Prevalence of Campylobacter in infant, juvenile and adult laboratory primates

A cross-sectional study of Campylobacter spp. infection was conducted on 125 infant (Macaca nemestrina and Macaca fascicularis) in an infant primate nursery housing infants from birth to 18 months of age, and 145 M. nemestrina aged from 4 months to 15 years at another facility (Primate Field Station) housing animals from birth to aged adults. The objective was to determine the prevalence of Campylobacter spp. in various age groups and to investigate the correlation with diarrhea. In the Infant Primate Research Laboratory approximately 70% of infants were infected at 18 months-old. Campylobacter coli was isolated from approximately two-thirds of the infected infants. One-third were Campylobacter jejuni and occasional infants were infected with a naladixic acid resistant, hippurate negative (NAR) Campylobacter spp. At the Primate Field Station virtually all animals cultured in 4-6 month-old, 16-20 month-old, and 3-5 year-old age groups were positive. Approximately one-third of middle-aged adults (10-15 years old) were positive with C. coli or NAR Campylobacter spp. Environmental factors such as location and movement of animals may provide an explanation for the prevalence data obtained in the two facilities and different age groups of animals. An etiologic role of Campylobacter spp. in diarrhea of laboratory primates was not established in this study.     

Development of real-time PCR and hybridization methods for detection and identification of thermophilic Campylobacter spp. in pig faecal samples

AIMS: To develop a real-time (rt) PCR for species differentiation of thermophilic Campylobacter and to develop a method for assessing co-colonization of pigs by Campylobacter spp. METHODS AND RESULTS: The specificity of a developed 5' nuclease rt-PCR for species-specific identification of Campylobacter jejuni, Campylobacter coli, Campylobacter lari, Campylobacter upsaliensis and of a hipO gene nucleotide probe for detection of C. jejuni by colony-blot hybridization were determined by testing a total of 75 reference strains of Campylobacter spp. and related organisms. The rt-PCR method allowed species-specific detection of Campylobacter spp. in naturally infected pig faecal samples after an enrichment step, whereas the hybridization approach enhanced the specific isolation of C. jejuni (present in minority to C. coli) from pigs. Conclusions: The rt-PCR was specific for Campylobacter jejuni, C. coli, C. lari, and C. upsaliensis and the colony-blot hybridization approach provided an effective tool for isolation of C. jejuni from pig faecal samples typically dominated by C. coli. SIGNIFICANCE AND IMPACT OF THE STUDY: Species differentiation between thermophilic Campylobacter is difficult by phenotypic methods and the developed rt-PCR provides an easy and fast method for such differentiation. Detection of C. jejuni by colony hybridization may increase the isolation rate of this species from pig faeces.     

Emerging dynamics of human campylobacteriosis in Southern Ireland

Infections with Campylobacter spp. pose a significant health burden worldwide. The significance of Campylobacter jejuni/Campylobacter coli infection is well appreciated but the contribution of non-C. jejuni/C. coli spp. to human gastroenteritis is largely unknown. In this study, we employed a two-tiered molecular study on 7194 patient faecal samples received by the Microbiology Department in Cork University Hospital during 2009. The first step, using EntericBio(?) (Serosep), a multiplex PCR system, detected Campylobacter to the genus level. The second step, utilizing Campylobacter species-specific PCR identified to the species level. A total of 340 samples were confirmed as Campylobacter genus positive, 329 of which were identified to species level with 33 samples containing mixed Campylobacter infections. Campylobacter jejuni, present in 72.4% of samples, was the most common species detected, however, 27.4% of patient samples contained non-C. jejuni/C. coli spp.; Campylobacter fetus (2.4%), Campylobacter upsaliensis (1.2%), Campylobacter hyointestinalis (1.5%), Campylobacter lari (0.6%) and an emerging species, Campylobacter ureolyticus (24.4%). We report a prominent seasonal distribution for campylobacteriosis (Spring), with C. ureolyticus (March) preceeding slightly C. jejuni/C. coli (April/May).     

