Prevalence of <Emphasis Type="Italic">Campylobacter</Emphasis> spp. in poultry and poultry products for sale on the Bulgarian retail market

The aim of this study was to investigate the presence of Campylobacter spp. in poultry and poultry products available for the consumers at retail markets in Bulgaria. Samples (n = 210) of poultry carcasses and poultry products for sale at the retail market in Bulgaria were analysed for the presence of Campylobacter spp., of these 35 frozen whole carcasses, 135 chilled poultry cuts (45 wing cuts, 45 thigh cuts and 45 fillet) and 40 thermally treated (ready-to-eat) poultry products. The results obtained showed that 35.2% of the frozen poultry carcasses for sale in the markets were Campylobacter contaminated. In the chilled poultry cuts Campylobacter was isolated at the highest percentage in wing- and thigh cuts, 91.1% and 88.9%, respectively. The fillet samples were contaminated by Campylobacter in 48.9% of cases. In the chilled poultry products as well as in the frozen carcasses C. jejuni (74.8%/70.3%) was the most commonly isolated Campylobacter species, with the remainder being C. coli (25.2%/29.7%). Campylobacter spp. were not detected in the thermally treated poultry products.     

Observations on the Microbiology of Cooked Chicken Carcasses

S ummary . The residual microbial flora and the flora developing during storage at 1–3° and at 16°, of chicken carcasses cooked in a circulating moist air oven operated at 85°, have been studied. All parts of the carcasses reached and maintained 85° for at least 50 min, and the residual flora consisted largely of spore forming bacteria. The predominant residual species were Bacillus subtilis and Clostridium bifermentans. Non-sporing bacteria were not detected after cooking nor after storage at 1–3° for up to 7 days. Storage at 16° for 3 days markedly increased the number of non-sporing organisms although off-odours typical of spoilage were not apparent until at least 10 days. Staphylococcus aureus and Salmonella spp. were not detected after cooking and storage and Cl. welchii was rarely isolated. It is concluded that poultry cooked by this method present a minimal risk of food-borne infection or intoxication by these organisms if contamination after cooking is avoided, the carcasses are cooled rapidly to c , 3° and stored at this temperature or frozen.     

Survival of Campylobacter jejuni on beef trimmings during freezing and frozen storage

AIMS: To investigate the survival of two animal isolates of Campylobacter jejuni on beef trimmings during freezing and frozen storage. METHODS AND RESULTS: Meat packs inoculated with 10(3) or 10(6) cfu g(-1) of either strain of C. jejuni were frozen to -18 degrees C, and sampled at regular intervals over 112 d storage to determine Campylobacter numbers and sublethal injury. For both strains and inoculation levels the numbers of Campylobacter decreased in the first 7 d of storage by ca. 0.6-2.2 log cfu g(-1) and then remaining constant over the remainder of the storage trial, with neither isolate exhibiting sublethal injury. CONCLUSIONS: Despite an initially significant decrease in number, these pathogens were able to survive standard freezing conditions in meat, but did not exhibit sublethal injury. SIGNIFICANCE AND IMPACT OF THE STUDY: Strict hygiene and/or the implementation of decontamination technologies are recommended as a means to assure the safety of meat with respect to this pathogen.     

Presence of Listeria and Salmonella spp. in retail chicken in Northern Ireland

AIMS: Retail packs of fresh chicken in Northern Ireland were sampled to determine the frequency with which they were contaminated with Salmonella and Listeria spp. METHODS: Packs of chicken were chosen from supermarkets ensuring a diverse range of EU producer codes were sampled. Salmonellas were isolated using BS EN 12824: 1998 methodology, biotyped and serotyped whilst Listeria spp. were isolated based on EN ISO 11290-1: 1996 procedures and identified using a multiplex PCR system utilizing genus and species specific primers. SIGNIFICANCE AND IMPACT OF THE STUDY: Only three of 205 samples yielded Salmonella spp. indicating that measures undertaken by the poultry industry to control this pathogen have apparently been successful. However, Listeria spp. were present in 38 of 80 samples tested (48%) and 14 (18%) yielded Listeria monocytogenes. Thus Salmonella controls do not markedly affect this pathogen and retail packs of raw chicken must be considered a potential source of L. monocytogenes, and appropriate precautions taken to prevent infection.     

