Rapid pulsed-field gel electrophoresis protocol for subtyping of Campylobacter jejuni

We developed a rapid pulsed-field gel electrophoresis (PFGE) protocol for subtyping Campylobacter isolates based on the standardized protocols used by PulseNet laboratories for the subtyping of other food-borne bacterial pathogens. Various combinations of buffers, reagents, reaction conditions (e.g., cell suspension concentration, lysis time, lysis temperature, and restriction enzyme concentration), and electrophoretic parameters were evaluated in an effort to devise a protocol that is simple, rapid, and robust. PFGE analysis of Campylobacter isolates can be completed in 24 to 30 h using this protocol, whereas the most widely used current protocols require 3 to 4 days to complete. Comparison of PFGE patterns obtained in six laboratories showed that subtyping results obtained using this protocol are highly reproducible.

Study of the infectivity of saline-stored Campylobacter jejuni for day-old chicks

The culturability of three Campylobacter jejuni strains and their infectivity for day-old chicks were assessed following storage of the strains in saline. The potential for colonization of chicks was weakened during the storage period and terminated 3 to 4 weeks before the strains became nonculturable. The results from this study suggest that the role of starved and aged but still culturable campylobacters may be diminutive, but even more, that the role of viable but nonculturable stages in campylobacter epidemiology may be negligible. Even high levels of maternally derived anti-campylobacter outer membrane protein serum antibodies in day-old chicks did not protect the chicks from campylobacter colonization.

Development of a ceuE-based multiplex polymerase chain reaction (PCR) assay for direct detection and differentiation of Campylobacter jejuni and Campylobacter coli in Thailand

A novel ceuE-based multiplex PCR system was developed as an efficient diagnostics test to detect and differentiate C. jejuni and C. coli. There is no cross reactivity between C. jejuni and C. coli. In addition, the assay does not produce a positive signal from other enteric bacteria including Salmonella, Shigella and Escherichia coli strains. Campylobacter detection sensitivity was determined to be equivalent to previously reported PCR for other enteric bacteria. We also noticed that silicon dioxide extraction can improve Campylobacter detection sensitivity from infected stool samples. It was demonstrated that the PCR assay developed in this study had a much better Campylobacter detection rate than the traditional culturing method (77% versus 56%). However, we also identified small numbers of culture positive stools (8%, or 16 out of 202 samples) that did not yield PCR positive results for Campylobacter. These PCR negative/culture positive stools were proven to be inhibitory to PCR amplification.

Comparison of two methods for serotyping Campylobacter spp

Two serotyping schemes (Penner and Laboratory of Enteric Pathogens [LEP]) based on soluble heat-stable antigens were used to analyze 3,788 Campylobacter sp. isolates. A significant percentage (36.6%) was untypeable using LEP serotyping; greater cross-reaction was also observed. The relative discrimination capabilities of the techniques were similar. Penner serotyping fulfils more of the requisite criteria for typing methods.

Role of batch depletion of broiler houses on the occurrence of Campylobacter spp. in chicken flocks

AIMS

The effect of batch depletion of broiler houses for campylobacter occurrence in broiler flocks was estimated in 10 flocks, each comprising a separate female and male batch.

METHODS AND RESULTS

The chicks were sampled first by cloacal swabs in the broiler houses before the start of the depopulation and secondly, on arrival at the abattoir. Females were slaughtered at 5 weeks of age, males at 6 weeks. The number of campylobacter-positive batches increased from five to seven female batches, and from five to 10 male batches, between the two sampling rounds.

CONCLUSION

It is concluded that batch depletion of broiler houses increased the prevalence of Campylobacter spp.-infected broilers in the flocks, that the introduction occurred when catching the first batch, and that campylobacter spreads through the entire flock within a week.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results from this study emphasize the need to manage depopulation of broiler houses as quickly as possible and in one batch only.

