Karmali Agar Research Articles

Molecular Screening of Kenyan Raw Donkey Milk for the Presence of Pathogenic Microorganisms-Preliminary Risk Analysis

Donkey milk (DM) has attracted a lot of attention in the recent past probably due to its functional properties. It has been viewed as a suitable replacement to cow milk especially for children with cow milk allergies because it has properties similar to human breast milk. While its properties have been studied in most parts of the world, there seem to be no available data on the quality of donkey milk in Kenya. This is despite the fact that the milk has gained popularity amongst the locals as a therapeutic food capable of curing various ailments as per the locals’ claims. The presence of disease-causing organisms is a concern when considering the safety of drinking raw and fermented donkey milk. Hence, the aim of this study was to analyze the microbiological quality specifically focusing on pathogens of raw and fermented donkey milk sampled in Kenya using culture dependent methods and 16S rDNA sequencing. Pooled donkey milk samples were sampled from Nakuru and Naivasha towns in Kenya and transported in cooler box in dry ice to Kiel, Germany for analysis. The presence of pathogenic microorganisms was investigated by laboratory procedures according to the relevant routine protocols (MBT). The samples were analyzed for Total viable counts (TVC) and pathogens. The presence of Salmonella and Shigela spp was tested using Xylose Lysine Deoxycholate (XLD) and Salmonella-Shigela (SS) Agar. Pathogenic non-O157 ShigaToxin-producing E.coli (STEC) presence was tested using CHROMagarTM –STEC. Other Escherichia coli were tested using Tryptone Bile X-Glucuronic (TBX) Agar while Campylobacter spp presence was tested using modified cefoperazone charcoal deoxycholate agar (mCCDA) and Karmali agar. The presence of Listeria spp was tested using ALOA® Oxoid-Chromogenic Listeria agar. Salmonella shigella deoxycholate calcium (SSDC) and Oxoid Yersinia Selective Agar (Schiemann’s CIN Agar) agar was used to detect the presence of pathogenic Yersinia enterolitica. All these spp tested negative in both fresh and fermented DM samples. Our results indicate that donkey milk could be safe microbiologically for consumption and more research is needed to verify the health benefits claims. There is also need to do whole genome analysis to capture the microorganisms that cannot be cultured.

Estimating the performance of four culture media used for enumeration and detection of Campylobacter species in chicken meat

It is well known that culture media used for the detection of foodborne pathogens are imperfect tests and different media present different sensitivity and specificity values. The present study aimed to estimate the performance of four culture media commonly used for enumerating and detecting Campylobacter in foods. Samples of naturally contaminated chicken meat (n = 47) were tested for Campylobacter spp. using in parallel the mCCDA, Karmali agar (KA), CASA® and BCCA, according to ISO 10272:2006 detection and enumeration protocols. Plating onto mCCDA, KA, CASA®, and BCCA produced countable results (>0.9 log cfu/g) in 91.5, 93.2, 95.7 and 95.7% of the samples (enumeration method), but Campylobacter spp. were detected only in 32.6, 36.2, 87.2 and 33.3% of the samples (detection method), respectively. Combined (from all media) pathogen prevalence though was 100 and 87% for enumeration and detection procedures, respectively. Results suggested that CASA® should be considered as a second medium or a suitable alternative of the ISO recommended mCCDA. The single use of mCCDA after enrichment in Bolton broth or after direct plating may lead to erroneous detection of Campylobacter spp. The study also demonstrated that parallel use of the two plating methods improves the recovery of Campylobacter spp.

