[Show abstract][Hide abstract] ABSTRACT: The emergence of antibiotics resistant bacteria in the water environment is becoming an increasing worldwide concern. This study was conducted to highlight the importance of the Wastewater Treatment Plants in the purification of raw water and the elimination of resistant bacteria such as Salmonella circulating in the environment. The results showed the presence of Salmonella in sewage only and total absence in the treated water; a total of forty two strains of Salmonella were isolated, serotyping of these strains showed six different serotypes of Salmonella spp which 57.1% were Salmonella typhimurium, antibiotic resistance was studied and different antibiotics were tested by the method of Mueller Hinton agar diffusion. The antimicrobials and concentrations in μg tested were: Amikacin 30 (Ak), Ampicillin 10 (Amp), Choramphenicol 10 (Chl), Cephalotine 30 (Cef), Ceftazidime 30 (Caz), Trimethoprim /Sulfametoxazole 1.25/23.75(Sxt), Cefotaxime 30 (Ctx), Gentamicin 10 (Gen), Imipenem 10 (Ip), Kanamycin 30 (Kan), Streptomycin 10 (Str), Tetracycline 30 (Tet), Sulfonamides 200 (Su), Ciprofloxacine 5 (Cip); The results showed the presence of multi-resistant strains.
European Journal of Scientific Research 01/2012; Vol.68(No.4 (2012)):pp. 565-573. · 0.74 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Shiga toxin Escherichia coli (STEC), also called verotoxin-producing E. coli, is a major cause of food-borne illness, capable of causing hemorrhagic colitis and hemolytic-uremic syndrome (HUS). This study was carried out to evaluate the presence of (STEC) and E. coli O157:H7 in shellfish and Mediterranean coastal environments of Morocco. The contamination of shellfish and marine environment with Shiga toxin-producing E. coli (STEC) and E. coli O157:H7, was investigated during 2007 and 2008. A total of 619 samples were analyzed and 151 strains of E. coli were isolated. The presence of the stx1, stx2, and eae genes was tested in E. coli isolates strains using a triplex polymerase chain reaction. STEC was detected in three positives samples (1.9%), corresponding to the serotype O157:H7, the others Shiga toxin-producing E. coli non-O157 were also detected.
[Show abstract][Hide abstract] ABSTRACT: The contamination of meat and meat products with Shiga toxin-producing O157:H7 and non-O157 Escherichia coli (STEC), obtained from markets in Casablanca, Morocco, was investigated. A total of 460 meat and meat products were sampled between March 2004 and July 2006 analysed and 176 strains of E. coli were isolated from these samples. The presence of the stx1, stx2, eae and ehxA genes, recognized as major virulence factors of STEC, was tested in E. coli isolates by polymerase chain reaction (PCR). STEC was detected in 4 (0.9%) samples. The result of serotyping by molecular method showed that two of these STEC isolates corresponded to the serotype O157:H7. The others Shiga toxin-producing E. coli non-O157 corresponded to O6:H21 and O76:H19. The presence of O157:H7 and non-O157 STEC in meat and meat products marketed in Casablanca, Morocco, emphasizes the importance of implementing the Hazard Analysis and Critical Control Point (HACCP) system, as well as the need for implementing, evaluating, and validating antimicrobial interventions to reduce the presence of potential pathogenic microorganisms.
[Show abstract][Hide abstract] ABSTRACT: In order to develop other molecular method useful for typing of motile and non motile Escherichia coli strains, a total of 207 strains of E. coli (133 reference strains, 74 food strains) were characterized by analysis of sequences of their amplified flagellin-encoding (fliC) gene products. The collection of reference strains was used for database building of fliC gene sequences. Application of this identification system to 74 E. coli food isolates revealed a reproducible and clear cut classification with very good correlation to results obtained by HhaI restriction of the amplified flagellin gene. The proposed determination of fliC sequences variations should be helpful for epidemiological studies.
