cadF Genes Research Articles

Prevalence of Seven Virulence Genes of Campylobacter jejuni Isolated from Patients with Diarrhea in Rosario, Argentina

Background: Campylobacter jejuni (C. jejuni) is a major cause of human diarrheal disease. Objectives: This study was conducted to determine the prevalence of dierent pathogenic genes in isolates recovered from human stool samples in Rosario, Argentina. Methods: A total of 30 isolates were identified as C. jejuni on the basis of morphological and biochemical-based detection. The isolates were screened for the presence of seven pathogenic genes namely flaA, cadF, ciaB, cdtB, cgtB, docC and wlaN, which are re- sponsible for expression of adherence, invasion, colonization, chemotaxis and cytotoxin production in C. jejuni. Results: The isolates showed a wide variation in the presence of these genes. All the isolates were positive for flaA, cadF and cdtB genes. Of the C. jejuni studied, 40.0%, 23.3%, 20.0% and 6.7% were positive for ciaB, docC, wlaN and cgtC, respectively. Conclusions: This study provides initial data on the prevalence and distribution of the flaA, cadF, ciaB, cdtB, cgtB, docC and wlaN genes in C. jejuni.

Multiplex PCR Assay for Identifi cation and Differentiation of Campylobacter jejuni and Campylobacter coli Isolates.

Campylobacter spp. are important causative agents of gastrointestinal infections in humans. The most frequently isolated strains of this bacterial genus are Campylobacter jejuni and Campylobacter coli. To date, genetic methods for bacterial identification have not been used in Bulgaria. We optimized the multiplex PSR assay to identify Campylobacter spp. and differentiate C. jejuni from C. coli in clinical isolates. We also compared this method with the routinely used biochemical methods. To identify Campylobacter spp. and discriminate C. coli from C. jejuni in clinical isolates using multiplex PCR assay. Between February 2014 and January 2015 we studied 93 stool samples taken from patients with diarrheal syndrome and identified 40 species of Campylobacter spp. in them. The clinical material was cultured in microaerophilic atmosphere, the isolated strains being biochemically diff erentiated (hydrolysis of sodium hippurate for C. jejuni, and hydrolysis of indoxyl acetate for C. coli). DNA was isolated from the strains using QiaAmp MiniKit (QIAGEN, Germany). Twenty strains were tested with multiplex PCR for the presence of these genes: cadF, characteristic for Campylobacter spp., hipO for C. jejuni and asp for C. coli. The biochemical tests identified 16 strains of C. jejuni, 3 strains of C. coli, and 1 strain of C. upsaliensis. After the multiplex PCR assay the capillary gel electrophoresis confirmed 16 strains of C. jejuni, 2 strains of C. coli and 2 strains of Campylobacter spp. - because of the presence of the gene cadF. C. jejuni has the gene hipO, and it is possible that this gene may not be expressed in the biochemical differentiation yielding a negative reaction as a result. In comparison, we can conclude that the genetic differentiation is a more accurate method than the biochemical tests. The multiplex PCR assay is a fast, accurate method for identifi cation of Campylobacter spp. which makes it quite necessary in the clinical diagnostic practice.

Isolation and characterization of Arcobacter spp. from fresh seafood and the aquatic environment

Arcobacter is an emerging pathogen associated with foods of animal origin. Members of the genus Arcobacter are increasingly being isolated from fish, shellfish and the aquatic environment. In the present study, we analyzed fish, shellfish and water samples for the presence of Arcobacter spp. by conventional isolation as well as by direct PCR on the enrichment broth. Of 100 samples comprising of 42 finfish, 34 shellfish and 24 water samples analyzed, Arcobacter spp. was isolated from 8 (19%) finfish, 5 (14.7%) shellfish and 5 (20.8%) water samples. Arcobacter DNA was detected in 24 (24%) samples by direct PCR on the enrichment broth. Based on m-PCR specific to different Arcobacter spp. and 16S rRNA sequence analyses, majority (19) of the isolates were identified as Arcobacter butzleri, while two isolates were Arcobacter mytili. All Arcobacter butzleri isolates harbored putative virulence genes cadF, ciaB, mviN, pldA, tlyA and cj1349. The two isolates of A. mytili harbored mviN and cj1349 genes only. The study highlights emerging problem of the contamination of aquatic environment and fresh seafood with potentially pathogenic Arcobacter spp.

