aureus was isolated by Baird Parker+Rabbit Plasma Fibro-
nogen agar (bioMerieux, Marcy ĺEtoile, France; ISO 68882;
ISO, 1999), and was incubated at 37°C for 2448 h. Escherichia
coli was identied by ChromID coli® (bioMerieux; AFNOR,
2014) and was incubated at 37°C for 2448 h.
E. faecalis was determined in kanamycin-esculin-azide broth
(KAA) (Canamicina Esculina Azida, Cultimed, 464695.0922), and
was incubated at 35°C for 48 h following the manufacturers
instructions. Positive growth was considered if the tube
changed to blackish-green. E. faecalis was spread on KAA agar
and incubated at 35°C for 2448 h. Finally, grown colonies
were conrmed as E. faecalis when they were gram-positive
cocci with a negative catalase test, and were able to grow on
bile esculin agar (BEA) incubated at 42°C by esculin hydrolysis
(Greenberg et al. 1992; Dionisio and Borrego 1995).
The microorganisms isolated from VRBG plates were identied
using gram stain, colony counts, morphology, and catalase and
oxidase reactions. Gram-negative bacteria were identied by API
20 E and mass spectrometry in a Bruker Biotyper matrix-assisted
laser desorption ionisation-time of ight mass spectrometry
(MALDITOF MS) system (Bruker Daltonics, Germany) with a
higher score level than 2,200 for species identication.
The Analytical Prole Index (API) 20 E test kit (BioMerieux®,
Marcy ĺEtoile, France) was used following the manufacturers
instructions. Strips were examined after 24 and 48 h. Isolates
were identied according to the API 20 E identication online
instructions (
There are no standards available for fomites surface counts.
However, a general microbial target value of <2.5 CFU/cm
disinfection has been found to be attainable for a range of sur-
faces in food industries (Carrascosa et al. 2012). The preliminary
data obtained in this study showed that the total viable counts
in non-disinfected objects were considerably higher. Even so,
were obtained an average of 753 CFU/cm
, a minimum of
80 CFU/cm
and a maximum of 18,700 CFU/cm
Statistical analysis
The contamination rates for the considered microorganisms
were summarized as frequencies and percentages, and were
compared by the Chi-square (χ
) or the exact Fisher test when-
ever appropriate. Odd ratios by means of 95% condence inter-
vals (95%CI) were used for the comparisons that showed
statistical signicance. Statistical signicance was set at p
< .05. Data were analyzed with the R package, version 3.3.1 (R
Development Core Team 2016).
Figure 1. Flowchart of sampling in the trolleys.
Table 1. Contamination rates of surfaces at dierent supermarket companies (A, B,
C) locations and shopping trolley materials.
Factor Microorganism Level n/ total (%)*
value OR (95%CI)
Company Enterobacteria
A 22/35 (62.9)
.003 1
B 7/30 (23.3)
0.180 (0.061
C 6/20 (30.0)
0.253 (0.078
Coliforms (1) A 14/25 (56.0)
.013 1
B 6/30 (20.0)
0.196 (0.060
C 2/10 (20.0)
0.196 (0.035
A 24/35 (68.6)
.008 1
B 9/30 (30.0)
0.196 (0.068
C 9/18 (50.0)
0.458 (0.143
Coliforms (2) A 15/25 (60.0)
.028 1
B 10/30 (33.3)
0.333 (0.111
C 7/9 (77.8)
2.333 (0.400
(*) Distinct superscripts (
a, b, c
) indicate signicant dierences for p< .05.
Surface sampled: 1, handles; 2, food baskets-child seats.
Eighty-ve shopping trolleys were sampled, and the enteric
bacteria species on handles and baskets-child seats were iso-
lated. Shopping trolley handles were found to be contaminated
by enterobacteria on thirty ve (41.17%) surfaces and on forty
three (50.6%) baskets-child seats. Coliforms were growing on
handles on twenty two (25.9%) trolleys and on thirty nine
(45.9%) baskets-child seats. E. coli was identied only on three
(2.55%) basket-child seats. Neither S. aureus nor E. faecalis was
detected by specic agar medium.
Table 1contains the contamination rates of the sampled sur-
faces of the dierent supermarket companies (A, B, C). This table
also summarizes the contamination rates according to super-
market companies, location and material (Table 2). Company B
showed signicantly lower contamination rates than those
obtained for Company A for enterobacteria on handles (23.3%
vs. 62.9%), coliforms on handles (20% vs. 56%), enterobacteria
on baskets (30% vs. 68.6%) and coliforms on baskets (33.3% vs.
60%). All the results obtained from Companies A, B and C
showed signicant dierences for the coliforms and enterobac-
teria rates on both surfaces. E. coli on baskets was detected only
on one Company A trolley, whereas S. aureus and E. faecalis were
not detected on any analyzed trolley from companies A, B, C.
For the relationship of the location (outside or inside) of
shopping trolleys in supermarkets and their contamination,
we found signicant dierences, but only for the coliforms
rates (56.0% vs. 20.0%, p= .003) on handle surfaces. Contami-
nation was higher outside than it was inside (Table 2). Likewise,
the comparison made of the plastic and metal material used to
manufacture shopping trolleys showed no signicant
dierences (Table 2). The highest contamination rates on
handles and on basket-child seats were on plastic material,
except for coliforms contamination on handles, which was
higher for metal trolleys (Table 2).
In addition, E. coli and other potential pathogenic bacteria
were also isolated from both surfaces, but showed dierent
rates. The isolations of the bacteria that belonged to the Enter-
obactericeae family were particularly interesting, including Kleb-
siella pneumoniae isolated from 11 (6.5%) shopping trolleys,and
Citrobacter freundii isolated from 6 (5.1%), which may be found
in human faeces. Pseudomonas rhodesiae and P.uorescens
were isolated from ve (4.25%) and three (2.55%) shopping trol-
leys, respectively, and these bacteria evidenced environmental
contamination. Table 3shows other bacteria of special interest
that were isolated from trolleys.