Intestinal carriage of campylobacters, salmonellas, yersinias and listerias in pigeons in the city of Barcelona

L. CASANOVAS, M. DE SIMÓN, M.D. FERRER, J. ARQUÉS AND G. MONZÓN. 1995. The faecal bacterial flora of pigeons, which may be the source of infectious diseases in man, was studied in the city of Barcelona. Four hundred cloacal specimens were examined for Campylobacter jejuni, Camp. coli, Salmonella spp., Yersinia spp. and Listeria spp., over a 12 month period.
Campylobacter jejuni was the most frequently isolated micro-organism, found in 105 pigeons (26.2%), with a greater incidence in the districts of the city with a high density of pigeons and without seasonal variation. Salmonella spp. were isolated from six specimens (1.5%) and Yersinia intermedia was isolated from only one pigeon.     

Carriage of four bacterial pathogens by beef cattle in Northern Ireland at time of slaughter

AIMS: To determine the prevalence of four bacterial zoonotic pathogens in beef cattle at time of slaughter in Northern Ireland (NI), in order to assess their potential for reducing beef safety. METHODS AND RESULTS: Faeces were collected postmortem from beef cattle (n =220) at seven EU registered abattoirs. Standard enrichment culturing methods were employed, plus immunomagnetic enrichment in the case of Escherichia coli O157:H7. Campylobacter spp. were found in 52 samples (24.8%), Listeria monocytogenes in 10 (4.8%), E. coli O157:H7 in 2 (0.9%) whilst Salmonella spp. were isolated from six out of 200 samples (3.0%). Five salmonellas were Salmonella Chandans and one was Salmonella Liverpool. CONCLUSIONS: Campylobacter spp. were the most frequently isolated pathogen, despite being relatively rare in beef. Genotyping showed the campylobacters to be very diverse, indicating cattle encounter campylobacters from many sources. The remaining three pathogens, which are associated with meats, occurred at relatively low frequencies, especially E. coli O157:H7. The Salmonella serovars found rarely infect humans. SIGNIFICANCE AND IMPACT OF THE STUDY: The low prevalence of E. coli O157:H7 in NI beef cattle was confirmed and the reasons for this merit further study. The four pathogens should have little impact on beef quality.     

Occurrence and persistence of bacterial pathogens and indicator organisms in beach sand along the California coast

This report documents the presence of fecal indicators and bacterial pathogens in sand at 53 California marine beaches using both culture-dependent and -independent (PCR and quantitative PCR [QPCR]) methods. Fecal indicator bacteria were widespread in California beach sand, with Escherichia coli and enterococci detected at 68% and 94% of the beaches surveyed, respectively. Somatic coliphages and a Bacteroidales human-specific fecal marker were detected at 43% and 13% of the beaches, respectively. Dry sand samples from almost 30% of the beaches contained at least one of the following pathogens: Salmonella spp., Campylobacter spp., Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus (MRSA), which were detected at 15%, 13%, 14%, and 3% of tested beaches, respectively. Fecal indicators and pathogens were poorly correlated to one another and to land cover. Sands were dry at the time of collection, and those with relatively high moisture tended to have higher concentrations or a more frequent occurrence of both indicators and pathogens. Using culture-dependent assays, fecal indicators decayed faster than pathogens in microcosm experiments using unaltered beach sand seeded with sewage and assessed by culture-dependent assays. The following order of persistence was observed (listed from most to least persistent): Campylobacter > Salmonella > somatic coliphages > enterococci > E. coli > F(+) phages. In contrast, pathogens decayed faster than fecal indicators in culture-independent assays: enterococci > Bacteroidales human-specific marker > Salmonella > Campylobacter. Microcosm experiments demonstrated that both indicators and pathogens were mobilized by wetting with seawater. Decay rates measured by QPCR were lower than those measured with culture-dependent methods. Enterococcal persistence and possible growth were observed for wetted microcosms relative to unwetted controls.     