Comparision of Five Different Enrichment Broth-Agar Combinations for the Isolation of Campylobacter jejuni

Campylobacter is a fastidious microaerophilic bacterium, it is a leading cause of bacterial gastroenteritis in humans globally. In the present study, the efficacy of five enrichment broths in combination with five selective agars for the isolation of Campylobacter jejuni was compared to identify a best possible combination of broth- agar for enrichment. Where, C. jejuni standard culture (ATCC®33560 TM) was enriched in five enrichment broths viz., Brucella, Preston enrichment, modified Charcoal Cefoperazone Deoxycholate broth (mCCDB), Park and Sanders, and Bolton broths, and consequently plated onto modified Charcoal Cefoperazone Deoxycholate agar (mCCDA), Karmali agar, Columbia blood agar, Campylobacter Cefex agar and Campylobacter agar base (CAB). Bolton broth and mCCD agar combination showed the maximum enrichment efficiency and the colony recovery by Bolton broth significantly differed when compared to the Park and Sanders and Brucella broths. The result of the current study shows the combination of enrichment broth and agar most appropriate for the isolation of C. jejuni.

Improvement of Karmali Agar by Supplementation with Tazobactam for Detecting Campylobacter in Raw Poultry

In this study, Karmali agar was modified by adding tazobactam (T-Karmali agar) to suppress the growth of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli , which frequently contaminates raw poultry meat. By inoculating 30 Campylobacter spp. strains and 25 ESBL-producing E. coli strains onto Karmali agar and T-Karmali agar containing various concentrations of the antibacterial agent, we determined the optimum concentration of tazobactam to be 4 mg/liter. The Campylobacter spp. isolation rate on T-Karmali agar (13.3%) was higher than that on Karmali agar (8.3%), although the difference was not significant (P > 0.05). However, T-Karmali agar showed a significantly greater selectivity than Karmali agar, as evaluated by comparing the numbers of contaminated agar plates (20.8 versus 82.5%; P < 0.05) and the growth indexes (1.36 versus 2.83) of competing flora. The predominant competing flora on Karmali and T-Karmali agar were identified as ESBL-producing E. coli . Thus, T-Karmali agar might be effective for determining the real prevalence of Campylobacter in raw poultry and, especially, contamination with ESBL-producing E. coli .

Diagnosis yield of blood agar with filter against karmali agar for isolation of Campylobacter in stool culture

Objetivo: Evaluar el rendimiento diagnostico del agar sangre con filtro (ASF) en comparacion con el agar Karmali (AK) para el diagnostico de Campylobacter spp en coprocultivo.Material y metodos: Se realizo una investigacion de tipo experimental prospectiva de corte transversal en el Hospital Nacional Docente Madre-Nino “San Bartolome” se evaluaron muestra de heces con examen coproloico funcional reactivo para inflamacion. Las muestras fueron sembradas en ASF y en AK e incubadas hasta 72 horas en microaerofilia. La diferenciacio de especies se realizocon la hidrolisis de hipurato.Resultados: Se recolectaron un total de 287 muestra positivas. El aislamiento de Campylobacter en ASF y AK fue de 78,3% y 21,7%, respectivamente. La sensibilidad fue de 90,9% para ASF. El tiempo de crecimiento promedio fue de 32,7 ± 11 horas (p<0,59) y la contaminacio de medios de cultivo de pacientes positivos fue de 61,7% para AK. Se aislaron un 74,8% de especies de Campylobacter no jejuni.Conclusiones: el Agar Sangre con filtro presenta un mayor rendimiento diagnostico que Agar Karmali para el aislamiento de Campylobacter, en un tiempo relativamente menor y demostrando ser mas costo-efectivo que el medio de asilamiento selectivo. Ademas, se aislo principalmente Campylobacter no jejuni en neonatos e infantes, donde acontecen la mayoria de infecciones.