Detection of cytolethal distending toxin activity and cdt genes in Campylobacter spp. isolated from chicken carcasses

This study was designed to determine whether isolates from chicken carcasses, the primary source of Campylobacter jejuni and Campylobacter coli in human infections, commonly carry the cdt genes and also whether active cytolethal distending toxin (CDT) is produced by these isolates. Campylobacter spp. were isolated from all 91 fresh chicken carcasses purchased from local supermarkets. Campylobacter spp. were identified on the basis of both biochemical and PCR tests. Of the 105 isolates, 70 (67%) were identified as C. jejuni, and 35 (33%) were identified as C. coli. PCR tests amplified portions of the cdt genes from all 105 isolates. Restriction analysis of PCR products indicated that there appeared to be species-specific differences between the C. jejuni and C. coli cdt genes, but that the restriction patterns of the cdt genes within strains of the same species were almost invariant. Quantitation of active CDT levels produced by the isolates indicated that all C. jejuni strains except four (94%) had mean CDT titers greater than 100. Only one C. jejuni strain appeared to produce no active CDT. C. coli isolates produced little or no toxin. These results confirm the high rate of Campylobacter sp. contamination of fresh chicken carcasses and indicate that cdt genes may be universally present in C. jejuni and C. coli isolates from chicken carcasses.     

Prevalence and genetic diversity of Campylobacter spp. in environmental water samples from a 100-square-kilometer predominantly dairy farming area

Water samples were taken systematically from a 100-km2 area of mainly dairy farmland in northwestern England and examined for Campylobacter spp. Pulsed-field gel electrophoresis-restriction fragment length polymorphism (PFGE-RFLP) and flaA strain typing of Campylobacter jejuni and Campylobacter coli isolates were done. Data on the water source and the adjacent environment were recorded and examined as explanatory variables. Campylobacter spp. were isolated from 40.5% (n = 119) of the water samples tested. C. jejuni was isolated from 14.3%, C. coli was isolated from 18.5%, and Campylobacter lari was isolated from 4.2% of the samples. Campylobacter hyointestinalis was not isolated from any water source. The difference in prevalence between water types (trough, running, and standing) was significant (P = 0.001). C. jejuni was the species most commonly isolated from trough-water and running-water sources, while C. coli was the most frequently isolated from standing water (P < 0.001). No association was found between the presence of Escherichia coli and that of Campylobacter spp. The final multivariable logistic regression model for Campylobacter spp. included the following variables: water source, soil type, aspect, and amount of cattle fecal material in the environment (fecal pat count). Strain typing demonstrated a diverse population of C. jejuni and the presence of a common C. coli flaA type that was widely distributed throughout the area. Most of the isolates within the common flaA type were discriminated by PFGE-RFLP. These findings suggest a possible role for environmental water in the epidemiology of Campylobacter spp. in a farming environment.     

Prevalence of Campylobacter jejuni,Campylobacter lari,and Campylobacter coli in different ecological guilds and taxa of migrating birds