Prevalence of bacterial faecal pathogens in separated and unseparated stored pig slurry

AIMS: To examine the prevalence and diversity of bacterial faecal pathogens in unseparated slurry, separated solids and liquid fractions from a commercial pig farm. METHODS: A total of 43 stored slurry specimens originating from a fattening house over the period February-April 2002 were analysed, consisting of unseparated (n = 14) slurry, separated solids (n = 16) and separated liquid (n = 13). Specimens were examined for the presence of five bacterial pathogens including Salmonella spp., Shigella spp., Campylobacter spp., Escherichia coli O157 and Yersinia enterocolitica. Selective enrichment and plating methods were employed for detection of Salmonella spp. and Campylobacter spp. and conventional selective plating techniques for the remaining genera. Antibiogram profiles to 12 antibiotic agents were obtained for all Salmonella isolates obtained. RESULTS: Salmonella spp. were identified in all components of the slurry specimens, whereas Campylobacter spp. was only recovered from the unseparated and separated liquid fractions. In both cases, the separated liquid fraction had the highest prevalence of pathogens and the separated solid fraction had the lowest prevalence. None of the slurry specimens examined were positive for E. coli O157:H7, Shigella spp. or Y. enterocolitica. Twenty-nine isolates of Salmonella were recovered from the slurry specimens, comprising seven serovars, of which Salmonella manhattan was the most prevalent, accounting for over half [15 of 29 (51.7%)] of all Salmonella isolates. Salmonella anatum, Salm. derby, Salm. give, Salm. heidelberg, Salm. simi and Salm. stanley serovars were also recovered. All Salmonella isolates were sensitive to ampicillin, augmentin (amoxicillin/clavulanic acid), chloramphenicol, ciprofloxacin, gentamicin, kanamycin and trimethoprim, but has variable resistance to tetracycline (100%), sulphonamides (84.6%), furazolidone (38.5%), nalidixic acid (15.4%) and streptomycin (15.4%). The majority (57.7%) of isolates displayed antibiotic resistance to at least two antibiotic agents, followed by 34.6% of isolates being resistant to three agents and the remainder (7.7%) being resistant to four antibiotics. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrated a marked reduction in the prevalence of Campylobacter and Salmonella in the solids component of separated pig slurry. The adoption of control processes such as aeration of slurry prior to its spread onto agricultural land and newer approaches to pathogen reduction should be investigated, to reduce the transmission of pathogens from pig slurry to the environment.     

Microbiological quality of blue mussels (Mytilus edulis) in Nunavik, Quebec: a pilot study

This pilot study was aimed at documenting the presence of fecal indicators and enteric pathogens in blue mussels (Mytilus edulis) from 6 communities in Nunavik, Quebec. One to four 2?kg samples of mussels were collected at low tide in each community. Samples were investigated by enumeration methods for the fecal indicators enterococci, Escherichia coli, F-specific coliphages, Clostridium perfringens, and by molecular identification for the pathogens norovirus, Salmonella spp., Campylobacter jejuni, Campylobacter coli, and Campylobacter lari, verocytotoxin-producing E.?coli (particularly serovar O157:H7), Shigella spp., and Yersinia enterocolitica. In 5 communities, the presence of Giardia duodenalis and Cryptosporidium spp. was also tested by microscopy and molecular methods and that of Toxoplasma gondii was tested by molecular methods. Apart from small quantities of Clostridium perfringens in 2 samples, no bacterial or viral pathogens were detected in the mussels. Toxoplasma gondii was also not detected. However, G.?duodenalis and Cryptosporidium spp. were present in 18% and 73% of the samples investigated for these pathogens, respectively. When considering the indicators and the viral and bacterial pathogens investigated, the mussels examined were of good microbiological quality, but considering the presence of potentially zoonotic protozoa, it should be recommended that consumers cook the molluscs well before eating them.     

The microbiological examination of ready-to-eat organic vegetables from retail establishments in the United Kingdom.