In Silico Analysis of the cadF Gene and Development of a Duplex Polymerase Chain Reaction for Species-Specific Identification of Campylobacter jejuni and Campylobacter coli.

BackgroundCampylobacteriosis is a zoonotic infectious disease caused by Campylobacter jejuni and C. coli. The cadF gene is considered as a genus-specific gene while other genes are mainly used for discrimination at the species level.ObjectivesThis study aimed to analyze the cadF gene and to develop a duplex PCR assay for simultaneous detection of C. coli and C. jejuni, the two commonly encountered species.Materials and MethodsIn silico analysis of the cadF gene was carried out by several software and available online tools. A duplex PCR optimized with specific primers was used for detection and differentiation of both species. To evaluate specificity and sensitivity of the test, a panel of different Campylobacter spp. together with several intestinal bacterial pathogens was tested. The limit of detection (LOD) of method was determined using serial dilutions of standard genomes.ResultsThe analysis of the full size cadF gene indicated variations in this gene, which can be used to differentiate C. jejuni and C. coli. The duplex PCR designed in this study showed that it could simultaneously detect and differentiate both C. jejuni and C. coli with product sizes of 737 bp and 461 bp, respectively. This assay, with 100% specificity and sensitivity, had a limit of detection (LOD) of about 14 and 0.7 µg/mL for C. jejuni and C. coli, respectively.ConclusionsIn silico analysis of the cadF full-gene showed variations between the two species that can be used as a molecular target for differentiating C. jejuni and C. coli in a single-step duplex-PCR assay with high specificity and sensitivity.

Monitoring of Virulence Genes, Drug-Resistance in Campylobacter coli Isolated from Golden Retrievers.

The investigation was performed on 75 of Golden Retriever puppies. Faecal samples were collected on the 42 day of the puppies life (con-trol). Probiotic preparation was administered on 43 day of the puppies life and 10 days after the application of the probiotic, faecal samples were collected again (on 53 day of puppies life). All isolates of Campylobacter coli isolated prior to the administration of the probiotic were found to contain the cadF gene responsible for adhesion, as well as, the flaA gene influencing motility of the examined bacteria. Significant differences (P < 0.05) were recorded only in the case of enrofloxacin.

Typing of Campylobacter jejuni Isolated from Turkey by Genotypic Methods, Antimicrobial Susceptibility, and Virulence Gene Patterns: A Retrospective Study.

In this retrospective study, typing ability, discriminatory power, and concordance between typing results obtained on 123 Campylobacter jejuni turkey isolates, collected in 1998, within 14 different farms, applying multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), antibiotic resistance profile, and virulence gene pattern, were assessed and compared. Overall, 33 sequence types, 28 pulsotypes, 10 resistotypes, and 5 pathotypes were identified. MLST and PFGE showed the better discriminatory ability (i.e., Simpson's diversity index >0.90) as well as unidirectional (i.e., Wallace and adjusted Wallace coefficients >0.86) and bidirectional (i.e., adjusted Rand coefficient >0.60) concordance. Moreover, both methods showed a good unidirectional and bidirectional concordance with the resistotype. On the contrary, the congruence of both genotyping methods and resistotype with the pathotype seemed due to chance alone. A clonal relationship was identified among 66.7% of the isolates. Furthermore, 59.7% of the investigated isolates were resistant to two or more antimicrobials and 92% to tetracycline. All the isolates harbored cadF and pldA genes, whereas a flaA gene product and a cdtB gene product were amplified from 85.4% and 79.7% of the isolates, respectively, using the primers designed by Bang et al. (2003). The results of this study clarify the level of genetic diversity among the C. jejuni originating from turkeys. MLST level of correlation with PFGE, resistotype, and pathotype is assessed. This result supports the selection of type and number of typing methods to use in epidemiological studies. Finally, the identification of clonal complexes (i.e., groups of profiles differing by no more than one gene from at least one other profile of the group using the entire Campylobacter MLST database) shared between turkey and human isolates suggests that turkeys could be a possible source of Campylobacter infection.

