Prevalence of Salmonella Species
in Various Raw Meat Samples
of a Local Market in Kathmandu
MAHENDRA MAHARJAN,aVANDANA JOSHI,aDURGA D. JOSHI,b
AND POORNIMA MANANDHARc
aCentral Department of Zoology (Parasitology), Tribhuvan University,
bNational Zoonoses and Food Hygiene Research Centre, Tahachal,
cCentral Veterinary Laboratory, Veterinary Complex, Tripureshor,
ABSTRACT: A cross-sectional study of raw meat samples from the local
meat market of Kathmandu Metropolitan City was carried out during
September 2002 to May 2003 with special emphasis on isolation and
identification of Salmonella bacteria. A total of 123 raw meat samples
(55 chicken, 37 buffalo, and 31 goat) were collected and analyzed rela-
and one sample of goat (3.3%) were found to be positive for Salmonella.
Salmonella prevalence revealed Salmonella (S.) pullorum in 3.3% sam-
ples, S. gallinarum in 0.8%, S. typhi in 1.6%, S. choleraesuis in 0.8%,
and Salmonella of subgenus I or II group in 4.9% samples. More than
80% meat samples microbiologically processed indicated coliform con-
of April/May. Surveys revealed unsatisfactory conditions of sanitation in
the local meat markets of Kathmandu.
KEYWORDS: Salmonella; chicken; buffalo; goat; local market; Nepal
value having both essential macro- and micronutrients makes it an important
part of a balanced diet for most people. Unfortunately, meat is also a suitable
Address for correspondence: Mahendra Maharjan, Central Department of Zoology (Parasitol-
ogy), Tribhuvan University, Kirtipur, GPO Box: 23414, Kathmandu, Nepal. Voice: +977-1-4312314;
e-mail: mahendra firstname.lastname@example.org
Ann. N.Y. Acad. Sci. 1081: 249–256 (2006). C ?2006 New York Academy of Sciences.
250ANNALS NEW YORK ACADEMY OF SCIENCES
gastroenteritides in humans.1Worldwide, salmonellosis is a leading cause of
enteric infectious disease attributable to foods. Salmonella (S.) is one of the
major meat and meat product-associated bacterial pathogen in relation to the
increased salmonellosis cases in the world during the last 20 years.2
Improperly cooked chicken, eggs, and other chicken products are responsi-
improperly cooked meats particularly beef and pork, that is, 13%.3Other than
bacteria may be present in low levels in muscle tissue, but these are not the
most common source of contamination. Extrinsic factors are by far the great-
and meat handling practices contribute greatly to the spread of this disease.
Meat carcasses may become contaminated from fecal material, paunch con-
tent, and from the hide.4Additional sources of cross-contamination exist in
carcass contact.5Large meat animals undergo a significant amount of cutting
and boning in order to result finished products. Each time the carcass is cut,
Immediately after slaughtering, the principal types of bacteria found on car-
casses are animal strains; by the time the final cuts reach the retail consumer
level, however, human strains become prevalent.6
Eggs, chicken, meat, and meat products are the most common food vehicles
of salmonellosis to humans. In America and Europe S. enteritidis has become
the predominant strain and outbreaks are related to eating of chicken or eggs
from hens whose ovaries are colonized by S. enteritidis.7
In Nepal, buffalo contribute about 64% of meat consumed, followed by
goat 20%, pork 7%, and chicken 6%.8The subtropical climate, poor sanitary
conditions, improper storage facilities, poor food hygiene practices, and lack
of prevention against diseases in Nepal have all contributed to a number of
diseases originating from meat.
Consumption of meat is highest in Kathmandu, a capital city where more
than 90% people are nonvegetarian. Due to lack of sufficiently well-organized
slaughter houses, poor hygiene in the meat shops, and shortage of clean water,
meat in Kathmandu is subject to contamination. Enteric fever is endemic in
the Kathmandu valley. The disease flares to epidemic proportion from time
to time.9This article deals with the slaughtering facilities and practices in a
typical market place in Kathmandu and reports the isolation of Salmonella
spp. in consumable meat.
MATERIALS AND METHODS
A total of 123 different raw meat samples were collected from 40 identi-
fied meat shops (28 registered and 12 not registered) in a Kathmandu local
MAHARJAN et al.: PREVALENCE OF SALMONELLA SPECIES251
December, 2002; and April/May, 2003.
Approximately 1–2 mL of chicken, buffalo, and goat meat samples were
to the laboratory in sterile vials, and examined for bacteria.