Investigation of infection with Campylobacter jejuni in a man with hypogammaglobulinaemia using PCR-single-stranded conformational polymorphism (PCR-SSCP) typing

This study investigated several episodes of infection of Campylobacter jejuni in an immunocompromised male with hypogammaglobulinaemia, presenting with diarrhoea and bacteraemia over a 16-month period, by employing three phenotyping and four genotyping schemes, including the single-stranded conformational polymorphism (SSCP) technique to establish if infection was reinfection or persistent infection. Four isolates from blood culture and two faecal isolates of Campylobacter jejuni were obtained from the patient by direct selective plating on Skirrow Selective agar. Isolates were characterised at the sub-species level by Penner serology, Preston biotyping, Preston phage-typing, as well as E3CJC2 restriction fragment length polymorphism (RFLP), 16S ribotyping, flagellin (flaA) RFLP and single-stranded conformational polymorphism (SSCP) analyses. Phenotyping and genotyping sub-species analyses demonstrated that the patient was infected with at least two different strains of Campylobacter jejuni, i. e. one strain that persisted throughout the 16-month period and another strain that was transient suggesting reinfection from a different source. SSCP analysis was the most discriminatory of all the typing schemes examined and demonstrated an altered genotype of the persistent strain, whereby there were subtle modifications to the hypervariable regions of the flaA gene. Overall, as SSCP examines the hypervariable region of the flaA gene and as this technique can detect point mutations, differences between SSCP banding patterns may represent markers and thus examine mutations that occur under immune selection, thereby permitting the C. jejuni to evade the host immune response. In conclusion, this study describes the novel use of SSCP genotyping of C. jejuni and demonstrated that this method is a highly discriminatory technique which may be beneficial in outbreak characterisation, but which is not suitable to examine the clonal patterns of C. jejuni over a long period of time.

Allelic diversity and recombination in Campylobacter jejuni

The allelic diversity and population structure of Campylobacter jejuni were studied by multilocus nucleotide sequence analysis. Sequences from seven housekeeping genes were obtained from 32 C. jejuni isolates isolated from enteritis patients in Germany, Hungary, Thailand, and the United States. Also included was strain NCTC 11168, the complete genomic sequence of which has recently been published. For all loci analyzed, multiple strains carried identical alleles. The frequency of synonymous and nonsynonymous sequence polymorphisms was low. The number of unique alleles per locus ranged from 9 to 15. These alleles occurred in 31 different combinations (sequence types), so that all but two pairs of strains could be distinguished from each other. Sequences were analyzed for evidence of recombination by the homoplasy test and split decomposition. These analyses showed that intraspecific recombination is frequent in C. jejuni and has generated extensive diversity of allelic profiles from a small number of polymorphic nucleotides.

Molecular characterization of invasive and noninvasive Campylobacter jejuni and Campylobacter coli isolates

Campylobacter jejuni is one of the most common causes of bacterial diarrhea worldwide and is the primary bacterial cause of food-borne illness. Adherence to and invasion of epithelial cells are the most important pathogenic mechanisms of Campylobacter diarrhea. Molecular characterization of invasive and noninvasive Campylobacter isolates from children with diarrhea and symptom-free children was performed by random amplified polymorphic DNA techniques (RAPD). A distinct RAPD profile with a DNA band of 1.6 kb was observed significantly more frequently among invasive (63%) than among noninvasive (16%) Campylobacter isolates (P = 0.000005). The 1.6-kb band was named the invasion-associated marker (IAM). Using specifically designed primers, a fragment of 518 bp of the iam locus was amplified in 85% of invasive and 20% of noninvasive strains (P = 0.0000000). Molecular typing with a PCR-restriction fragment length polymorphism assay which amplified the entire iam locus showed a HindIII restriction fragment polymorphism pattern associated mainly with invasive strains. Although cluster analysis of the RAPD fingerprinting showed genetic diversity among strains, two main clusters were identified. Cluster I comprised significantly more pathogenic and invasive isolates, while cluster II grouped the majority of nonpathogenic, noninvasive isolates. These data indicate that most of the invasive Campylobacter strains could be differentiated from noninvasive isolates by RAPD analysis and PCR using specific primers that amplify a fragment of the iam locus.