The Journal of Microbiology 04/2010; 48(2):184-7. DOI:10.1007/s12275-010-9182-1 · 1.44 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study was undertaken to determine the frequency of potentially pathogenic Escherichia coli (E. coli)
strains among E. coli isolated from Casablanca, Morocco. The E. coli strains were isolated from ground beef
(n = 140), turkey (n = 200), sausage (n = 120), seafood (n = 60), domestic water (n = 35) and well water
(n = 50). The prevalence of E. coli was 48%, 45%, 35.5%, 30%, 8.3%, 0%, for well water, ground beef, turkey,
sausage, sea food and domestic water, respectively. Two hundreds E. coli isolates were tested for the presence
of 17 virulence genes associated with strains causing intestinal and extra-intestinal infections. The
virulence genes included stx1, stx2, lt, st, hlyA, aggA, saa, astA, iucD, cnf1, eaeA, bfpA, ial, ipaH, afa, pap and
sfa. PCR showed that 37% (74) of E. coli isolates carried one or more of these virulence genes. No virulence
genes were found in E. coli strains isolated from sea food samples. In contrast, 10% of the ground beef
samples, 18% of the turkey samples, 17.5% of sausage samples and 6% of well water contained specific
factors for intestinal E. coli pathogens.
Food Control 05/2009; 20(20):560–564. DOI:10.1016/j.foodcont.2008.08.015 · 2.81 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Serotyping of O- and H-antigens is regarded as the gold standard in classification of E. coli for taxonomic and
epidemiological purposes similar to the Kaufmann-White scheme for Salmonella enterica. Molecular methods to replace or
to support the serotyping were recently applied. Using the molecular polymorphism of the somatic (O-antigen) gene rfb
cluster and flagella (H-antigen) gene fliC, 74 E. coli strains carrying the virulent genes isolated from food were characterised
by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results showed that 49 (66%) of
the isolates revealed a reproducible and clear cut classification, with a very good correlation to the collection of reference
strains, were found.
Cellular and molecular biology 01/2009; 55:1132-1137. · 1.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The in vitro susceptibilities to several antibiotics of 140 Escherichia coli (E. coli) isolated from food were analysed. Eighty five (61%) of the isolated E. coli strains did not contain virulence factors, whereas 55 (39%) of them contained one or more virulence factors. E. coli strains were analysed by polymerase chain reaction for genes encoding the following virulence factors: aerobactin (iucD); EAggEC heat-stable enterotoxin (astA); intimin (eaeA); shigatoxin (vt); pyelonephritis-associated pili (pap). It was observed that the virulence genes increased antibiotic resistance of resistant strains and
[Show abstract][Hide abstract] ABSTRACT: Serotyping of O- and H- antigens is regarded as the gold standard in classification of E. coli for taxonomic and epidemiological purposes similar to the Kaufmann-White scheme for Salmonella enterica. Molecular methods to replace or to support the serotyping were recently applied. Using the molecular polymorphism of the somatic (O- antigen) gene rfb cluster and flagella (H- antigen) gene fliC, 74 E. coli strains carrying the virulent genes isolated from food were characterised by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results showed that 49 (66%) of the isolates revealed a reproducible and clear cut classification, with a very good correlation to the collection of reference strains, were found.
[Show abstract][Hide abstract] ABSTRACT: The genetic diversity of 74 isolates of Escherichia coli (E. coli) recovered from ground beef, sausage, turkey and well water samples was examined by PFGE (Pulsed field gel electrophoresis) of chromosomal DNA digested with XbaI. The E. coli isolates were classified into different serotypes obtained by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and expressing various fliC gene and toxic virulence markers. The restriction pattern profiles showed a high degree of polymorphism among isolates of different serotypes and a close relationship between strains belonging to the same serological group. In addition, some bacterial strains with identical virulence determinants exhibited distinct PFGE types. The results obtained showed that PFGE analysis is a powerful tool to reveal the clonal nature and genetic differences among potentially pathogenic E. coli strains
[Show abstract][Hide abstract] ABSTRACT: In this study, samples of raw ground beef (n = 150) and fresh sausage (n = 100) were collected randomly from butcheries, supermarkets, and fast-food shops, in Casablanca, Morocco. Two types of meat product samples were considered, one with spices (n = 115) and other without spices (n = 135). All the samples were analyzed for the presence of the following bacteria: Escherichia coli, Staphylococcus, Clostridium perfringens, Salmonella, and Listeria monocytogenes. E. coli strains were further typed by pulsed-field gel electrophoresis (PFGE), Operon O, and characterized for virulence genes by polymerase chain reaction (PCR). Results indicated that counts of E. coli, coagulase-positive Staphylococcus, and C. perfringens were 17%, 9.6%, and 8.7% in samples without spices, respectively; and 23.5%, 23.7%, and 29.6% in samples with spices, respectively. Two pathogenic genes, LT and EAST, were identified separately in four strains of E. coli. Salmonella and L. monocytogenes were isolated in 2.8% and 3.2% of the total samples, respectively.
Journal of environmental health 12/2008; 71(4):51-5, 63. · 0.96 Impact Factor