After pre-enrichment, one loopful sample of the peptone water was taken
and streaked on eosin methylene blue media for the detection of E. coli and
on MacConkey agar to detect lactose fermenting and nonlactose fermenting
bacteria. The inoculated plates were incubated for 24 h at 37◦C.
A loopful of enriched samples (incubated at 43◦C for 24 h) were taken and
streaked on bismuth sulphite agar (BSA) by the quadrant streak method for
daily for 7 days unless the culture was obtained.
Isolates from BSA agar were streaked onto brilliant green agar (BGA) and
xylose lysine deoxycholate (XLD) agar. The inoculated plates were incubated
for 48 h at 37◦C. The colonies of Salmonella were streaked from sub-culture
agar to nutrient agar for pure culture and incubated at 37◦C for 24 h for the
Identification of Isolated Salmonella Species
The typical colonies of Salmonella on BSA, BGA, and XLD were iden-
tified by their morphological characteristics and biochemical tests.11,12The
primary test includes motility, Gram’s stain, catalase, oxidase, and oxida-
tion/fermentation test followed by secondary/biochemical tests.
To confirm the Salmonella obtained in culture media during the process
of identification, agglutination test was carried out by using two types of
antiserums: Poly O sera and Oxoid Latex Test Reagent.
252ANNALS NEW YORK ACADEMY OF SCIENCES
TABLE 1. Species wise prevalence of Salmonella in Kathmandu local market
Positive cases out
of 123 samples IsolatesPercentage
Salmonella of subgenus I or II group
In Kathmandu meat markets, various kinds of meat are sold. Some shops
sell meat from one species only. Samples were collected from 12 goat shops,
24 chicken shops, and 14 buffalo shops with 10 shops keeping both chicken
and goat. During the survey, it was found that the chickens and goats were
slaughtered either in or around shops and sometimes along the roads. Buffalo
were slaughtered outside the shop and only carcasses were brought to the shop
Most shops (24) used hot water for cleaning chicken and goats, but repeated
use of water was found to be common. Cold water was used generally for
buffalo meat. An irregular water supply to most of the shops made washing
practices more difficult and consequently, washing utensils and knives were
infrequently practiced. Out of 40 shops only 16 shops (40%) had refrigeration
available. Covering and hanging of carcass was unusual.
Prevalence of Salmonella Species in Various Raw Meat Samples
Out of 123 samples tested 14 (11.4%) samples were found to be positive
for various species of Salmonella. S. pullorum was found in 3.3% samples,
of subgenus I and II in 4.9% samples (TABLE 1). Salmonella prevalence in
various raw meat samples collected from the market showed that 14.5% in
chicken, 13.5% in buffalo, and 3.2% in goats (TABLE 2).
Out of 55 chicken samples, 8 were found to be positive for Salmonella,
among them 4 were S. pullorum, 1 was S. gallinarum, and 3 isolates were
of Salmonella of subgenus I or II type. Most of the Salmonella isolates from
poultry samples were found to be of the contaminant type, since S. pullorum
and S. gallinarum are Salmonella types adapted to poultry. Among 5 buffalo
isolates, 2 were S. typhi 1 was S. choleraesuis, and 2 were Salmonella of
subgenus I and II group. S. typhi and S. choleraesuis are Salmonella types
not adapted to cattle. S. typhi is human adapted type and S. choleraesuis is
swine adapted type. Thus their presence in buffalo samples may be the case
of extrinsic contamination. Salmonella of subgenus I or II group were isolated
MAHARJAN et al.: PREVALENCE OF SALMONELLA SPECIES 253
TABLE 2. Prevalence of Salmonella in various raw meat samples of Kathmandu local market
Growth in MacConkey agar
Growth in EMB agar
BSA agar +ve
Lac. fer. = lactose fermenting; Non lac. fer. = nonlactose fermenting; +ve = positive.
254ANNALS NEW YORK ACADEMY OF SCIENCES
TABLE 3. Species wise prevalence of Salmonella in various raw meat samples
Salmonella of subgenus I or II
Salmonella of subgenus I or II
Salmonella of subgenus I or II
from all species and could not be differentiated, but subgenus I includes type
species like S. entiritidis that is a very prevalent species(TABLE 3).
Seasonal Variation of Salmonella Species Contamination
in Various Raw Meat Samples
The presence of Salmonella in meat samples were found to be highest in the
months of April/May (summer season) at 18% while in September/October
(autumn) it was found to be only 4.3%. Salmonella was isolated from 13.15%
of samples in the months of November/December (FIG. 1).