Microbiological counts in the analyzed shopping trolleys from
dierent supermarkets showed a high contamination rate on
both sampled surfaces, which was slightly higher on baskets-
child seats. Most studies about fomites contamination have
been undertaken on hospital equipment surfaces (Kramer
et al. 2006; Bellissimo-Rodrigues et al. 2017), but very few
studies have determined contaminated shopping trolleys (Al-
Ghamdi et al. 2011; Ashgar and El-Said 2012; Gerba and
Maxwell 2012; Irshaid et al. 2014), which indicates that consu-
mers are exposed to enteric bacteria from grocery shopping
trolleys on a regular basis. In our study, total bacterial levels
were far higher than those found in public restrooms and
other public places (airports, bus stations, public bathroom,
shopping malls, etc.) reported by other authors (Gerba and
Maxwell 2012). Those studies had sampled dierent surfaces
with the same swab (handles-child seat) and obtained a
single result for all the surfaces.
In the present study, we found up to 45.9% of coliforms and
2.45% of E. coli, whereas Gerba and Maxwell (2012) found
higher rates (72% and 21.17%, respectively). Similar results
were shown by Reynolds et al. (2005) and Al-Ghamdi et al.
(2011) and who determined 20% of coliform and 7% of faecal
coliform contamination, respectively. Regarding contamination
sources, Reynolds et al. (2005) found no relationship to link bio-
chemical markers, protein and bacterial contamination on
public surfaces, including shopping trolley handles. While the
presence of biochemical markers and protein provides
Table 2. Contamination rates of surfaces at dierent locations and shopping
trolley materials.
Factor Microorganism Level n/ total (%)*
value OR (95%CI)
Location Enterobacteria
Inside 13/40 (32.5) .125 1
Outside 22/45 (48.9) 1.987 (0.822
Coliforms (1) Inside 8/40 (20.0) .003 1
Outside 14/25 (56.0) 5.091 (1.684
Inside 16/39 (41.0) .100 1
Outside 26/44 (59.1) 2.076 (0.864
Coliforms (2) Inside 17/39 (43.6) .200 1
Outside 15/25 (60.0) 1.941 (0.700
Material Enterobacteria
Metal 7/24 (29.2) .158 1
Plastic 28/61 (45.9) 2.061 (0.747
Coliforms (1) Metal 6/14 (42.9) .527 1
Plastic 16/51 (31.4) 0.610 (0.181
Metal 9/22 (40.9) .289 1
Plastic 33/61 (54.1) 1.702 (0.634
Coliforms (2) Metal 6/13 (46.2) .756 1
Plastic 26/51 (51.0) 1.213 (0.358
(*) Distinct superscripts (
a, b, c
) indicate signicant dierences for p< .05.
Surface sampled: 1, handles; 2, food baskets-child seats.
Table 3. Relation of the bacteria of special interest isolated from trolleys identied
Isolated Bacteria n/ total (%)
E. coli 4 (2.4)
Klebsiela pneumoniae 11 (9.3)
Citrobacter freundi 9 (5.3)
Pseudomonas rhodesiae 4 (2.3)
Pseudomonas uorescens 3 (1.7)
Enterococcus faecalis 3 (1.7)
Staphylococcus haemolyticus 3 (1,7)
Streptococcus gallolyticus 3 (1.7)
Morganella morganii 2 (1.2)
Proteus mirabilis 2 (1.2)
Enterobacter asburiae 2 (1.2)
information on the relative hygiene of various environments,
very little is known about their correlation with infectious
microbes (Reynolds et al. 2005). Nonetheless, other authors
have described longer microbial persistence with higher inocu-
lum in the presence of protein (Neely 2000), serum (Elmos 1977;
Hirai 1991) or without dust (Wagenvoort and Penders 1997), but
these studies were undertaken on fomites in hospitals.
Thus persistence of bacteria on surfaces can vary subject to
intrinsic factors from microorganisms: gram-negative bacteria
have been described to persist longer than gram-positive bac-
teria (Dickgiesser 1978; Hirai 1991). The latter are transmitted
readily from environmental surfaces, followed by viruses and
gram-negative bacteria (Rusin et al. 2002). Humid conditions
and low temperatures, e.g. 4°C or 6°C, also improve the persist-
ence of most bacteria types, such as Listeria monocytogenes
(Helke and Wong 1994), Salmonella typhimurium (Helke and
Wong 1994), Methicillin-resistant Staphylococcus aureus
(MRSA) (Noyce et al. 2006), or Escherichia coli (Wilks et al.
2005; Williams et al. 2005). These risks can be minimized by
applying a shopping trolley cleaning and disinfection pro-
gramme using antimicrobial agents, according to the data
reported in this eld (Rutala and Weber 2001; Engelhart et al.
2002), and by devising ecient planning to rotate the periodical
cleaning of all supermarket trolleys (between 800 and 2,700
trolleys per supermarket).
The potential pathological microorganism ndings on the
shopping trolleys included in this study agree with those
reported by other authors (Reynolds et al. 2005; Al-Ghamdi
et al. 2011; Ashgar and El-Said 2012; Gerba and Maxwell
2012). Our results revealed the importance of cleaning and dis-
infecting shopping trolleys to avoid the presence of K. pneumo-
nia, which is an opportunistic pathogen responsible for a high
proportion (48%) of nosocomial infections (Podschun and
Ullmann 1998).