Enterobacterias productoras de Betalactamasas de espectro extendido en muestras fecales en el Instituto Nacional de Salud del Niño, Perú

To describe the frequency of extended-spectrum beta-lactamase (ESBL)-producing enterobacteriaceae in fecal samples at the National Institute of Child Health, Lima, Peru.Stool samples received between July 2012 and March 2013 with colonies suspected to be ESBL-producing enterobacteriaceae that developed in Karmali agar were analyzed. Conventional methods were performed for biochemical identification and the confirmation of the ESBL phenotype. Genotypic analysis to detect the beta-lactamase gene CTX-M family was performed by PCR.Of the 235 fecal samples analyzed, 64.2% of ESBL-producing enterobacteria was isolated being 86.1% Escherichia coli, 7.9% Klebsiella pneumoniae, 2.6% Salmonella sp, 2.0% Enterobacter cloacae, and 1.3% Proteus mirabilis. 89.1% of the ESBL-producing enterobacteria presented the CTX-M gene. We found high resistance to nalidixic acid 84.8%, 74.2% ciprofloxacin and trimethoprim-sulfamethoxazole 81.5%.The resistance to amikacin was 1.3% and all isolates were susceptible to imipenem and meropenem.A high frequency of ESBL-producing enterobacteria was found in fecal samples of outpatients seen in the outpatient and emergency departments of the National Institute of Child Health of Peru.

Modification of Karmali Agar by Supplementation with Potassium Clavulanate for the Isolation of Campylobacter from Chicken Carcass Rinses

The detection ability and selectivity of Karmali agar was improved by supplementation of an extended-spectrum β-lactamase inhibitor, potassium clavulanate. The optimum concentration of potassium clavulanate (0.5 μg/ml) in Karmali agar was determined by inoculation of 50 Campylobacter and 30 extended-spectrum β-lactamase-producing E. coli strains onto normal and modified Karmali agar containing various concentrations of the agent. Eighty retail carcasses were rinsed with 400 ml of buffered peptone water. The rinse samples were enriched in 2× blood-free Bolton enrichment broth at 42°C for 48 h and then were streaked onto normal and modified Karmali agar containing 0.5 μg/ml potassium clavulanate. The suspicious colonies were subcultured on Columbia blood agar and confirmed by colony PCR. In chicken carcass samples, the modified Karmali agar showed a significantly greater isolation rate than normal Karmali agar (42.5 versus 21.3%; P < 0.05). Furthermore, the selectivity of the modified Karmali agar was also significantly higher (P < 0.05) than that of the normal Karmali agar, as seen by comparison of the number of contaminated agar plates (83.8 versus 97.5%) and the growth index (1.67 versus 2.91) of the non-Campylobacter colonies.

Improvement of Karmali Agar by Addition of Polymyxin B for the Detection of Campylobacter jejuni and C. coli in Whole‐Chicken Carcass Rinse

The Karmali agar was modified by supplementation with a high concentration of polymyxin B. The goal of the study was to evaluate the effect of a high concentration of polymyxin B on the ability and selectivity of the modified Karmali agar to isolate Campylobacter jejuni and Campylobacter coli from whole chicken carcass rinse. A total of 80 whole chickens were rinsed with 400 mL of buffer peptone water. The rinsed samples were incubated with 2× blood-free modified Bolton enrichment broth for 48 h, and then streaked onto unmodified Karmali agar and modified Karmali agar supplemented with 100000 IU/L polymixin B (P-Karmali agar). The suspected colonies were finally confirmed by colony PCR. The P-Karmali agar exhibited a significantly better (P < 0.05) isolation rate than the unmodified Karmali agar (P-Karmali agar, 73.8%; unmodified Karmali agar, 33.8%). Moreover, the selectivity of the P-Karmali agar was also better (P < 0.05) than that of the other selective agar when comparing the number of contaminated plates (P-Karmali agar, 68.8%; unmodified Karmali agar, 87.5%) and growth index of competing flora (P-Karmali agar, 1.4; unmodified Karmali agar, 2.7). The improved selective agar excluded competing flora resistant to antibiotic agents in unmodified Karmali agar, increasing isolation rate and selectivity for C. jejuni and C. coli.