Use of pulsed-field gel electrophoresis and flagellin gene typing in identifying clonal groups of Campylobacter jejuni and Campylobacter coli in farm and clinical environments

Although campylobacters have been isolated from a wide range of animal hosts, the association between campylobacters isolated from humans and animals in the farm environment is unclear. We used flagellin gene typing and pulsed-field gel electrophoresis (PFGE) to investigate the genetic diversity among isolates from animals (cattle, sheep, and turkey) in farm environments and sporadic cases of campylobacteriosis in the same geographical area. Forty-eight combined fla types were seen among the 315 Campylobacter isolates studied. Six were found in isolates from all four hosts and represented 50% of the total number of isolates. Seventy-one different SmaI PFGE macrorestriction profiles (mrps) were observed, with 86% of isolates assigned to one of 29 different mrps. Fifty-seven isolates from diverse hosts, times, and sources had an identical SmaI mrp and combined fla type. Conversely, a number of genotypes were unique to a particular host. We provide molecular evidence which suggests a link between campylobacters in the farm environment with those causing disease in the community.

Sporadic Campylobacter jejuni infections in Hawaii: associations with prior antibiotic use and commercially prepared chicken

Campylobacter is the most common cause of bacterial foodborne illness in the United States, and Hawaii has the highest rate of Campylobacter jejuni infections in the nation. A case-control study was conducted to determine indigenous exposures that contribute to the high incidence of sporadic C. jejuni infection in Hawaii. A total of 211 case patients with diarrhea and confirmed Campylobacter infection was enrolled, along with 1 age- and telephone exchange-matched control subject for each patient. Participants were interviewed about illness, medicines, food consumption, food-handling practices, and exposure to animals. In matched logistic regression analyses, eating chicken prepared by a commercial food establishment in the 7 days before case illness onset (adjusted odds ratio [AOR], 1.8; P=.03) and consuming antibiotics during the 28 days before illness onset (AOR, 3.3; P=.03) were significant independent predictors of illness. Further study of the association of Campylobacter illness with commercially prepared chicken and prior antibiotic use is needed.

Shared antigenicity between Helicobacter pylori and periodontopathic Campylobacter rectus strains

Periodontopathic Campylobacter rectus strains possess 41- and 68-kDa proteinaceous antigens which share antigenicity with antigens of Helicobacter pylori strains. H. pylori strains have a 54-kDa antigen which reacts with C. rectus strains. We found that the salivary IgA levels against H. pylori were correlated with those against C. rectus. These cross-reactive antigens of C. rectus may affect the serological diagnosis of H. pylori infections, especially when saliva is used. It is possible that these cross-reacting antigens may relate to the induction of immunopathological responses against both microorganisms.

Genomic relatedness within five common Finnish Campylobacter jejuni pulsed-field gel electrophoresis genotypes studied by amplified fragment length polymorphism analysis, ribotyping, and serotyping

Thirty-five Finnish Campylobacter jejuni strains with five SmaI/SacII pulsed-field gel electrophoresis (PFGE) genotypes selected among human and chicken isolates from 1997 and 1998 were used for comparison of their PFGE patterns, amplified fragment length polymorphism (AFLP) patterns, HaeIII ribotypes, and heat-stable (HS) serotypes. The discriminatory power of PFGE, AFLP, and ribotyping with HaeIII were shown to be at the same level for this selected set of strains, and these methods assigned the strains into the same groups. The PFGE and AFLP patterns within a genotype were highly similar, indicating genetic relatedness. The same HS serotypes were distributed among different genotypes, and different serotypes were identified within one genotype. HS serotype 12 was only associated with the combined genotype G1 (PFGE-AFLP-ribotype). These studies using polyphasic genotyping methods suggested that common Finnish C. jejuni genotypes form genetic lineages which colonize both humans and chickens.