In addition, many studies have clearly shown that E. coli is
the only coliform that is an undoubted inhabitant of the gastro-
intestinal tract. While Klebsiella spp., Citrobacter freundii and
Enterobacter have been isolated from human faecal samples,
they are in small numbers when present (Edberg et al. 2000).
However, these opportunistic pathogens isolated herein such
as C. freundii, which can cause systemic infections (Kim et al.
2003; Pereira et al. 2010; Chen et al. 2011). Moreover, C. freundii
has been used to control good healthy measures, like periodical
cleaning of tools and abattoir surfaces (Milhem et al. 2016).
P. uorescens has been reported to cause infections like blood
transfusion-related septicaemia (Khabbaz et al. 1984). Thus,
results of epidemiological studies have shown that a risk of
infection from common enteric bacteria is related to the
placing of small children in shopping carts (Fullerton et al.
2007; Patrick et al. 2010) and it increases the risk of coming
into contact with a disease-causing organism.
When comparing plastic or metal shopping trolleys, plastic
ones showed higher contamination, but dierences were not
signicant. Nevertheless, larger sample sizes should be con-
sidered to obtain signicant dierences (p< 0.05). the tested
material types gave no consistent results for nosocomial persist-
ent pathogenics on inanimate surfaces. Although some
researchers have reported that this type of material has no
inuence on persistence (Bale et al. 1993; Wendt et al. 1997),
other authors have described longer persistence on plastic
(Neely and Maley 2000). This topic can be clearly observed in
food industries, where the ability of many bacteria to adhere
to surfaces and to form biolms has major implications. Proper-
ties like surface roughness, cleanability, disinfectability, wett-
ability and vulnerability to wear inuence the ability of cells
to adhere to a particular surface, and thus determine the hygie-
nic status of materials (Van Houdt and Michiels 2010). Other
authors (Bellissimo-Rodrigues et al. 2017) have described a
direct relationship between the bacterial load present on
hands and the risk of cross transmission following a single
hand-to-hand contact. Under the described experimental con-
ditions, at least 1 log
CFU of E. coli must be present on
hands for it to be potentially transmitted to another person.
This threshold may be useful to develop an evidence-based
safe handsmicrobiological concept that can be applied in
the healthcare setting, and in the general community to
prevent infections and antimicrobial resistance from spreading
(Bellissimo-Rodrigues et al. 2017).
The obtained results suggest the need to establish adequate
cleaning and disinfection programmes for shopping trolleys in
order to avoid exposing shopping trolley users to infections.
The most eective measure could be the use of an alkaline deter-
gent and quaternary ammonium as a disinfectant, washing the
shopping trolleys once a month and doing a proper rotation of
them. The material (metal or plastic) and location (outside or
inside) of the shopping trolleys in the supermarkets should be
taken into consideration during the preparation of the cleaning
and disinfection plan, to reduce microbial contamination more
eectively. As additional measures, some studies have proposed
using disinfecting wipes or disposable plastic barriers for
handles. In the future, we hope to compare our contamination
results and potential pathogenic rates with other studies done
on supermarket trolleys, which have established a cleaning
and disinfection programme to assess their ecacy and to
nally answer the age-old debate about the relevance of
environmental contamination.
.Determination of microbial contamination in shopping trol-
leys located in Las Palmas.
.Isolation and identication of several pathogenic bacteria.
.Environmental contamination was evidenced.
.High microbiological contamination of supermarket trolleys
was evidenced.
Disclosure statement
No potential conict of interest was reported by the authors.
António Raposo
Abad FX, Villena C, Guix S, Caballero S, Pinto RM, Bosch A. 2001. Potential
role of fomites in the vehicular transmission of human astroviruses.
Appl Environ Microbiol. 67:39043907.
Ailes EL, Demma S, Hurd J, Hatch TF, Jones D, Vugia A, Cronquist M, Tobin-
DAngelo K, Larson E, Laine K, et al. 2008. Continued decline in the inci-
dence of Campylobacter infections, FoodNet, 19962006. Foodborne
Pathog Dis. 5:329337.
Al-Ghamdi AK, Ashshi SAA, Faidah H, Shukri H, Jiman-Fatani AA. 2011.
Bacterial contamination of computer keyboards and mice, elevator
buttons and shopping carts. Afr J Microbiol Res. 5(23):39984003.
Anderson G, Palombo EA. 2009. Microbial contamination of computer key-
boards in a university setting. Am J Infect Control. 37(6):507509.
Ashgar SS, El-Said HM. 2012. Pathogenic bacteria associated with dierent
public environmental sites in Mecca city. Open J Med Microbiol. 2
Bale MJ, Bennett PM, Beringer JE, Hinton M. 1993. The survival of bacteria
exposed to desiccation on surfaces associated with farm buildings. J
Appl Bacteriol. 75:519528.
Bellissimo-Rodrigues F, Pires D, Soule H, Gayet-Ageron A, Pittet D. 2017.
Assessing the likelihood of hand-to-hand cross-transmission of bac-
teria: an experimental study. Infect Control Hosp Epidemiol. 38
Bier RC, Pillai SD, Phillips TD, Ziprin RL. 2004. Preharvest and postharvest
food safety. Ames, IA: Blackwell Publishing.
Broekaert K, Heyndrickx M, Herman L, Devlieghere F, Vlaemynck G. 2011.
Seafood quality analysis: molecular identication of dominant microbiota
after ice storage on several general growth media. Food Microbiol. 28
Bures S, Fishbain JT, Uyehara CFT, Parker JM, Berg BW. 2000. Computer key-
boards and faucet handles as reservoirs of nosocomial pathogens in the
intensive care unit. Am J Infect Control. 28:465471.