A total of 1,794 migrating birds trapped at a coastal site in southern Sweden were sampled for detection of Campylobacter spp. All isolates phenotypically identified as Campylobacter jejuni and a subset of those identified as non-C. jejuni were identified to the species level by PCR-based techniques. C. jejuni was found in 5.0% of the birds, Campylobacter lari was found in 5.6%, and Campylobacter coli was found in 0.9%. An additional 10.7% of the tested birds were infected with hippurate hydrolysis-negative Campylobacter spp. that were not identified to the species level. The prevalence of Campylobacter spp. differed significantly between ecological guilds of birds. Shoreline-foraging birds feeding on invertebrates and opportunistic feeders were most commonly infected (76.8 and 50.0%, respectively). High prevalence was also shown in other ground-foraging guilds, i.e., ground-foraging invertebrate feeders (11.0%), ground-foraging insectivores (20.3%), and plant-eating species (18.8%). Almost no Campylobacter spp. were found in ground-foraging granivores (2.3%), arboreal insectivores (0.6%), aerial insectivores (0%), or reed- and herbaceous plant-foraging insectivores (3.5%). During the autumn migration, a high proportion of samples from juveniles were positive (7.1% in passerines, 55.0% in shorebirds), indicating transmission on the breeding grounds or during the early part of migration. Prevalence of Campylobacter spp. was associated with increasing body mass among passerine bird species. Furthermore, prevalence was higher in short-distance migrants wintering in Europe than in long-distance migrants wintering in Africa, the Middle East, or Asia. Among ground-foraging birds of the Muscicapidae, those of the subfamily Turdinae (i.e., Turdus spp.) showed a high prevalence of Campylobacter spp., while the organism was not isolated in any member of the subfamily Muscicapinae (i.e., Erithacus and Luscinia). The prevalence of Campylobacter infection in wild birds thus seems to be linked to various ecological and phylogenetic factors, with great variations in carriership between different taxa and guilds.     

Prevalence and antimicrobial resistance of thermophilic Campylobacter spp. from cattle farms in Washington State

The prevalence of thermophilic Campylobacter spp. was investigated in cattle on Washington State farms. A total of 350 thermophilic Campylobacter isolates were isolated from 686 cattle sampled on 15 farms (eight dairies, two calf rearer farms, two feedlots, and three beef cow-calf ranches). Isolate species were identified with a combination of phenotypic tests, hipO colony blot hybridization, and multiplex lpxA PCR. Breakpoint resistance to four antimicrobials (ciprofloxacin, nalidixic acid, erythromycin, and doxycycline) was determined by agar dilution. Campylobacter jejuni was the most frequent species isolated (34.1%), followed by Campylobacter coli (7.7%) and other thermophilic campylobacters (1.5%). The most frequently detected resistance was to doxycycline (42.3% of 350 isolates). Isolates from calf rearer facilities were more frequently doxycycline resistant than isolates from other farm types. C. jejuni was most frequently susceptible to all four of the antimicrobial drugs studied (58.8% of 272 isolates). C. coli isolates were more frequently resistant than C. jejuni, including resistance to quinolone antimicrobials (89.3% of isolates obtained from calves on calf rearer farms) and to erythromycin (72.2% of isolates obtained from feedlot cattle). Multiple drug resistance was more frequent in C. coli (51.5%) than in C. jejuni (5.1%). The results of this study demonstrate that C. jejuni is widely distributed among Washington cattle farms, while C. coli is more narrowly distributed but significantly more resistant.     

Prevalence of putative virulence markers in Campylobacter jejuni and Campylobacter coli isolated from hospitalized children, raw chicken, and raw beef in Tehran, Iran

The incidence of the virulence-associated genes cdtA, cdtB, cdtC, cadF, dnaJ, racR, and pldA has been investigated in Campylobacter jejuni and Campylobacter coli collected from raw chicken and beef from retailers in Tehran, Iran, and from hospitalized children (age, ≤14 years) suffering from diarrhea. Campylobacter spp. were collectively identified by morphological and biochemical methods. Campylobacter jejuni and C. coli were discriminated from other Campylobacter spp. by amplification of a specific conserved fragment of the 16S rRNA gene. The distinction between C. jejuni and C. coli was subsequently made by molecular determination of the presence of the hipO gene in C. jejuni or the ask gene in C. coli. Fragments of the studied virulence-associated genes, cdtA, cdtB, cdtC, cadF, racR, dnaJ, and pldA, were amplified by PCR and subjected to horizontal gel electrophoresis. A total of 71 isolates of C. jejuni and 24 isolates of C. coli from meat were analyzed, while the numbers of isolates from the hospitalized children were 28 and 9, respectively. The unequal distribution of C. jejuni and C. coli in the samples has also been reported in other studies. Statistical analyses by the use of the two-tailed Fisher's exact test of the occurrence of the virulence genes in the isolates of different origins showed that the occurrence of the dnaJ gene was consistently significantly higher in all C. jejuni isolates than in C. coli. The occurrence of the other virulence markers did not differ significantly between species in the majority of the isolates. The PCR results also showed that the occurrence of the virulence markers in the analyzed isolates was much lower than in other studies, which may be caused by a divergent genomic pool of our isolates in comparison with others.     