Comparison of Antimicrobial Susceptibility of Campylobacter Strains Isolated from Food Samples and Patients with Diarrhea

Background: Campylobacter infections may lead to serious conditions, including septicemia or other invasive forms of the disease, which require rapid and accurate laboratory diagnosis and subsequently appropriate antimicrobial therapy. The aim of this study was to compare the species distribution and antimicrobial susceptibility pattern of Campylobacter spp. strains isolated from patients and food samples. Methods:Biochemical identification was performed on 15 clinical and 30 food isolates of Campylobacter recovered onto Brucella agar containing 5% sheep blood. PCR was carried out to confirm the identity of Campylobacter spp. using primers for cadF, hipO, and asp genes of Campylobacter. To determine antibiotic sensitivity of isolates, Kirby-Bauer assay was carried out using 16 different antibiotic discs. Results:PCR assay and biochemical tests confirmed all 45 isolates as Campylobacter: 20 (44.44%) as C. jujeni, 10 (22.22%) as C. coli, and 15 (33.34%) as other Campylobacter strains. The maximum resistance was observed to cefotaxime and imipenem (each 86.49%) and the maximum sensitivity to erythromycin (48.65%). Conclusion: C. jujeni is dominant among isolates from clinical and food samples. In addition, tetracycline remains the first-line therapeutic agent against Campylobacter infections in Iran.

Phenotypic Characters and Molecular Epidemiology of Campylobacter Jejuni in East China.

In this study, we investigated the distribution, phenotypic and molecular typing characters of Campylobacter jejuni in domestic fowl, and livestock populations in East China, to provide some reference for researches on its molecular epidemiology. A total of 1250 samples were collected from different animal sources, and C. jejuni strains were then isolated and tested for antibiotic sensitivity. Antibiotics-resistance gene and pathogenic genes were detected by polymerase chain reaction. Phylogenic analysis on the C. jejuni strains was performed by multilocus sequence typing (MLST) method. The results showed that 108 out of the 1250 samples (mean 8.64%) were C. jejuni positive. These 108 C. jejuni strains were highly sensitive to antibiotics such as chloramphenicol, amoxicillin, amikacin, cefotaxime, and azithromycin, whereas they were highly resistant to antibiotics such as cefoperazone, cotrimoxazole, cefamandole, sulfamethoxazole, and cefradine. Pathogenicity related gene identification indicated that the mean carrying rate of adhesion related gene cadF and racR, flagellin gene flaA, toxin regulating gene cdtA, cdtB, cdtC, wlaN and virB11, heat shock proteins and transferring proteins related genes dnaJ and ceuE, CiaB and pldA were 92.45%, 38.69%, 73.58%, 71.70%, 52.83%, 96.23%, 12.26%, 1.89%, 0.94%, 65.09%, 39.62% and 9.43%, respectively. A total of 58.82% of these strains contained more than 6 pathogenicity-related genes. MLST typed 58 ST types from the 108 isolated C. jejuni strains, including 24 new types, and ST-21 was the major type, accounting for 39.3% of the total strains.

Prevalence of ten putative virulence genes in the emerging foodborne pathogen Arcobacter isolated from food products

Arcobacter spp. are considered to be emerging food- and waterborne pathogens for both humans and animals. However, their virulence mechanisms are still poorly understood. In this study the presence of ten virulence genes (cadF, ciaB, cj1349, hecA, hecB, mviN, pldA, irgA, tlyA and iroE) was assessed in a set of 47 strains of Arcobacter butzleri, 10 of Arcobacter cryaerophilus and 1 Arcobacter skirrowii strain recovered from different food products (pork, chicken, beef, milk, clams and mussels). Overall, the genes cadF, ciaB, cj1349, mviN, pldA and tlyA were detected in all A. butzleri and A. skirrowii strains. Lower detection rates were observed for irgA, iroE, hecA and hecB. The genes hecB and iroE were detected neither in A. cryaerophilus nor in A. skirrowii. The genes hecA and irgA were not detected in A. skirrowii. It was noteworthy that the genes hecA and hecB were significantly (P < 0.05) highly detected in A. butzleri strains isolated from clams compared with strains isolated from milk and chicken. Therefore, our findings underline clams as a source of A. butzleri strains with high prevalence of putative virulence genes. This could be hazardous to human health, especially because these bivalves are usually consumed raw or undercooked.