Burgess F, Little C, Allen G, Williamson K, Mitchell RT. 2005. Prevalence of
Campylobacter, Salmonella, and Escherichia coli on the external packaging
of raw meat. J Food Prot. 68:469475.
Carrascosa C, Saavedra P, Millán R, Jaber JR, Pérez E, Grau R, Raposo A,
Mauricio C, Sanjuán E. 2012. Monitoring of cleanliness and disinfection
in dairies: comparison of traditional microbiological and ATP biolumines-
cence methods. Food Control. 28(2):368373.
Casewell MW, Desai N. 1983. Survival of multiply-resistant Klebsiella aero-
genes and other gram-negative bacilli on nger-tips. J Hosp Infect. 4
Chen S, Hu F, Liu Y, Zhu D, Wang H, Zhang Y. 2011. Detection and spread of
carbapenem-resistant Citrobacter freundii in a teaching hospital in China.
Am J Infect Control. 39(9):e55e60.
Dickgiesser N. 1978. Untersuchungen über das Verhalten grampositiver und
gramnegativer Bakterien in trockenem und feuchtem Milieu. Zbl Bakt
Hyg I. Abt. 167:4862.
Dionisio LPC, Borrego JJ. 1995. Evaluation of media for the enumeration of
faecal streptococci from natural water samples. J Microbiol Methods.
Edberg SCL, Rice EW, Karlin RJ, Allen MJ. 2000. Escherichia coli: the best bio-
logical drinking water indicator for public health protection. J Appl
Microbiol. 88(S1):106S116S.
Elmos T. 1977. Survival of Neisseria gonorrhoeae on surfaces. Acta Derm
Venereol. 57:177180.
Engelhart S, Krizek L, Glasmacher A, Fischnaller E, Marklein G, Exner M. 2002.
Pseudomonas aeruginosa outbreak in a haematologyoncology unit
associated with contaminated surface cleaning equipment. J Hosp
Infect. 52:9398.
Feachem RG, Bradley DJ, Garelick H, Mara DD. 1983. Sanitation and disease.
New York: Wiley.
Fullerton KE, Ingram LA, Jones TF, Anderson BJ, McCarthy PV, Hurd S,
Shiferaw B, Vugia D, Haubert N, Hayes T, et al. 2007. Sporadic
Campylobacter infection in infants: a population-based case control
study. Pediatr Infect Dis J. 26:1924.
Gerba CP, Maxwell S. 2012. Bacterial contamination of shopping carts and
approaches to control. Food Prot Trends. 32(12):747749.
Greenberg AE, Clesceri LS, Eaton AD, editors. 1992. Standard methods for
the examination of water and wastewater, 18th ed. Washington, DC:
American Public Health Association.
Hall CB, Douglas RG. 1981. Modes of transmission of respiratory syncytial
virus. J Pediatr. 99:100103.
Hall CB, Douglas RG, Schnabel KC, Geiman JM. 1981. Infectivity of respiratory
syncytial virus by various routes of inoculation. Infect Immun. 33:779
Harrison WA, Grith CJ, Tennant D, Peters AC. 2001. Incidence of
Campylobacter and Salmonella isolated from retail chicken and associ-
ated packaging in South Wales. Lett Appl Microbiol. 33:450454.
Helke DM, Wong ACL. 1994. Survival and growth characteristics of Listeria
monocytogenes and Salmonella typhimurium on stainless steel and
Buna-N rubber. J Food Prot. 57:963968.
Hirai Y. 1991. Survival of bacteria under dry conditions; from a viewpoint of
nosocomial infection. J Hosp Infect. 19:191200.
Irshaid FI, Jacob JH, Khwaldh AS. 2014. Contamination of the handles and
bases of shopping carts by pathogenic and multi-drug resistant bacteria.
ESJ. 10(27):154169.
Islam MS, Hossain MA, Khan SI, Khan MN, Sack RB, Albert MJ, Huq A, Colwell
RR. 2001. Survival of Shigella dysenteriae type 1 on fomites. J Health Popul
Nutr. 19:177182.
Jones TF, Ingram LA, Fullerton KE, Marcus R, Anderson BJ, McCarthy PV,
Vugia D, Shiferaw B, Haubert N, Wedel S, Angulo FJ. 2006. A case-
control study of the epidemiology of sporadic Salmonella infections in
infants. Pediatrics. 118:23802387.
Khabbaz RF, Arnow PM, Highsmith AK, Herwaldt LA, Chou T, Jarvis WR,
Lerche NW, Allen JR. 1984.Pseudomonas uorescens bacteremia from
blood transfusion. Am J Med. 76(1):6268.
Kim BN, Woo JH, Ryu J, Kim YS. 2003. Resistance to extended-spectrum
cephalosporins and mortality in patients with Citrobacter freundii bacter-
emia. Infection. 31:202207.
Kramer A, Schwebke I, Kampf G. 2006. How long do nosocomial pathogens
persist on inanimate surfaces? A systematic review. BMC Infect Dis. 6
Liu L, Johnson HL, Cousens S, Perin J, Scott S, Lawn JE, Rudan I, Campbell H,
Cibulskis R, Li M, et al. 2012. Child health epidemiology reference group
of WHO and UNICEF. Global, regional, and national causes of child mor-
tality: an updated systematic analysis for 2010 with time trends since
2000. Lancet. 379:21512161.
Milhem H, Azizieh A, Younes AA. 2016. Prevalence of Escherichia coli and
Citrobacter freundii in raw beef from major abattoirs located in damas-
cus and countryside, Syria. Int J ChemTech Res. 9:290296.
Mizumachi E, Kato F, Hisatsune J, Tsuruda K, Uehara Y, Seo Y, Sugai M. 2011.