AIMS: A microbiological study of uncooked ready-to-eat organic vegetables was undertaken to determine the microbiological quality of these vegetables on retail sale in the UK. METHODS AND RESULTS: Organic vegetables were collected and examined according to a standardized protocol. The majority (3185 of 3200; 99.5%) of samples were found to be of satisfactory/acceptable quality whilst only 15 (0.5%) were of unsatisfactory quality. Unsatisfactory results were due to Escherichia coli and Listeria spp. (not L. monocytogenes) levels in excess of 102 cfu g-1. CONCLUSIONS: The absence of pathogens (L. monocytogenes, Salmonella, Campylobacter and E. coli O157) and the low incidence (1.5%) of E. coli and Listeria spp. associated with these organic vegetables indicates that overall agricultural, hygiene, harvesting and production practices were good. SIGNIFICANCE AND IMPACT OF THE STUDY: There has been a significant expansion of the UK organic market since 1998/99. Of the various commodity sectors making up the organic market, fruit and vegetables is the largest sector and this has been reflected in an increased interest in their microbiological safety. This is the first study to provide information on the microbiological quality of organic vegetables.     

Declines of zoonotic agents in liquid livestock wastes stored in batches on-farm

AIM: To measure the decline rates of zoonotic agents introduced into liquid livestock wastes in on-farm storage tanks. METHODS AND RESULTS: Salmonella spp., Escherichia coli O157, Campylobacter jejuni, Listeria monocytogenes and Cryptosporidium parvum, propagated in laboratory-controlled conditions, were inoculated into 35,000-l volumes of fresh livestock wastes (pig slurries, cattle slurries and dirty waters). D-values for bacteria were six to 44 days, and for C. parvum were 133 to 345 days. Campylobacter jejuni declined significantly more rapidly than the other bacterial pathogens, while E. coli O157 declined significantly more slowly. On average, bacterial declines were not affected by the season of waste deposition and storage or by the dry matter content of the wastes, but were more rapid in dirty waters than in pig slurries. The physiciochemical composition of wastes in each category varied significantly. CONCLUSIONS: Zoonotic agents can survive for several months during storage of liquid livestock wastes. Livestock wastes should be batch-stored and not subjected to continuous additions. SIGNIFICANCE AND IMPACT OF THE STUDY: This study indicates that batches of liquid livestock waste, if contaminated with bacterial pathogens, should be stored for 6 months to reduce contamination levels. Alternative strategies for reducing C. parvum levels in liquid livestock wastes should be explored.     

The effect of temperature on the formation of mutagens in heated beef stock and cooked ground beef

The microsome-activatable mutagens (chromatographically distinguishable from benzo[a]pyrene and from the mutagens produced from pyrolysed amino acids and proteins) previously found in beef extract and in bacterial nutrients which contain beef extract are produced when beef stock is heated. Reflux boiling of beef stock at 100°C results in a linear increase in mutagenic activity toward Salmonella strain TA1538. The rate of production of mutagenic activity at temperatures between 68°C and 98°C conforms closely to the Arrhenius equation, yielding an activation energy of 23 738 calories per mole. Extrapolation from these data predicts a sharp rise in the rate of mutagen formation between 140 and 180°C. This expectation is confirmed when ground beef patties (hamburgers) are prepared in various conventional electrically-heated appliances which operate at different cooking temperatures within this range. The mutagenic activity of hamburger cooked at high temperatures is limited to the surface layers; the temperature of the inside of the hamburger does not exceed 100°C during cooking. No mutagenic activity is found in comparable samples of uncooked meat. The results indicated that the mutagens may be formed as a result of the temperatures encountered in certain conventional cooking procedures.     

Achieving hygiene in the domestic kitchen: the effectiveness of commonly used cleaning procedures

AIMS: To quantify the transmission of Salmonella and Campylobacter to hands, cloths, and hand- and food-contact surfaces during the preparation of raw poultry in domestic kitchens, and to examine the impact on numbers of these bacteria of detergent-based cleaning alone, or in conjunction with thorough rising. METHODS AND RESULTS: Groups of volunteers prepared chickens for cooking. Surfaces were sampled either before cleaning or after cleaning using water and detergent with or without thorough rinsing. Although cleaning followed by rinsing consistently achieved decontamination of surfaces contaminated with Campylobacter, significant numbers of surfaces were still contaminated with low numbers of Salmonella. Where cloths contaminated with Salmonella were stored overnight, a reduction in the efficacy of detergent-based cleaning regimes was observed. CONCLUSIONS: Rinsing is the critical step in ensuring that bacteria are removed from surfaces during cleaning, but this may still leave residual contamination. Growth of Salmonella occurs in some contaminated cloths during overnight storage; Salmonella on cloths stored overnight are also more difficult to remove by washing. SIGNIFICANCE AND IMPACT OF THE STUDY: Rinsing, as part of the cleaning process, is a critical step in achieving hygiene in the kitchen. However, to achieve completely hygienic surfaces, the use of an antimicrobial agent may be necessary.     