Virulence genes and cytokine profile in systemic murine Campylobacter coli infection

Campylobacter coli are one of the most common bacteria in bacterial gastroenteritis and acute enterocolitis in humans. However, relatively little is known regarding the mechanisms of pathogenesis and host response to C. coli infections. To investigate the influence of genetic changes, we first used PCR to demonstrate the presence of the known virulence genes cadF, virB11, cdtB, cdtC and ceuE in the clinical isolate C. coli 26536, which was isolated from the liver of infected BALB/c mice. Sequence analyses of the cadF, virB11, cdtB and ceuE genes in C. coli 26536 confirmed the stability in these virulence genes during their transmission through the host. We further investigated C. coli infection for the bacterial clearance from the liver and spleen of infected mice, and for their immune response. C. coli persisted well in both organs, with better survival in the liver. We also determined the levels of several pro-inflammatory cytokines (i.e., interleukin [IL]-6, IL-12, interferon-γ, tumor necrosis factor-α) and the anti-inflammatory cytokine IL-10 in plasma and in liver homogenates from the infected mice, using enzyme-linked immunosorbent assays. The lowest levels among these cytokines were for tumor necrosis factor-α in the plasma and IL-6 in the liver on days 1, 3 and 8 post-infection. The most pronounced production was for IL-10, in both plasma (days 1 and 8 post-infection) and liver (day 8 post-infection), which suggests that it has a role in healing of the organ inflammation. Our findings showed dynamic relationships between pro- and anti-inflammatory cytokines and thus contribute toward clarification of the healing processes involved in the resolution of C. coli infections.

The prevalence of Campylobacter spp. and occurrence of virulence genes isolated from dogs

This study was conducted to determine the prevalence of Campylobacter spp. isolated from dogs' faecal samples. From June 2012 to June 2013, a total of 210 faecal samples from pet dogs living in different kennels (n = 210) were collected by the owners in Greater Poland Voivodeship, Poznań District, Poland. The study revealed that 105 out of 210 faecal samples (50%) contained Campylobacter. The highest prevalence of Campylobacter spp. occurred in spring (81%), followed by winter (64%). The cadF gene was found in 100% of the isolates tested. The occurrence of the other genes was variable. The isolates from young dogs were characterised by higher occurrence of virulence genes.

Prevalence of Campylobacter species in milk and milk products, their virulence gene profile and anti-bio gram.

Aim:During the last decades, number of food poisoning cases due to Campylobacter occurred, immensely. After poultry, raw milk acts as a second main source of Campylobacter. Therefore, the present study was undertaken to detect the prevalence of Campylobacters in milk and milk products and to know the antibiotic sensitivity and virulence gene profile of Campylobacter spp. in Anand city, Gujarat, India.Material and Methods:A total of 240 samples (85 buffalo milk, 65 cow milk, 30 cheese, 30 ice-cream and 30 paneer) were collected from the different collection points in Anand city. The samples were processed by microbiological culture method, and presumptive isolates were further confirmed by genus and species-specific polymerase chain reaction using previously reported primer. The isolates were further subjected to antibiotic susceptibility assay and virulence gene detection.Result:Campylobacter species were detected in 7 (2.91%) raw milk samples whereas none of the milk product was positive. All the isolate identified were Campylobacter jejuni. Most of the isolates showed resistance against nalidixic acid, ciprofloxacin, and tetracyclin. All the isolates have three virulence genes cadF, cdtB and flgR whereas only one isolate was positive for iamA gene and 6 isolates were positive for fla gene.Conclusion:The presence of Campylobacter in raw milk indicates that raw milk consumption is hazardous for human being and proper pasteurization of milk and adaptation of hygienic condition will be necessary to protect the consumer from this zoonotic pathogen.

Prevalence, virulence, and antimicrobial resistance of Campylobacter jejuni and Campylobacter coli in white stork Ciconia ciconia in Poland.