Clonal distribution of enterotoxigenic Staphylococcus aureus on handles
of handheld shopping baskets in supermarkets. J Appl Microbiol.
Neely AN. 2000. A survey of gram-negative bacteria survival on hospital
fabrics and plastics. J Burn Care Rehabil. 21:523527.
Neely AN, Maley MP. 2000. Survival of enterococci and staphylococci on hos-
pital fabrics and plastic. J Clin Microbiol. 38(2):724726.
Noskin GA, Stosor V, Cooper I, Peterson LR. 1995. Recovery of vancomycin-
resistant enterococci on ngertips and environmental surfaces. Infect
Control Hosp Epidemiol. 16(10):577581.
Noyce JO, Michels H, Keevil CW. 2006. Potential use of copper surfaces to
reduce survival of epidemic meticillin-resistant Staphylococcus aureus in
the healthcare environment. J Hosp Infect. 63:289297.
Pascual MR, Calderón V. 2002. Microbiologia alimentaria: Metodología
analítica para alimentos y bebidas, 2nd ed. Madrid, Spain: Edt. Díaz de
Patrick ME, Mahon BE, Zansky SM, Hurd S, Scallan E. 2010. Riding in shop-
ping carts and exposure to raw meat and poultry products: prevalence
of, and factors associated with, this risk factor for Salmonella and
Campylobacter infection in children younger than 3 years. J Food Prot.
Pereira AL, Silva TN, Gomes ACCM, Araújo ACG, Giugliano LG. 2010. Diarrhea-
associated biolm formed by enteroaggregative Escherichia coli and
aggregative Citrobacter freundii: a consortium mediated by putative F
pili. BMC Microbiol. 10:5774.
Pittet D, Hugonnet S, Harbarth S, Mourouga P, Sauvan V, Touveneau S,
Perneger TV. 2000.Eectiveness of a hospital-wide programme to
improve compliance with hand hygiene. Infection control programme.
Lancet. 356:13071312.
Podschun R, Ullmann U. 1998.Klebsiella spp. as nosocomial pathogens: epi-
demiology, taxonomy, typing methods, and pathogenicity factors. Clin
Microbiol Rev. 11:589603.
R Development Core Team. 2016. R: A language and environment for stat-
istical computing. Vienna: R Foundation for Statistical Computing.
Reynolds KA, Watt PM, Boone SA, Gerba CP. 2005. Occurrence of bacteria
and biochemical markers on public surfaces. Int J Environ Health Res.
Rusin P, Maxwell S, Gerba C. 2002. Comparative surface-to-hand and
ngertip-to-mouth transfer eciency of gram-positive bacteria, gram-
negative bacteria, and phage. J Appl Microbiol. 93(4):585592.
Rutala WA, Weber DJ. 2001. Surface disinfection: should we do it? J Hosp
Infect. 48:S64S68.
Salo S, Alanko T, Sjöberg AM, Wirtanen G. 2002. Validation of the Hygicult® E
dipslides method in surface hygiene control: a Nordic collaborative study.
J AOAC Int. 85(2):388394.
Uhnoo I, Svenson L, Wadell G. 1990. Enteric adenoviruses. In: Farthing MJG,
editor. Baillières clinical gastroenterology. London: Baillière Tindall, 4(3);
p. 627642.
Van Houdt R, Michiels CW. 2010. Biolm formation and the food industry, a
focus on the bacterial outer surface. J Appl Microbiol. 109(4):11171131.
Wade JJ, Desai N, Casewell MW. 1991. Hygienic hand disinfection for the
removal of epidemic vancomycin-resistant Enterococcus faecium and
gentamicin-resistant Enterobacter cloacae. J Hosp Infect. 18(3):211
Wagenvoort JHT, Penders RJR. 1997. Long-term in-vitro survival of an epi-
demic MRSA phage-group III-29 strain. J Hosp Infect. 35:322325.
Weber R, Bryan R, Schwartz D, Owen R. 1994. Human microsporidial infec-
tions. Clin Microbiol Rev. 7(4):426461.
Wendt C, Dietze B, Dietz E, Rüden H. 1997. Survival of Acinetobacter bau-
mannii on dry surfaces. J Clin Microbiol. 35:13941397.
Wilks SA, Michels H, Keevil CW. 2005. The survival of Escherichia coli O157 on
a range of metal surfaces. Int J Food Microbiol. 105:445454.
Williams AP, Avery LM, Killham K, Jones DL. 2005. Persistence of Escherichia
coli O157 on farm surfaces under dierent environmental conditions. J
Appl Microbiol. 98:10751083.
Willmott M, Nicholson A, Busse H, MacArthur GJ, Brookes S, Campbell R.
2016.Eectiveness of hand hygiene interventions in reducing illness
absence among children in educational settings: a systematic review
and meta-analysis. Arch Dis Childhood. 101:4250.
Wong TL, Whyte RJ, Cornelius AJ, Hudson JA. 2004. Enumeration of
Campylobacter and Salmonella on chicken packs. Br Food J. 106:651662.
... Unfortunately, only a limited number of such cfu/cm 2 values are available for health care units (Table 1) (Shams et al. 2016;Souli et al. 2017;Casini et al. 2018;Costa et al. 2019;Eichner et al. 2020). The presence and transmission of MoV play a role also in other fields like food processing (Gogliettino et al. 2019;Ma et al. 2019;Xing et al. 2019) and highly frequented public areas, in which many people alternately touch surfaces like door handles (Shams et al. 2016;Thapaliya et al. 2017), mobile phones (Kirkby and Biggs 2016;Katsuse Kanayama et al. 2017), banknotes (Vriesekoop et al. 2010;Angelakis et al. 2014), and other items (Table 1) (Ijaz et al. 2016;Carrascosa et al. 2019;Qi et al. 2019;Zou et al. 2019). ...