Evaluation of the positive predictive value of a rapid Immunochromatographic test to detect Campylobacter in stools

The recently developed rapid immunochromatographic tests (ICT) have the potential to provide a quick and easy diagnosis of Campylobacter enteritis in comparison to culture. In a previous study we found them sensitive but lacking in specificity. The aim of the present study was to focus on the problem of specificity and determine the positive predictive value (PPV) of a positive result of the ImmunoCard Stat! Campy (Meridian Bioscience, Cincinnati, OH, USA). For this purpose, the stools positive by ICT were cultured according to 3 different protocols: Karmali agar, Preston enrichment broth subcultured on Karmali agar, and a filtration method on a blood agar without antibiotics, all incubated for 7 days at 37°C. Out of 609 stools from adults and children with community acquired enteritis, the reference methods detected 25 positive cases (4.1%) (culture: 19, specific PCR and ELISA both positive: 6) and the ICT: 31 including the 25 true positives. The PPV was 80.6%. We conclude that ICT is a good method to screen Campylobacter positive stools but because of its lack of specificity the positive stools must be tested by another method.

Distribution and Genotypic Characterization of Campylobacter jejuni Isolated from Poultry in Split and Dalmatia County, Croatia

Consumption of poultry contaminated with Campylobacter jejuni has been recognized worldwide as the leading cause of campylobacteriosis. Therefore, the aim of our study was to investigate the prevalence and genotype diversity of Campylobacter jejuni in poultry meat intended for consumption in Split and Dalmatia County, which is the second biggest County in Croatia. Furthermore, we also wanted to discover possibly stable clones of C.jejuni appearing in different samples and periods of time, which would indicate their ability to persist in or adapt to poultry. In the period from March 2008 until June 2010, 834 samples of poultry from various sources were examined using a surface swab technique. Isolation of C.jejuni was performed by Preston broth and Karmali agar. Identification of the isolates was carried out using biochemical tests. C.jejuni was found in 84 of 574 chicken samples (14.6%) and in nine of 260 samples of turkey (3.5%). Pulse-field gel electrophoresis (PFGE) was used to analyse 61 obtained isolates using SmaI and KpnI. Of 22 different macrorestriction profiles (MRP) that were found, five were detected in poultry from both different locations and periods of time. Samples from 11 locations were found to be contaminated with more than two different genotypes of C.jejuni. Interestingly, the same MRP were found both in poultry declared to be of domestic origin and in the poultry imported from abroad. The prevalence of C.jejuni in poultry samples was in accordance with previously reported results. Genotypic analysis indicated that the population of C.jejuni in Split and Dalmatia County was diverse and that multiple strains of C.jejuni could be found in the same poultry samples. Furthermore, the same genotypes were identified from the samples obtained from different locations and periods of time, which could support the theory of a global existence of certain MRP that are able to persist in or adapt to poultry.

Possibility of Campylobacter jejuni inactivation in smoked salmon by high-pressure treatment

The sterile samples of cold-smoked salmon were placed in polyamide–polyethylene pouches and inoculated with three-strain composite of Campylobacter jejuni (inoculum ca 107 CFU g−1). The inoculated samples were sealed under vacuum and subjected to 200, 300 and 400 MPa of hydrostatic pressure for 0, 5, 10 and 15 min. The number of surviving C. jejuni per gram was determined by the 10-fold dilution method followed by plating on Karmali agar. D 10 values were calculated. This work has shown that for reducing C. jejuni in cold-smoked salmon by 6 log units, the application of 200 MPa for 64.26 min or 300 MPa for 17.10 min or 400 MPa for less than 5 min is needed. Applying such parameters of high-pressure processing should not change significantly the organoleptic properties of the product.