The aim of this study was to investigate the role of white stork Ciconia ciconia as a potential reservoir of Campylobacter spp. Antimicrobial resistance and the presence of putative virulence genes of the isolates were also examined. A total of 398 white stork chicks sampled in Western Poland in habitats with high density of breeding were examined. Rectal swabs were collected during breeding season 2009-2012 from storks developing in a relatively pure environment (Odra meadows), in polluted areas (a copper mining-smelting complex), and in suburbs. Of the anal swabs collected, 7.6% were positive for Campylobacter among chicks (5.3% samples positive for C. jejuni and 2.3% samples positive for C. coli). Samples from polluted areas had the highest prevalence of Campylobacter (12.2%). The prevalence of resistance among C. jejuni and C. coli isolates from young storks was as follows: to ciprofloxacin (52.4%, 44.4%), and to tetracycline (19%, 77.8%). All of the analyzed isolates were susceptible to macrolides. The resistance to both classes of antibiotics was found in the 23.3% of Campylobacter spp. All Campylobacter spp. isolates had cadF gene and flaA gene responsible for adherence and motility. CdtB gene associated with toxin production was present in 88.9% of C. coli isolates and 57.1% of C. jejuni isolates. The iam marker was found more often in C. coli strains (55.6%) compared to C. jejuni isolates (42.9%). Our results confirm the prevalence of Campylobacter spp. in the white stork in natural conditions and, because it lives in open farmlands with access to marshy wetlands, the environmental sources such as water reservoirs and soil-water can be contaminated from white stork feces and the pathogens can be widely disseminated. We can thus conclude that Campylobacter spp. may easily be transmitted to waterfowl, other birds, and humans via its environmental sources and/or by immediate contact.

Trends in the occurrence and characteristics of Campylobacter jejuni and Campylobacter coli isolates from poultry meat in Northern Poland

The aim of this study was to investigate the occurrence of Campylobacter spp. in poultry meat available in retail stores in the northern part of Poland during a five-year period (2009–2013). A total of 742 poultry meat samples were collected from butcher shops and supermarkets including the following types of samples: chicken breast filets (n = 133), turkey breast filets (n = 112), chicken wings (n = 135), chicken leg quarters (n = 128), chicken drumsticks (n = 115), and chicken giblets (n = 119).The results indicated that 41.6% of the samples were positive for Campylobacter spp., and Campylobacter jejuni was predominant in this study. The prevalence of Campylobacter spp. changed during the study period, decreasing from 60.2% in 2009 to 32% in 2013.The characterization of the isolates revealed a high prevalence of Campylobacter virulence genes. All Campylobacter spp. isolates from poultry meat contained the cadF gene, which is responsible for adherence. The flaA gene, which is involved in motility, was present in all C. jejuni and Campylobacter coli strains. The cdtB, which is associated with toxin production, was present in 93.3% of C. jejuni strains and 89.6% of C. coli strains. The iam gene, which is associated with the invasiveness of Campylobacter spp., was predominant in C. coli strains (95.6%) compared to C. jejuni strains (84.5%).Resistance to four antimicrobials was also examined. The prevalence of resistance among the obtained C. jejuni and C. coli isolates was as follows: ciprofloxacin (62.8% and 72.2%, respectively), tetracycline (42.3% and 42.6%, respectively), erythromycin (3% and 1.7%, respectively) and azithromycin (1%). Multidrug resistance was more frequent among C. jejuni isolates (29.8%) than among C. coli isolates (18.2%).In conclusion, the results of this study demonstrated the importance of poultry meat as a source of Campylobacter spp., especially macrolide-resistant strains. The trend of decreasing Campylobacter spp. occurrence in retail poultry meat in this region of Poland requires further investigation, and monitoring.

A molecular survey of Campylobacter jejuni and Campylobacter coli virulence and diversity.