... Critical surfaces are surfaces, which are frequently touched by patients and/or staff especially patient-near surfaces as well as clinical equipment like electrocardiogram machines, blood pressure cuffs, or stethoscopes (Hong et al. 2009). Outside health care settings, inanimate surfaces may play a role for MoV transmission like frequently touched surfaces in any public areas (Vriesekoop et al. 2010;Sirsat et al. 2013;Patel et al. 2018;Carrascosa et al. 2019). ...
Recent reports provide evidence that contaminated healthcare environments represent major sources for the acquisition and transmission of pathogens. Antimicrobial coatings (AMC) may permanently and autonomously reduce the contamination of such environmental surfaces complementing standard hygiene procedures. This review provides an overview of the current status of AMC and the demands to enable a rational application of AMC in health care settings. Firstly, a suitable laboratory test norm is required that adequately quantifies the efficacy of AMC. In particular, the frequently used wet testing (e.g. ISO 22196) must be replaced by testing under realistic, dry surface conditions. Secondly, field studies should be mandatory to provide evidence for antimicrobial efficacy under real-life conditions. The antimicrobial efficacy should be correlated to the rate of nosocomial transmission at least. Thirdly, the respective AMC technology should not add additional bacterial resistance development induced by the biocidal agents and co- or cross-resistance with antibiotic substances. Lastly, the biocidal substances used in AMC should be safe for humans and the environment. These measures should help to achieve a broader acceptance for AMC in healthcare settings and beyond. Technologies like the photodynamic approach already fulfil most of these AMC requirements.
... These isolates were characterized as non-MDRs but had different biofilm formation capacities and belonged to different STs as well. Many studies have investigated the contamination of shopping cart handles with pathogenic bacteria and coliforms (Al-Ghamdi et al., 2011;Mizumachi et al., 2011;Gerba & Maxwell, 2012;Fawzi I. Fawzi et al., 2014;Carrascosa et al., 2019;Calle et al., 2020;, but none of them described the isolation of A. baumannii from these surfaces. These handles are considered as high touch surfaces, and thus contribute to the spread of pathogens among shoppers and in the community. ...
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Aim: Acinetobacter baumannii is a well-known nosocomial pathogen that has been isolated from different clinical sources. This pathogen also causes community-acquired infections, with mortality rates as high as 64%. The exact natural habitat of this bacterium is still unknown. In this study, we investigated the prevalence of A. baumannii in diverse soil and high-touch surface samples collected from a university campus, malls, parks, hypermarkets and produce markets, roundabout playground slides, and bank ATMs. Methods and results: All obtained isolates were characterized for their antibiotic susceptibility, biofilm formation capacities, and were typed by multi-locus sequence analysis. A total of 63 A. baumannii isolates were recovered, along with 46 A. pittii and 8 A. nosocomialis isolates. Sequence typing revealed that 25 A. baumannii isolates are novel strains. Toilets and sink washing basins were the most contaminated surfaces, accounting for almost 50% of the recovered isolates. A number of A. baumannii (n=10), A. pittii (n=19) and A. nosocomialis (n=5) isolates were recovered from handles of shopping carts and baskets. The majority of isolates were strong biofilm formers and 4 exhibited a multi-drug resistant (MDR) phenotype. Conclusions: Our study is the first to highlight community restrooms and shopping carts as potential reservoirs for pathogenic Acinetobacter species. Further studies are required to identify the reasons associated with the occurrence of A. baumannii inside restrooms. Proper disinfection of community environmental surfaces and spreading awareness about the importance of hand hygiene may prevent the dissemination of pathogenic bacteria within the community. Significance and impact of study: Serious gaps remain in our knowledge of how A. baumannii spreads to cause disease. This study will advance our understanding of how this pathogen spreads between healthcare and community environments. In addition, our findings will help healthcare decision makers implement better measures to control and limit further transmission of A. baumannii.
... The lack of association in our study may reflect that this practice is not common in Hong Kong. Shopping carts are frequently handled by numerous users and not routinely disinfected in supermarkets 37 and have high microbiological loads on handles and basket-child seats. Children may come into direct contact with Salmonella through touching contaminated packaging of raw chicken meat contaminated with Salmonella 38 39 suggesting that parents should prevent their child touching raw products and use hand sanitizer to wipe shopping carts. ...
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Objective To explore risk factors associated with non-typhoidal Salmonella gastroenteritis in young children in Hong Kong. Design A case–control study. Setting Paediatrics wards at three public hospitals in Hong Kong. Participants Cases were children aged above 30 days to below 5 years hospitalised for gastroenteritis at three public hospitals in Hong Kong with culture confirmed non-typhoidal Salmonella infection. Controls were age-matched (±2 months) children admitted for a reason other than gastroenteritis. Main outcomes measures A face-to-face interview by using standardised questionnaire on exposures 3 days prior to illness. Adjusted OR (aORs) and 95% CIs were calculated using multivariable logistic regression. Results A total of 102 cases and 204 age-matched controls were included in the analysis. Multivariable logistic regression revealed that having food purchased from places other than a supermarket, that is, from wet market/restaurant/farm (aOR, 2.64; 95% CI, 1.03 to 6.77; p=0.044) was a significant risk factor for non-typhoidal Salmonella infection. Having a household member with gastroenteritis symptoms (aOR, 2.03; 95% CI, 0.94 to 4.39; p=0.072) was of borderline significance and playing at a children’s indoor playroom was a protective factor (aOR, 0.28; 95% CI, 0.09 to 0.85; p=0.024). Conclusions Consumption of food purchased from places other than a supermarket was the identified determinant factor for non-typhoidal Salmonella gastroenteritis in Hong Kong. Parents/caregivers should be alerted to this risk when choosing foods for their young children. The protective effect of playing in an indoor playroom could be confounded by socioeconomic factors and further investigation is required to better understand its potential implication. There was some support for person-to-person transmission and good family hygiene needs to be emphasised.