Presence of thermophilic Campylobacter species in Broilers and pigs at certain abattoirs in Republic of Serbia

Examinations were carried out during the period from January 2006 until March 2007 on a total of 449 samples of the cecum of broilers and the cecum and the colon of pigs. These samples included 251 samples originating from broilers and 198 samples of pig cecums and colons. All the listed samples were obtained by scraping the surface of these parts of the digestive system of broilers and pigs. At the site of sampling, the diluted material was sown on a medium (Karmali agar), in order to get individual colonies. After sowing, the bases were placed in anaerobic jars in which microaerophilic conditions were achieved using Campy Pak, BBL bags. On arrival at the laboratory, the jars containing the sown bases were placed in a thermostat, at a temperature of 42oC for 48 hours for the purpose of incubation. Following incubation, the grown colonies were examined macroscopically, and then microscopic preparations were made from them, which were stained with 2% carbol fuchsin after drying and fixation. Those isolates which were in the form of a comma, the letter S, or gull's wings in the microscopic preparations were considered Campylobacter species (Figures 1 and 2). The isolated thermophilic campylobacteria were identified using conventional and commercial biochemical tests API Campy, manufactured by Bio M?rieux, France. With the application of these microbiological methods, thermophilic Campylobacter species were isolated from 203 (80.88%) of the 251 samples of broiler cecums. Furthermore, thermophilic campylobacteria were isolated from 153 (77.27%) of the 198 samples from the cecum and colon of pigs taken within these investigations. The obtained results indicate that there is a somewhat greater prevalence of these bacteria among the broilers. However, such a high percentage of both broilers and pigs colonized by thermophilic Campylobacter species could pose a serious problem, in particular when it is known that infections of humans caused by the consumption of insufficiently thermally processed meat of broilers or pigs are not infrequent.

Commonality and Biosynthesis of the O-Methyl Phosphoramidate Capsule Modification in Campylobacter jejuni

In this study we investigated the commonality and biosynthesis of the O-methyl phosphoramidate (MeOPN) group found on the capsular polysaccharide (CPS) of Campylobacter jejuni. High resolution magic angle spinning NMR spectroscopy was used as a rapid, high throughput means to examine multiple isolates, analyze the cecal contents of colonized chickens, and screen a library of CPS mutants for the presence of MeOPN. Sixty eight percent of C. jejuni strains were found to express the MeOPN with a high prevalence among isolates from enteritis, Guillain Barré, and Miller-Fisher syndrome patients. In contrast, MeOPN was not observed for any of the Campylobacter coli strains examined. The MeOPN was detected on C. jejuni retrieved from cecal contents of colonized chickens demonstrating that the modification is expressed by bacteria inhabiting the avian gastrointestinal tract. In C. jejuni 11168H, the cj1415-cj1418 cluster was shown to be involved in the biosynthesis of MeOPN. Genetic complementation studies and NMR/mass spectrometric analyses of CPS from this strain also revealed that cj1421 and cj1422 encode MeOPN transferases. Cj1421 adds the MeOPN to C-3 of the beta-d-GalfNAc residue, whereas Cj1422 transfers the MeOPN to C-4 of D-glycero-alpha-L-gluco-heptopyranose. CPS produced by the 11168H strain was found to be extensively modified with variable MeOPN, methyl, ethanolamine, and N-glycerol groups. These findings establish the importance of the MeOPN as a diagnostic marker and therapeutic target for C. jejuni and set the groundwork for future studies aimed at the detailed elucidation of the MeOPN biosynthetic pathway.

Performance characteristics and estimation of measurement uncertainty of three plating procedures for Campylobacter enumeration in chicken meat