Background: The aim of this study was to determine the prevalence of virulence-associated genes and enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) analysis of Campylobacter spp. isolated from children with diarrhea in Iran. Methods: A total of 200 stool specimens were obtained from children under 5 years during July 2012 to July 2013. Detection of C. jejuni and C. coli was performed by standard biochemical and molecular methods. The presence of virulence-associated genes and genetic diversity of isolates was examined using PCR and ERIC-PCR analyses. Results: A total of 12 (6%) Campylobacter spp. were isolated from patients including 10 (4.5%) C. jejuni and 2 (1.5%) C.coli. The flaA, cadF and ciaB genes were present in 100% of isolates, while no plasmid of virB11 gene was present in their genome. The prevalence of invasion-associated marker was 100% among C. coli and was not detected in C. jejuni isolates. The distribution of both pldA and the genes associated with cytolethal distending toxin (CDT) was 58.3% in C. jejuni isolates. Seven distinct ERIC-PCR profiles were distinguished in three clusters using ERIC-PCR analysis. Genotyping analysis showed a relative correlation with geographic location of patients and virulence gene content of isolates. Conclusion: To our knowledge, this is the first molecular survey of Campylobacter spp. in Iran concerning genotyping and virulence gene content of both C. jejuni and C. coli. ERIC-PCR revealed appropriate discriminatory power for clustering C. jejuni isolates with identical virulence gene content. However, more studies are needed to clearly understand the pathogenesis properties of specific genotypes.

Occurrence of virulence genes and strain diversity of thermophilic campylobacters isolated from cattle and sheep faecal samples

The objective of this study was to investigate the genotypic characteristics of Campylobacter isolates in Shiraz, Iran. A total of 40 Campylobacter isolates including 20 C. jejuni and 20 C. coli were recovered from both cattle and sheep faeces by cultivation methods. The isolates were identified on the basis of polymerase chain reaction (PCR) detection of 16SrRNA and multiplex PCR to determine two species. For confirmed isolates, PCR was carried out for the presence of virulence genes using specific primers. Other than verifying the genetic diversity of thermophilic Campylobacter isolates, flaA PCR-RFLP was performed. Results showed the high prevalence (100%) of the cadF gene and three genes associated with cytolethal distending toxin (CDT). Plasmid virB11 gene was not found in any Campylobacter isolate, and dissimilarities and discrepancies occurred in pldA, iamA, wlaN, waaC and cgtB genes. Among the 40 Campylobacter isolates studied, nine different types were defined by flaA-typing. Results indicated genetic diversity among Campylobacter isolates recovered from cattle and sheep faecal samples. Findings showed the potential ability of C. jejuni and C. coli with cattle and sheep origins to cause infection in humans.

Prevalence of virulence-associated genes and antimicrobial resistance of Campylobacter jejuni from ducks in Gyeongnam Province, Korea

Total 99 strains of Campylobacter spp. were isolated from 117 cases of duck's fecal samples. Among 99 strains of Campylobacter spp. isolates, 93 strains (93.9%) were C. jejuni and 6 strains (6.1%) were C. coli. Prevalence of virulence and GBS associated genes of 72 C. jejuni isolates was determined by m-PCR. Among the 10 kinds of virulence associated genes, cadF, dnaJ, flaA and ceuE genes were detected in all of C. jejuni isolates from ducks, racR, pldA, iamA, ciaB, virB11 and docC genes were 87.5%, 84.7%, 77.8%, 48.6%, 13.9% and 11.1%, respectively. Antimicrobial susceptibility test was performed on 72 C. jejuni isolates. The rate of resistance were 62.5% for oxytetracycline, 55.6% for kanamycin, 54.2% for enrofloxacin, 50% for ciprofloxacin, 37.5% for tetracycline and nalidixic acid, 18.1% for ampicillin, 15.3% for streptomycin, and 6.9% for ofloxacin. All isolates were susceptible to erythromycin. The adherence (intracellular and extracellular bacteria) abilities of the 20 isolates to INT-407 cells were between <TEX>$4.21{\pm}1.27{\times}10^4$</TEX> CFU/well and <TEX>$1.053{\pm}0.451{\times}10^6$</TEX> CFU/well from the isolates of cj-55 and cj-52, respectively, and that can be expressed as 0.1033% to 5.2655% to the infecting inoculum. The invasion (intracellular bacteria) abilities of the 20 isolates to INT-407 were between <TEX>$1.00{\pm}1.73{\times}10^3$</TEX> CFU/well and <TEX>$8.47{\pm}5.16{\times}10^4$</TEX> CFU/well from the isolates of cj-13 and cj-47, respectively, and that can be expressed as 0.0050% to 0.4235% to the infecting inoculums. The average CFU/well of 20 campylobacters isolated from ducks for adherence to and invasion were <TEX>$2.646{\pm}2.886{\times}10^5$</TEX> and <TEX>$3.03{\pm}2.7{\times}10^4$</TEX> respectively, and that was <TEX>$1.3230{\pm}1.2139%$</TEX> and <TEX>$0.1516{\pm}0.1343%$</TEX> of the starting viable inoculum. There was considerable correlation (<TEX>$R^2$</TEX>=0.627) between the adherence and invasion ability of C. jejuni isolates for INT-407 cell.