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Mathematical modelling is an important public health tool for aiding understanding the spread of respiratory infectious diseases, such as influenza or COVID-19, and for quantifying the effects of behavioural interventions. However, such models rarely explicitly appeals to theories of human behaviour to justify model assumptions. Here we propose a novel mathematical model of disease transmission via fomites (luggage trays) at airport security screening during an outbreak. Our model incorporates the self-protective behaviour of using hand sanitiser gel in line with the extended parallel processing model (EPPM) of behaviour. We find that changing model assumptions of human behaviour in line with the EPPM gives qualitatively different results on the optimal placement of hand sanitiser gels within an airport compared to the model with naive behavioural assumptions. Specifically, that it is preferable to place hand sanitiser gels after luggage screening in most scenarios, however in situations where individuals perceive high threat and low efficacy this strategy may need to be reviewed. This model demonstrates how existing behavioural theories can be incorporated into mathematical models of infectious disease.
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A collaborative study with Enterobacteriaceae was conducted to validate Hygicult® E dipslides by comparison with violet red bile glucose agar (VRBGA) contact plates and swabbing, using stainless steel surfaces artificially contaminated with microbes at various levels. Twelve laboratories participated in the validation procedure. The total number of collaborative samples was 108. The microbial level in each sample was assessed in triplicate by using the 3 above-mentioned methods. No Enterobacteriaceae were used at the low inoculation level. At the middle inoculation level, the percentages detached from the test surfaces were 16.6 with the Hygicult E method, 15.3 with the contact plate method, and 14.6 with swabbing; at the high innoculation level, the percentages were 14.5, 15.8, and 9.8, respectively. The percentage of acceptable results after the removal of outliers was 97.2. Repeatability relative standard deviations ranged from 33.4 to 44.9%; reproducibility relative standard deviations ranged from 45.2 to 77.1%. The Hygicult E dipslide, VRBGA contact plate, and swabbing methods gave similar results at all 3 microbial levels tested: <1.0 colony-forming units (CFU)/cm2 at the low level, 1.2–1.3 CFU/cm2 at the middle level (theoretical yield 8.0 CFU/cm2), and 1.2–2.0 CFU/cm2 at the high level (theoretical yield 12.5 CFU/cm2).
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BACKGROUND Although the hands of healthcare workers (HCWs) are implicated in most episodes of healthcare-associated infections, the correlation between hand contamination and the likelihood of cross-transmission remains unknown. METHODS We conducted a laboratory-based study involving pairs of HCWs. The hands of a HCW (transmitter) were contaminated with Escherichia coli ATCC 10536 before holding hands with another HCW (host) for 1 minute. Meanwhile, the unheld hand of the transmitter was sampled. Afterward, the host’s held hand was also sampled. Each experiment consisted of 4 trials with increasing concentrations of E. coli (10 ³ –10 ⁶ colony-forming units [cfu]/mL). The primary outcome was the likelihood of transmission of at least 1 cfu from transmitter to host. We used a mixed logistic regression model with a random effect on the subject to assess the association between transmission and bacterial count on the transmitter’s hands. RESULTS In total, 6 HCWs performed 30 experiments and 120 trials. The bacterial counts recovered from host hands were directly associated with the bacterial counts on transmitter hands ( P <.001). The probability of cross-transmission was 8.22 higher (95% confidence interval [CI], 0.98–68.8) when transmitter hand bacterial count was >1 and ≤3 log 10 cfu compared to ≤1 log 10 . When transmitter contamination was <1 log 10 cfu, no cross-transmission was detected. CONCLUSION There is a direct relationship between the bacterial burden on HCWs hands and the likelihood of cross-transmission. Under the described conditions, at least 1 log 10 cfu must be present on HCW hands to be potentially transmitted. Further studies are needed at the low contamination range. Infect Control Hosp Epidemiol 2017;38:553–558
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Escherichia coli O157:H7 is a serious pathogen causing haemorrhagic colitis. It has been responsible for several large-scale outbreaks in recent years. E. coli O157:H7 is able to survive in a range of environments, under various conditions. The risk of infection from contaminated surfaces is recognised, especially due to the low infectious dose required. In this study, a high concentration (107 cells) of E. coli O157 was placed onto different metals and survival time measured. Results showed E. coli O157 to survive for over 28 days at both refrigeration and room temperatures on stainless steel. Copper, in contrast, has strong antibacterial properties (no bacteria can be recovered after only 90 min exposure at 20 °C, increasing to 270 min at 4 °C) but its poor corrosion resistance and durability make it unsuitable for use as a surface material. Other copper-containing alloys, such as copper nickels and copper silvers, have improved durability and anticorrosion properties and greatly reduce bacterial survival times at these two temperatures (after 120 min at 20 °C and 360 min at 4 °C, no E. coli could be detected on a copper nickel with a 73% copper content). Use of a surface material with antibacterial properties could aid in preventing cross-contamination events in food processing and domestic environments, if standard hygiene measures fail.