In this work, we present an intra-laboratory study in order to estimate repeatability ( r), reproducibility ( R), and measurement uncertainty ( U) associated with three media for Campylobacter enumeration, named, modified charcoal cefoperazone deoxycholate agar (mCCDA); Karmali agar; and CampyFood ID agar (CFA) a medium by Biomérieux ® SA. The study was performed at three levels: (1) pure bacterial cultures, using three Campylobacter strains; (2) artificially contaminated samples from three chicken meat matrixes (total n=30), whereby samples were spiked using two contamination levels; ca. 10 3 cfu Campylobacter/g, and ca. 10 4 cfu Campylobacter/g; and (3) pilot testing in naturally contaminated chicken meat samples ( n=20). Results from pure culture experiment revealed that enumeration of Campylobacter colonies on Karmali and CFA media was more convenient in comparison with mCCDA using spread and spiral plating techniques. Based on artificially contaminated samples testing, values of repeatability ( r) were comparable between the three media, and estimated as 0.15 log 10 cfu/g for mCCDA, 0.14 log 10 cfu/g for Karmali, and 0.18 log 10 cfu/g for CFA. As well, reproducibility performance of the three plating media was comparable. General R values which can be used when testing chicken meat samples are; 0.28 log 10, 0.32 log 10, and 0.25 log 10 for plating on mCCDA, Karmali agar, and CFA, respectively. Measurement uncertainty associated with mCCDA, Karmali agar, and CFA using spread plating, for combination of all meat matrixes, were ±0.24 log 10 cfu/g, ±0.28 log 10 cfu/g, and ±0.22 log 10 cfu/g, respectively. Higher uncertainty was associated with Karmali agar for Campylobacter enumeration in artificially inoculated minced meat (±0.48 log 10 cfu/g). The general performance of CFA medium was comparable with mCCDA performance at the level of artificially contaminated samples. However, when tested at naturally contaminated samples, non- Campylobacter colonies gave similar deep red colour as that given by the typical Campylobacter growth on CFA. Such colonies were not easily distinguishable by naked eye. In general, the overall reproducibility, repeatability, and measurement uncertainty estimated by our study indicate that there are no major problems with the precision of the International Organization for Standardization (ISO) 10272-2:2006 protocol for Campylobacter enumeration using mCCDA medium.

Quantification of Campylobacter Species Cross-Contamination during Handling of Contaminated Fresh Chicken Parts in Kitchens

Numerous outbreak investigations and case-control studies for campylobacteriosis have provided evidence that handling Campylobacter-contaminated chicken products is a risk factor for infection and illness. There is currently extremely limited quantitative data on the levels of Campylobacter cross-contamination in the kitchen, hindering risk assessments for the pathogen commodity combination of Campylobacter and chicken meat. An exposure assessment needs to quantify the transfer of the bacteria from chicken to hands and the kitchen environment and from there onto ready-to-eat foods. We simulated some typical situations in kitchens and quantified the Campylobacter transfer from naturally contaminated chicken parts most commonly used in Germany. One scenario simulated the seasoning of five chicken legs and the reuse of the same plate for cooked meat. In another, five chicken breast filets were cut into small slices on a wooden board where, without intermediate cleaning, a cucumber was sliced. We also investigated the transfer of the pathogen from chicken via hands to a bread roll. The numbers of Campylobacter present on the surfaces of the chicken parts, hands, utensils, and ready-to-eat foods were detected by using Preston enrichment and colony counting after surface plating on Karmali agar. The mean transfer rates from legs and filets to hands were 2.9 and 3.8%. The transfer from legs to the plate (0.3%) was significantly smaller (P < 0.01) than the percentage transferred from filets to the cutting board and knife (1.1%). Average transfer rates from hands or kitchen utensils to ready-to-eat foods ranged from 2.9 to 27.5%.

Survival of Campylobacter jejuni strains of different origin in drinking water.

The aim of the study was to measure the survival of 19 Campylobacter jejuni strains of different origins, including two reference strains, four poultry-derived isolates, nine human isolates and four water isolates, in sterilized drinking water. Pure cultures of 19 C. jejuni strains were inoculated in sterile drinking water and incubated at 4 degrees C for 64 days. Survival was determined by culturability on both selective (Karmali agar) and non-selective [Columbia blood agar (CBA)] media. Culturability was shown to be strain and origin-dependent. Campylobacter jejuni showed prolonged survival on a non-selective than on a selective medium. The origin of the strain is a determining factor for the survival of C. jejuni in drinking water at 4 degrees C. Poultry isolates showed a prolonged survival, which could be an indication that these strains could play an important role in the transmission of campylobacteriosis through water. In addition, culture conditions are an important factor for evaluating the survival of C. jejuni in drinking water at 4 degrees C. The non-selective agar (CBA) allowed growth of C. jejuni over a longer period of time than the selective agar (Karmali). Furthermore, an enrichment broth (Bolton) allowed the recovery of all 19 C. jejuni strains during the 64 days of incubation at 4 degrees C. This study highlighted differences in culturability depending on culture conditions and on strain origin.