Antimicrobial susceptibilities of Campylobacter sp strains isolated from humans in 2005 to 2006 in Bielsko-Biala Region, Poland

Campylobacter jejuni and Campylobacter coli are frequent causes of bacterial gastroeneritis in humans worldwide. Campylobacteriois is usually a self-limiting disease and therapy with antibiotics is required in severe clinical infections. The objective [corrected] of this study was to determine the antibiotic resistance of C. jejuni and C. coli isolated from humans with diarrhea during 2005-2006 in Bielsko-Biala region in Poland. The MICs of ciprofloxacin, tetracycline, erythromycin, gentamicin and ampicillin were determined by the E-test method. It was observed that 23 % and 6% C. jejuni isolates were resistant to two and three antibiotics, respectively. All isolates of Campylobacter sp. were sensitive to erythromycin and gentamicin. From the 69 C. jejuni strains 58% were resistant to ciprofloxacin, 23% to tetracycline and 17% to ampicillin. From the 8 C. coli strains all were resistant to ciprofloxacin, 62,5% to ampicillin and 12,5% to tetracycline.     

A laboratory-based survey of Campylobacter infections in Prahova County

In developing countries, as well as in many western countries, members of the genus Campylobacter are recognized as one of the most common cause of acute bacterial enteritis. Campylobacter jejuni and Campylobacter coli isolation rates have been shown to be equal to, and sometimes higher than those of other enteric pathogens. The Microbiology Laboratory of the local Public Health Authority in Prahova County conducted a one and a half-year laboratory-based survey of Campylobacter infections in patients suffering from gastrointestinal symptoms. From a total of 3284 stool samples screened, the culture-positive ones confirmed the bacterial etiology for 551 diarrhea cases. Campylobacter was found in 345 specimens, being the most frequently isolated enteropathogen. C. jejuni outnumbered C. coli species (239 vs. 106 isolates). Salmonella isolates were the second local cause of diarrhea. The highest isolation rate of Campylobacter was found in children 5 years of age (262 strains). The prevalence of campylobacteriosis declined with age. The isolation rate of Campylobacter (10.5%), the unimodal age-specific distribution of cases, as well as the identification of polymicrobial infections among the screened population were epidemiological aspects resembling reports on campylobacteriosis in developing countries. The susceptibility of Campylobacter isolates to various antimicrobial agents, including macrolides and fluoroquinolones was also assessed. Among the screened isolates, Erythromycin retained a good activity, while an increased ciprofloxacin resistance was observed. The information gathered through this local study sustains the importance of Campylobacter in the etiology of autochthonous infectious diarrhea. A development of a national surveillance program regarding the most important foodborne pathogens would be beneficial for improving prevention and controlling measures.     

Biochemical and serologic characteristics of Campylobacter jejuni/coli strains causing diarrhea in children

One hundred strains of Campylobacter jejuni/coli isolated from faeces of children with diarrhoea were characterised. Frequency of isolation of these microorganisms from faeces of children with enterocolitis symptoms was evaluated. In this group Campylobacter jejuni/coli constituted 11.4% of all isolates, being the dominant etiologic agent of these infections. Biotype pattern of 100 Campylobacter jejuni/coli strains was determined. Biotype I C.jejuni prevailed and C. coli constituted as much as 35% of all isolated strains. All isolated strains were characterised serologically according to typing scheme of Lior. Seventy four strains were typed and 22 were untypable, out of which four were rough. Two new serotypes were isolated: LIO 71 and LIO 72, LIO 4 and LIO 72 serotypes were the most frequently isolated. Frequency of isolation of Campylobacter jejuni/coli strains were also determined in the period from january 1985 to august 1987.     