Characterization of the virulence, growth temperature and antibiotic resistance of the Campylobacter jejuni IAL 2383 strain isolated from humans.

The objective of this study was to characterize the C. jejuni IAL2383 strain isolated from humans in Brazil. Transcripts for the racR, dnaJ and ciaB genes were found and flaA, plda and cadF genes were present in the genome and bacteria was sensitive to most of the important antimicrobials used to treat humans. C. jejuni IAL2383 is a good experimental model to analyze the interactions with cells.

Occurrence of six virulence-associated genes in Arcobacter species isolated from various sources in Shiraz, Southern Iran

In humans, arcobacters are associated with watery diarrhea and septicemia. Although, recently, more cases of diarrhea have been caused by Arcobacter species, very little is known about its pathogenesis. Therefore, the aim of this study was to evaluate the presence of six putative Arcobacter virulence genes (cadF, ciaB, cj1349, mviN, pldA, and tlyA), in a set of 113 Arcobacter butzleri, 40 Arcobacter cryaerophilus, and 15 Arcobacter skirrowii isolates that were recovered from various origins. The isolates were confirmed on the basis of polymerase chain reaction (PCR) amplification of genus and species specific PCR for determining three species. For confirmed isolates, PCR was carried out for the presence of virulence genes using specific primers. All A. butzleri isolates carried all six genes. For A. cryaerophilus and A. skirrowii, the cadF gene was detected just in 55 and 53.3%, ciaB in 97.5 and 86.6%, cj1349 in 45 and 60%, mviN in 90 and 80%, pldA in 32.5 and 13.3%, and tlyA in 37.5 and 40%, respectively. For A. cryaerophilus and A. skirrowii, the genes ciaB and mviN were significantly more prevalent than other virulence markers (P ≤ 0.05). The findings revealed that many of the important Arcobacter strains (86%) have these putative virulence genes which can be potential pathogenic properties for humans.

Characteristics and antimicrobial resistance of Campylobacter isolated from pig and cattle carcasses in Poland

A total of 70 Campylobacter isolates recovered from 114 cattle and 177 pig carcasses at the slaughterhouse level were characterized by the presence of 7 putative virulence genes and antimicrobial susceptibility using the microbroth dilution method and minimal inhibitory concentration (MIC). The prevalence of Campylobacter was 14.9% and 29.9% in cattle and pig samples, respectively. The majority of cattle carcasses were contaminated with C. jejuni (64.7%), whereas pig carcasses were mainly positive for C. coli (77.4%). Most of the strain, irrespective of origin, possessed at least one pathogenic gene marker tested, mainly flaA and cadF genes responsible for motility and adherence to host epithelial cells, respectively. Several isolates also possessed the cdtA and cdtB genes responsible for the production of cytolethal distending toxin. Antibiotic profiling showed that campylobacters were most frequently resistant to quinolones (nalidixic acid and ciprofloxacin, total 57.1% of isolates) followed by streptomycin (52.9%, only C. coli strains) and tetracycline (51.4%). Resistance to erythromycin was demonstrated only in 4 C. coli strains of pig origin. None of the isolates, irrespective of origin, was resistant to gentamycin. Multi-resistance patterns, defined as resistance to antimicrobials of at least two different classes, were observed among 65.4% of the isolates, mainly C. coli recovered from pig carcasses.