DISCUSSION AND CONCLUSION
husbandry in developing countries and development of different types of food
of animal origin, new problems of food-borne zoonotic diseases are arising.
Seasonal variation of the Salmonella
contamination in various raw meat samples
No of percentage
FIGURE 1. Seasonal variation of the Salmonella contamination in various raw meat
MAHARJAN et al.: PREVALENCE OF SALMONELLA SPECIES255
Parasitic and zoonotic food-borne diseases are particularly prevalent in trop-
ical and subtropical countries. There are a number of factors responsible for
the spread of zoonotic disease, such as salmonellosis. Clean washing water is
critical. Sanitation and clean water use during the slaughtering and processing
of meat can protect the meat from contamination. This study of meat shops in
Kathmandu revealed that most of the shops do not operate in a safe and clean
environment. Covering and hanging carcasses were rarely practiced. Further,
uninfected carcass increases. It is well documented that Listeria spp. staphylo-
coccus aureus, yersinea enterocolitica, Salmonella, and Aeromonas spp. may
be detected in slaughter house environment, for example, on floor and walls,
cold room floor, hand basins, splitting saws, chopping blocks, etc. The pro-
cessing of carcass into parts further spreads contamination by exposing more
carcass surface and susceptible fleshy parts to the contaminants if the same
cutting tables and knives are used.6
The shops using cold water were at high risk of using contaminated water
for the processing of meat. A survey of the ground water quality of an urban
area of the Lalitpur district of Nepal showed that 85.6% samples of water from
different sources were positive for fecal contamination. Salmonella species
were detected in 10.8% of the sources.13
We are very much thankful to the Royal Nepal Science and Technology
(RONAST) for providing partial grant to Vandana Joshi. The Head of the
Central Department of Zoology, the Director of the Central Veterinary Labo-
ratory, and the National Zoonoses and Food Hygiene Research Centre are also
acknowledged for providing laboratory facilities during the study period.
1. STEELE, J.H. & M.M. GALTON. 1998. Epidemiology of food borne salmonellosis.
Health Lab. Sci. 4: 207–212.
2. WHO. 1982. Bacterial and viral zoonoses. Tech. Report Series. 682: 7–9.
3. CENTER FOR DISEASE CONTROL AND PREVENTION. 1999. Outbreak of Salmonella
serotype muenchen infection associated with unpasteurized orange juice. US.
Canada 48: 582–585.
4. LAHR, J.A. 1996. Beef carcass microbial contamination-post slaughter number of
bacteria, sources of contamination and variability. Proceeding of 49th Annual
Reciprocal Meats Conference. 132–137. Provo, Utah.
5. HUFFMAN, R.D. 2002. Current and future technologies for the decontamination of
carcass and fresh meat. ICoMST-Rome 1: 9–14.
6. MORTON, S. 2002. Use of irradiation for microbial decontamination of meat: sit-
uation and perspective. 48th ICoMST Room 1: 3–7.
256ANNALS NEW YORK ACADEMY OF SCIENCES Download full-text
7. MORRIS, E.P., M. YASMIN & K.K. FRITZ. 1997. Emerging of foodborne diseases.
World Health Organization. Geneva, Switzerland 1: 16–17.
8. JOSHI, D.D., M. MAHARJAN, M.V. JOHNSEN, et al. 2003. Improving meat inspection
and control in resources poor communities. The Nepal example. Acta Tropica
9. MALLA, F.B. & G.M. SAKYA. 1984. Enteric fever—a review of clinical records. J.
Nep. Med. Assoc. 22: 9–15.
10. ELIZABETH, O.K. 1975. The identification of unusual pathogenic gram negative
bacteria. First edition. U.S. Department of Health, Education and Welfare Public
Health Service, Atlanta, Georgia.
11. COWAN, S.T. 1974. Cowan and Steele’s Manual for the Identification of Medical
Bacteria, 2nd ed. Cambridge University Press. London.
12. HOLT, J.G., N.R. KRIEG, P.H.A. SNEATH, et al., Eds. 1994. Bergey’s Manual of De-
terminative Bacteriology London. 9th ed. The Williams and Wilkins Company.
13. MAHARJAN, M. & A.P. SHARMA. 2000. Bacteriological quality of ground water in
urban Patan and antibiotic sensitivity against isolated enteric bacteria. J. Nep.
Med. Assoc. 39: 269–274.