Antibiotic resistance and resistance mechanisms in Campylobacter jejuni and Campylobacter coli

Campylobacter jejuni and Campylobacter coli are recognized as the most common causative agents of bacterial gastroenteritis in the world and infections with these organisms occur more frequently than do infections due to Salmonella species, Shigella species, or Escherichia coli 0157:H7. The incidence of human Campylobacter infections has increased markedly in both developed and developing countries worldwide and, more significantly, so has the rapid emergence of antibiotic-resistant Campylobacter strains, with evidence suggesting that the use of antibiotics, in particular the fluoroquinolones, as growth promoters in food animals and the veterinary industry is accelerating this trend. In this minireview, the patterns of emerging resistance to the antimicrobial agents useful in treatment of the disease are presented and the mechanisms of resistance to these drugs in Campylobacter spp are discussed.     

Prevalence and antimicrobial resistance of Campylobacter in US dairy cattle

AIMS: To obtain an overview of the prevalence and antimicrobial resistance of Campylobacter in faeces of US dairy cows in 2002. METHODS AND RESULTS: Faeces from 1435 cows, representing 96 dairy operations in 21 US states, were collected for the culture of Campylobacter. A total of 735 Campylobacter strains were isolated (51.2% positive samples) with 94 operations positive (97.9%) for Campylobacter. From this collection, 532 isolates (473 Campylobacter jejuni and 59 Campylobacter coli) were randomly selected for susceptibility testing to eight antimicrobials: azithromycin, chloramphenicol, ciprofloxacin, clindamycin, erythromycin, gentamicin, nalidixic acid and tetracycline. The C. jejuni isolates exhibited resistance to tetracycline (47.4%), nalidixic acid (4.0%) and ciprofloxacin (2.5%), while the C. coli strains exhibited some resistance to all antimicrobials except chloramphenicol and ciprofloxacin. Only 3.6% of the C. jejuni isolates were resistant to two or more antimicrobials but 20.3% of the C. coli strains were multiresistant. CONCLUSIONS: On most operations, at least one cow was positive for Campylobacter and more than half of the cows sampled were shedding Campylobacter. The C. coli isolates had significantly higher levels of resistance to macrolides and to tetracycline compared with the C. jejuni strains, but were susceptible to ciprofloxacin. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrated a high prevalence of Campylobacter on US dairy operations; however, US dairy cattle have not been recognized as a major source of human infection compared with poultry. Campylobacter coli appears to develop antimicrobial resistance more readily than C. jejuni from the same environment.     

Development of a novel triplex PCR assay for the detection and differentiation of thermophilic species of Campylobacter using 16S-23S rDNA internal transcribed spacer (ITS) region

AIM: Campylobacter species are significantly implicated in human gastrointestinal infections. Of 20 species of Campylobacter, C. jejuni, C. coli and C. lari have been considered as the most important causative agents of human infections. In order to better understand the occurrence and epidemiology of these thermophilic Campylobacter species, an improved and rapid detection method is warranted. A novel triplex polymerase chain reaction (PCR) assay was developed based on the variable 16S-23S rDNA internal transcribed spacer (ITS) region to identify and discriminate between these species in water samples. METHODS AND RESULTS: Campylobacter species-specific primers for C. jejuni, C. coli and C. lari derived from highly variable sequences in the ITS region were used. Specificity of the newly designed primers and PCR conditions were verified using other species of Campylobacter as well as 31 different negative control species. The assay was further validated with 97 Campylobacter cultures from water samples. CONCLUSIONS: The assay was found to be simple, easy to perform, and had a high sensitivity, specificity and reproducibility. It enabled simultaneous detection and differentiation of multiple Campylobacter species in water samples. SIGNIFICANCE AND IMPACT OF STUDY: Use of the newly developed PCR assay, coupled with a previously developed rapid DNA template preparation step, will enable improved detection capabilities for Campylobacter species in environmental matrices.     