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Objective To undertake a systematic review and meta-analysis to establish the effectiveness of handwashing in reducing absence and/or the spread of respiratory tract (RT) and/or gastrointestinal (GI) infection among school-aged children and/or staff in educational settings. Design Randomised-controlled trials (RCTs). Setting Schools and other settings with a formal educational component in any country. Patients Children aged 3–11 years, and/or staff working with them. Intervention Interventions with a hand hygiene component. Main outcome measures Incidence of RT or GI infections or symptoms related to such infections; absenteeism; laboratory results of RT and/or GI infections. Results Eighteen cluster RCTs were identified; 13 school-based, 5 in child day care facilities or preschools. Studies were heterogeneous and had significant quality issues including small numbers of clusters and participants and inadequate randomisation. Individual study results suggest interventions may reduce children's absence, RT infection incidence and symptoms, and laboratory confirmed influenza-like illness. Evidence of impact on GI infection or symptoms was equivocal. Conclusions Studies are generally not well executed or reported. Despite updating existing systematic reviews and identifying new studies, evidence of the effect of hand hygiene interventions on infection incidence in educational settings is mostly equivocal but they may decrease RT infection among children. These results update and add to knowledge about this crucial public health issue in key settings with a vulnerable population. More robust, well reported cluster RCTs which learn from existing studies, are required.
To understand the transmission of respiratory syncytial virus, we examined the frequency of infection in volunteers after inoculation by different routes with varying doses of virus. Thirty-two adult volunteers received serial dilutions of a safety-tested live strain of respiratory syncytial virus instilled into nose, eye, or mouth. The highest inoculum, 5.2 log10 50% tissue culture infective dose (TCID50), was administered to four groups of four subjects each, by nose to one group, by eye to one group, and by mouth to two groups. Subsequently, 1:100 and 1:1,000 dilutions of this inoculum were administered by nose and eye. At the highest inoculum, infection occurred in three of four subjects inoculated by nose and in three of four subjects inoculated by eye. Infection occurred in one of eight subjects inoculated by mouth, but this subject most likely was infected by secondary spread. With an inoculum of 3.2 log10 TCID50, the proportion of subjects infected by either route diminished to 25%. When the inoculum was further reduced to 2.2 log10 TCID50, no infections occurred by either route. Infections after the highest inoculum were characterized by earlier and greater shedding. These findings suggest that respiratory syncytial virus may infect by eye or nose and that both of these routes appear equally sensitive. In comparison, the mouth appears to be an insensitive route of inoculation. This is of potential import in infection control procedures and in the development of vaccines or other prophylactic measures.
The aim of the study was to determine the prevalence of E. coli and Citrobacter freundii contamination in beef from major abattoirs. A total of 34 meat samples were examined for the prevalence of Escherichia coli and Citrobacter freundii. They were randomly collected from different areas in Damascus and its countryside, from Slaughterhouses (from the thigh area of beef) They were performed using macConkey agar and EMB (Eosin Methylene Blue) agar. The API 20E system BioMérieux company – France was used to distinguish, coliform bacteria and E.coli that isolated on the selective culture. Out of 117 total isolates, 35 isolates (29.9%) were Escherichia coli and 2 isolates (1.7%) were Citrobacter freundii. It must be used good healthy measures like, periodic cleaning for tools and surfaces contact to the meat during skinning and slicing of the meat in order to reduce the potential contamination.
The transfer of gram-positive bacteria, particularly multiresistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE), among patients is a growing concern. One critical aspect of bacterial transfer is the ability of the microorganism to survive on various common hospital surfaces, The purpose of this study was to determine the survival of 22 gram-positive bacteria (vancomycin-sensitive and -resistant enterococci and methicillin-sensitive and -resistant staphylococci) on five common hospital materials: smooth 100% cotton (clothing), 100% cotton terry (towels), 60% cotton-40% polyester blend (scrub suits and lab coats), 100% polyester (privacy drapes), and 100% polypropylene plastic (splash aprons), Swatches were inoculated with 10(4) to 10(5) CFU of a microorganism, assayed daily be placing the swatches in nutritive media, and examining for growth after 48 h, All isolates survived for at least 1 day, and some survived for more than 90 days on the various materials. Smaller inocula (10(2)) survived for shorter times but still generally for days, Antibiotic sensitivity had no consistent effect on survival, The long survival of these bacteria, including MRSA and VRE, on commonly used hospital fabrics, such as scrub suits, lab coats, and hospital privacy drapes, underscores the need for meticulous contact control procedures and careful disinfection to limit the spread of these bacteria.
Placing children in grocery shopping carts has been implicated recently as a source of infection with Salmonella and Campylobacter in young children. This study was conducted to assess the occurrence total bacteria, coliform bacteria and Escherichia coli on grocery shopping cart handles and seats. A total of 85 shopping carts in parking lots of grocery stores were tested in five major metropolitan areas across the United States. The total numbers of heterotrophic bacteria were as great as 1.1 × 107 on the handle and seat. Coliforms were detected on 72% (62) of the carts. E. coli was identified on 18 of 35 carts (51%) on which coliform identification was conducted. The results of this study suggest the need for improved sanitation of shopping cards/baskets to reduce exposure to pathogens and potential transmission of microbial infections among shoppers.
Background: The hygiene of environmental surfaces from shopping, ATM machines, telephones and computers and miscellaneous sites play role in spreading fecal and total coliform bacteria as well as pathogenic bacteria. Objectives: This study addresses the contaminated common sites by pathogenic or potentially pathogenic bacteria in Mecca, SA. Materials and Methods: A total 648 swab samples were collected and analyzed for presence or absence of pathogenic bacteria. Results: Of the total samples 422 were negative bacterial count (71%) and 226 (29%) were positive. All collected samples (100%) of glass windows in the fish markets were bacterial counted; most dominated was Bacillus spp. (n = 97) and the highest population of species was Enterococcus faecalis (n = 40) and E. coli (n = 16). Conclusion: Some public sites were very contaminated with different types of fecal coliform group of bacteria such as shopping cart handles, inner surfaces and child seats in supermarkets, and the glass windows in the fish market. Acinetobacter haemolyticus and other hemolytic bacteria were isolated from more than site.