<Emphasis Type="BoldItalic">In vitro</Emphasis> availability of some essential minerals in commonly eaten processed and unprocessed Caribbean tuber crops

The levels of three essential minerals Ca, Fe and Mg and the extent of their availability were assessed in four commonly eaten Caribbean tuber crops [dasheen (Xanthosoma spp.), Irish potato (Solanum tuberosum), sweet potato (Ipomoea batatas) and yellow yam (Dioscorea cayenensis)] in their processed and unprocessed states. Calcium was highest in cooked dasheen (5150±50 mg/kg) while Magnesium was highest in uncooked Irish potato (3600±200 mg/kg). There was no significant loss of calcium from the food samples upon cooking. All the uncooked food samples displayed higher levels minerals assessed compared to the cooked samples except for cooked Irish potato that recorded the level of iron (182.25±8.75 mg/kg). Availability of these minerals in the cooked and uncooked tubers crops upon digestion also showed a similar pattern. In conclusion, the consumption of these tuber crops in the Caribbean may not be responsible for the reported cases of iron deficiency in the region. However, the␣availability of minerals from these tuber crops when consumed with other foods (the usual practice in the Caribbean) needs further investigation.     

Tracing of Salmonella spp. in two pork slaughter and cutting plants using serotyping and macrorestriction genotyping

AIMS: The origin of Salmonella contamination of pork products is not well established. In order to further this knowledge, the transmission of Salmonella spp. from live pigs to pork cuts was investigated in two pork slaughter and cutting plants. METHODS AND RESULTS: Salmonella spp. were isolated from both pork (pigs, carcasses, cuts) and the environment before and during slaughterhouse activities. Eight serotypes were identified. XbaI and SpeI macrorestriction distinguished 20 genotypes of Salmonella Typhimurium and 16 genotypes of Salmonella Derby. A major cluster of Salmonella Typhimurium genotypes was common to both plants and all pig-related genotypes, while a predominant pig-related Salmonella Derby genotype was common to both plants. CONCLUSION: None of the Salmonella strains persisted for long periods in the pork-processing environments. SIGNIFICANCE AND IMPACT OF THE STUDY: This work shows that contaminated live pigs, because of bacterial spread due to the process and ineffective cleaning procedures, are involved in Salmonella contamination.     

Occurrence and levels of indicators and selected pathogens in different sludges and biosolids

AIMS: Determine the occurrence and levels of pathogens and indicators in raw and treated sludges and compare their persistence after two different treatments. METHODS AND RESULTS: Helminth ova, Cryptosporidium spp., Salmonella spp., enteroviruses, and bacterial and viral indicators were determined in raw sludges and biosolids produced after mesophilic and thermophilic treatments. Except Salmonella, all of the parameters were quantified. Helminth ova were found at very low concentrations even in raw sludges. Viable Cryptosporidium oocysts were still present in most samples of treated sludges. Faecal coliforms, spores of sulphite-reducing clostridia (SSRC), and somatic coliphages were the only indicators with values above their detection limits in most of the samples. CONCLUSIONS: Pathogens were still detected in some treated sludge samples. SSRC were the most resistant micro-organisms to treatments and hence may be an indicator for the reduction of protozoan oocysts. Somatic coliphages constitute an alternative as viral indicators due to their detection in sludges before and after treatment. SIGNIFICANCE AND IMPACT OF THE STUDY: Because of the persistence of some pathogens after sludge treatments, additional indicators are needed. SSRC and somatic coliphages are good candidates. Easy and inexpensive methods for the determination of these indicators are feasible both in industrialized and developing countries.     