Prevalence of Campylobacter spp. in skinless, boneless retail broiler meat from 2005 through 2011 in Alabama, USA

ABSTRACT: BACKGROUND: The prevalence of Campylobacter spp. in 755 skinless, boneless retail broiler meat samples (breast, tenderloins and thighs) collected from food stores in Alabama, USA, from 2005 through 2011 was examined. Campylobacter spp. were isolated using enrichment and plate media. Isolates were identified with multiplex PCR assays and typed with pulsed field gel electrophoresis (PFGE). Data were analyzed by nominal variables (brand, plant, product, season, state and store) that may affect the prevalence of these bacteria. RESULTS: The average prevalence of Campylobacter spp. in retail broiler meat for these years was 41%, with no statistical differences in the prevalence by year (P > 0.05). Seasons did not affect the prevalence of C. jejuni but statistically affected the prevalence of C. coli (P < 0.05). The prevalence by brand, plant, product, state and store were different (P < 0.05). Establishments from two states had the highest prevalence (P < 0.05). C. coli and C. jejuni had an average prevalence of 28% and 66%, respectively. The prevalence of C. coli varied by brand, plant, season, state, store and year, while the prevalence of C. jejuni varied by brand, product, state and store. Tenderloins had a lower prevalence of Campylobacter spp. than breasts and thighs (P < 0.05). Although no statistical differences (P > 0.05) were observed in the prevalence of C. jejuni by season, the lowest prevalence of C. coli was recorded from October through March. A large diversity of PFGE profiles was found for C. jejuni, with some profiles from the same processing plants reappearing throughout the years. CONCLUSIONS: The prevalence of Campylobacter spp. did not change during the seven years of the study; however, it did change when analyzed by brand, product and state. Seasons did not affect the prevalence of C. jejuni, but they did affect the prevalence of C. coli. Larger PFGE databases are needed to assess the temporal reoccurrence of PFGE profiles to help predict the risk associated with each profile.     

Small rodents and other mammals associated with mountain meadows as reservoirs of Giardia spp. and Campylobacter spp

Sixty-five percent (469 of 722) of the fecal samples collected from small rodents in the central Washington Cascade mountains were positive for Giardia spp. Trapping studies showed that microtines of the genus Microtus were heavily infected with the parasite. Morphologically the cysts and trophozoites were of the Giardia duodenalis type. Small-rodent populations appear to maintain their infection throughout the year. Our data suggest that there is no difference in the percentage of positive animals in areas receiving a lot of human use as opposed to animals in those areas receiving very little or no human use. Giardia spp. were also found in elk and beaver fecal samples. Campylobacter spp. were recovered infrequently from the small rodents inhabiting alpine meadows. Of 551 specimens cultured, less than 1% were positive for the bacterium, and the isolates were identified as Campylobacter coli. Water voles were susceptible to a human isolate of Campylobacter jejuni and shed the bacterium for several weeks. C. jejuni was also isolated from a bear fecal sample collected from a protected watershed. Our studies indicate that microtines and possibly other small rodents inhabiting mountain meadows have a potential to act as a reservoir for both Giardia spp. and Campylobacter spp. Because these animals may carry human pathogens, they should be included in animal surveys designed to assess the health risks associated with mountain watersheds.     

Small rodents and other mammals associated with mountain meadows as reservoirs of Giardia spp. and Campylobacter spp.