Immunomagnetic separation methods for the isolation of Campylobacter jejuni from ground poultry meats

Campylobacter jejuni is now recognized as a leading foodborne pathogen, for which poultry products constitute the main transmission route. Two alternative immunomagnetic beads (IMB) were tested for direct detection of C. jejuni ATCC 35918 in artificially inoculated ground poultry meats and culture suspension. Polyclonal anti- Campylobacter antibodies were used to coat tosylactivated Dynabeads. The same antibodies conjugated with biotin were used to label streptavidin-coated beads. After these beads were incubated with inoculated poultry slurry or culture suspension, Campylobacter-bead complexes were separated from other components with a magnet. The capture efficiency was tested by plating bead-captured cells and unbound cells in the supernatant onto Karmali agar. The effects of different coating procedures, incubation time (60, 90, 120 min), numbers of immunomagnetic beads (10 6 to 10 7/ml) and innoculum levels (10 3 to 10 7 CFU/g or ml) were determined. Without pre-enrichment, this approach could detect 10 4 CFU/g of ground poultry meats. These methods represent a new approach to extracting, concentrating and isolating Campylobacter spp. directly from foods.

Incidence of thermotolerantCampylobacterin foods assessed by NF ISO 10272 standard: results of a two-year study

Fifteen hundred food samples were analysed for thermotolerantCampylobacteraccording to the NF ISO 10272 standard during a two-year investigation period using Preston and Park & Sanders methods and three isolation media (Karmali, Butzler and Skirrow agar). The samples, consisting of 660 oysters(Crassostrea gigas), 400 ready-to-eat vegetables, 300 poultry products and 140 raw milk cheeses, were positive 5, 2, 12 and 0 times respectively. All isolates were identified asCampylobacter jejunisubsp.jejuniexcept oneC. coli.Biotype and serotype determination revealed a large diversity among the strains, although biotypes I (59%) and II (18%) were predominant. Serotyping (Lior scheme) showed that 85% of the strains were among the 10 most common Campylobacter serogroups isolated in human campylobacteriosis. Park & Sanders enrichment and isolation on Karmali agar appeared to be the most efficient combination for detecting thermotolerant Campylobacter in the food samples tested.

The isolation and prevalence of campylobacters from dairy cattle using a variety of methods.

Faecal samples from 94 dairy cows and 42 calves in three different herds were examined by a variety of techniques for campylobacters. Cefoperazone amphotericin teicoplanin (CAT) agar, modified cefoperazone charcoal deoxycholate agar (mCCDA), Karmali agar, and membrane filtration onto blood agar, were used with and without enrichment in CAT broth. Seventy-nine percent of cattle in herd A carried campylobacters, compared with 40% and 37.5% of cattle in herds B and C, respectively. Most animals carried only one species of Campylobacter. Campylobacter hyointestinalis was isolated most frequently (32% animals positive) with Camp. fetus subsp. fetus and Camp. jejuni subsp. jejuni detected in 11% and 7% of animals, respectively. In addition, a novel biotype of Camp. sputorum was isolated from 60% of 47 cows tested in herd A. Direct plating detected only two of the total of 40 animals positive for campylobacter. Enrichment in CAT broth before membrane filtration onto blood agar or CAT agar were the most successful methods of plating. Campylobacter sputorum was isolated from CAT agar and blood agar but not from mCCDA or Karmali agar. Karmali agar incubated at 30 degrees C was especially effective for isolating Camp. fetus subsp. fetus.