Epidemiological study on Jordanian patients suffering from diarrhoea

Stool specimens from 1400 Diarrhoeal patients from the Jordanian population were examined for bacterial pathogens and Rotavirus during a four- year period (1997-2000). Pathogenic bacteria were identified in 343 patients (24.5%), most often from children. Salmonella spp. was the most frequent isolated organism in 10.7% of the patient's cultures, followed by enteropathogenic Escherichia coli (EPEC) in 3.9%, Shigella spp. in 0.8% and Campylobacter spp. in 0.9%. Vibrio spp. was not identified in the stools tested. Resistance to ampicillin was observed in 42.2% of the Salmonella, 77.0% of the Shigella, and 31.0% of the EPEC isolates. Cotrimoxazole resistance was observed in 34.0% of the Shigella and 13.0% of the EPEC isolates and 77.0% of Campylobacter isolates. Rotavirus was identified in 373 samples (26.6%) of the patients     

Campylobacteriosis, salmonellosis, and shigellosis in free-ranging human-habituated mountain gorillas of Uganda

For conservation purposes and due to growing ecotourism, free-ranging mountain gorillas (Gorilla gorilla beringei) have been habituated to humans. Fecal specimens (n = 62) collected in January 1999 from mountain gorillas of the Bwindi and Mgahinga National Parks, Uganda, were tested for Campylobacter spp., Salmonella spp., and Shigella spp., and the overall prevalence of infection was 19%, 13%, and 6%, respectively. The prevalence of positive specimens was not related to the year of habituation of a gorilla group to humans. Campylobacter spp., Salmonella, and Shigella spp. infections were not distributed equally among the age classes of gorillas; most of the enteropathogens (80%), and all Shigella spp. organisms, S. sonnei, S. boydii, and S. flexneri, were isolated from subadults and adult gorillas with ages ranging from 6.0 to 11.9 yr. The prevalence of Campylobacter spp. and Salmonella spp. infections among human-habituated gorillas has doubled during the last 4 yr, and isolation of Shigella spp. for the first time from mountain gorillas, may indicate enhanced anthropozoonotic transmission of these enteropathogens.     

Campylobacter in chicken livers and their destruction by pan frying

AIM: To enumerate Campylobacter spp. on the external surface and internal portions of chicken livers, and to assess the cooking required to inactivate naturally present cells. METHODS AND RESULTS: Of 30 livers tested all yielded Campylobacter spp. on their surfaces and 90% were found to contain the organism in internal tissue. Four (13%) livers contained >10(4) MPN campylobacters, and an additional seven (23%) contained >10(3) MPN campylobacters per liver. The internal temperature of pan-fried livers under the conditions used reached a maximum of 70-80 degrees C, and maintaining this temperature for 2-3 min was necessary to inactivate naturally occurring Campylobacter spp. All isolates identified were either C. jejuni or C. coli. CONCLUSIONS: Chicken livers represent a potential source of human campylobacteriosis as they contained >10(4) MPN per liver in 13% of the samples tested. Pan-frying can produce an acceptable product that is safe to eat. SIGNIFICANCE AND IMPACT OF THIS STUDY: The data provided can be used in exposure assessments of Campylobacter in poultry products in terms of both quantitative data and assessing pan-frying and its ability to destroy campylobacters.     

Factors affecting the recovery of Campylobacter spp. from retail packs of raw, fresh chicken using ISO 10272-1:2006

Aims:  This study sought to determine the most effective protocol for the detection of Campylobacter spp. in retail packs of fresh, raw chicken based on ISO 10272-1:2006.
Methods and Results:  Three sample preparation protocols were studied; two based on excision and one combining excision with a rinse of the remaining sample. Enrichment cultures were incubated both in closed bottles and microaerobically, and sub-cultured at 24 and 48 h. Packs of chicken (110) were analysed and only two yielded no Campylobacter spp. Subculturing enrichment broths at 24 h gave the same prevalence as at 48 h, P  >   0·4 but microaerobic incubation yielded approximately 50% more positive samples than did incubation in closed bottles. Sampling based on excision plus rinsing gave the highest Campylobacter prevalence (92·7%).
Conclusions:  To isolate Campylobacter spp. from retail packs of chicken, enrichment cultures must be incubated in a microaerobic atmosphere and sub-cultured at 24 h and, possibly, 48 h. Sampling packs by excision plus rinsing maximized recoveries.
Significance and Impact of the Study:  ISO 10272-1:2006 permits the use of inefficient protocols which markedly underestimate the true prevalence of Campylobacter spp. in retail, fresh chicken. Equivalent results could be obtained 24 h earlier, with consequent savings. Its revision is essential.