Sixty-five percent (469 of 722) of the fecal samples collected from small rodents in the central Washington Cascade mountains were positive for Giardia spp. Trapping studies showed that microtines of the genus Microtus were heavily infected with the parasite. Morphologically the cysts and trophozoites were of the Giardia duodenalis type. Small-rodent populations appear to maintain their infection throughout the year. Our data suggest that there is no difference in the percentage of positive animals in areas receiving a lot of human use as opposed to animals in those areas receiving very little or no human use. Giardia spp. were also found in elk and beaver fecal samples. Campylobacter spp. were recovered infrequently from the small rodents inhabiting alpine meadows. Of 551 specimens cultured, less than 1% were positive for the bacterium, and the isolates were identified as Campylobacter coli. Water voles were susceptible to a human isolate of Campylobacter jejuni and shed the bacterium for several weeks. C. jejuni was also isolated from a bear fecal sample collected from a protected watershed. Our studies indicate that microtines and possibly other small rodents inhabiting mountain meadows have a potential to act as a reservoir for both Giardia spp. and Campylobacter spp. Because these animals may carry human pathogens, they should be included in animal surveys designed to assess the health risks associated with mountain watersheds.     

Stable concentrated emulsions of the 1-monoglyceride of capric acid (monocaprin) with microbicidal activities against the food-borne bacteria Campylobacter jejuni, Salmonella spp., and Escherichia coli

Of 11 fatty acids and monoglycerides tested against Campylobacter jejuni, the 1-monoglyceride of capric acid (monocaprin) was the most active in killing the bacterium. Various monocaprin-in-water emulsions were prepared which were stable after storage at room temperature for many months and which retained their microbicidal activity. A procedure was developed to manufacture up to 500 ml of 200 mM preconcentrated emulsions of monocaprin in tap water. The concentrates were clear and remained stable for at least 12 months. They were active against C. jejuni upon 160- to 200-fold dilution in tap water and caused a >6- to 7-log(10) reduction in viable bacterial count in 1 min at room temperature. The addition of 0.8% Tween 40 to the concentrates as an emulsifying agent did not change the microbicidal activity. Emulsions of monocaprin killed a variety of Campylobacter isolates from humans and poultry and also killed strains of Campylobacter coli and Campylobacter lari, indicating a broad anticampylobacter activity. Emulsions of 1.25 mM monocaprin in citrate-lactate buffer at pH 4 to 5 caused a >6- to 7-log(10) reduction in viable bacterial counts of Salmonella spp. and Escherichia coli in 10 min. C. jejuni was also more susceptible to monocaprin emulsions at low pH. The addition of 5 and 10 mM monocaprin emulsions to Campylobacter-spiked chicken feed significantly reduced the bacterial contamination. These results are discussed in view of the possible utilization of monocaprin emulsions in controlling the spread of food-borne bacteria from poultry to humans.     

The heterogeneity of Campylobacter jejuni and Campylobacter coli strains isolated from healthy cattle

AIMS: To identify campylobacters isolated from clinically healthy cattle at species level by a multiplex polymerase chain reaction (m-PCR). The heterogeneity among Campylobacter jejuni and Campylobacter coli isolates was also investigated by using a restriction fragment length polymorphism (RFLP) analysis of flagellin (flaA) gene. METHODS AND RESULTS: Samples of intestinal contents, gall bladders, liver and faeces were collected from a total number of 1154 healthy cattle. The samples were inoculated onto Preston enrichment broth and agar. Of 1154 samples, 301 (26.1%) were positive for Campylobacter spp. Using an m-PCR assay for species identification, 179 (59.5%) were positive with C. jejuni specific primers while 30 (10%) were positive with C. coli specific primers. None of the liver samples examined was positive for C. jejuni or C. coli by mPCR. All the isolates identified as C. jejuni and C. coli were successfully subtyped by flaA typing. Of the 209 isolates tested, 28 different flaA types were found. Twenty-three flaA types were identified among 179 C. jejuni isolates and the remaining five from C. coli isolates. CONCLUSIONS: Although the overall results suggest that the degree of heterogeneity among the flaA genes of thermophilic Campylobacter strains isolated from healthy cattle is relatively high, they should be treated cautiously as the number of band types for C. coli was low and band type 8 in C. jejuni was represented by a high percentage (%58). SIGNIFICANCE AND IMPACT OF THE STUDY: The findings of the present study suggest that healthy cattle can play role in the contamination of environment and human food chain by Campylobacter spp.