An integron cassette carrying dfr1 with 90-bp repeat sequences located on the chromosome of trimethoprim-resistant isolates of Campylobacter jejuni

The frequent occurrence of high-level trimethoprim resistance in clinical isolates of Campylobacter jejuni was shown to be related to the acquisition of foreign resistance genes (dfrl or dfr9 or both) coding for resistant variants of the enzyme dihydrofolate reductase, the target of trimethoprim. The dfr1 gene detected on the chromosome of 40 different clinical strains of C. jejuni was studied further regarding structure and genetic organization. Most of the dfr1 genes were found as integron cassettes inserted in the chromosome. In 36% of the examined isolated, the dfr1 gene showed identity to that previously characterized in trimethoprim-resistant Escherichia coli. In 40% of the cases, however, a variant of the dfr1 gene containing a 90-bp direct repeat was detected, and in 5% of the isolates, the repeat-containing dfr1 variant was found to occur in the form of two cassettes in tandem in an integron context. The existence of the 90-bp repeat within the coding sequence of the dfr1gene was found to play a role in the adaptation of C. jejuni to ambient concentrations of trimethoprim.

JlpA, a novel surface-exposed lipoprotein specific to Campylobacter jejuni, mediates adherence to host epithelial cells

A 1116 bp open reading frame (ORF), designated jlpA, encoding a novel species-specific lipoprotein of Campylobacter jejuni TGH9011, was identified from recombinant plasmid pHIP-O. The jlpA gene encodes a polypeptide (JlpA) of 372 amino acid residues with a molecular mass of 42.3 kDa. JlpA contains a typical signal peptide and lipoprotein processing site at the N-terminus. The presence of a lipid moiety on the JlpA molecule was confirmed by the incorporation of [3H]-palmitic acid. Immunoblotting analysis of cell surface extracts prepared using glycine-acid buffer (pH 2.2) and proteinase K digestion of whole cells indicated that JlpA is a surface-exposed lipoprotein in C. jejuni. JlpA is loosely associated with the cell surface, as it is easily extracted from the C. jejuni outer membrane by detergents, such as sarcosyl and Triton X-100. JlpA is released to the culture medium, and its concentration increases in a time-dependent fashion. The adherence of both insertion and deletion mutants of jlpA to HEp-2 epithelial cells was reduced compared with that of parental C. jejuni TGH9011. Adherence of C. jejuni to HEp-2 cells was inhibited in a dose-dependent manner when the bacterium was preincubated with anti-GST-JlpA antibodies or when HEp-2 cells were preincubated with JlpA protein. A ligand-binding immunoblotting assay showed that JlpA binds to HEp-2 cells, which suggests that JlpA is C. jejuni adhesin.

Identification of thermophilic Campylobacter spp. by phenotypic and molecular methods

AIMS

The differences between phenotyping and genotyping (polymerase chain reaction- restriction fragment length polymorphism) of Campylobacter jejuni, Campylobacter coli, Campylobacter lari and Campylobacter upsaliensis were assessed.

METHODS AND RESULTS

A total of 51, 63 and 88 strains from dogs, pigs and humans, respectively, were examined. The strains were first typed by biochemical methods, then by PCR-RFLP using AluI and Tsp509I. None of the strains were typed as Camp. lari by the PCR-RFLP. The biggest differences were found in the identification of Camp. jejuni and Camp. coli. The main discrepancies were caused with the hippurate hydrolysis test and sensitivity to cephalothin and nalidixic acid. Strains which were identified biochemically as Camp. coli and by digestion with AluI as Camp. jejuni (eight strains) were tested for the presence of the hippuricase gene.

CONCLUSION

The PCR typing results showed the presence of the hippuricase gene as unique to Camp. jejuni.

SIGNIFICANCE AND IMPACT OF THE STUDY

A reliable identification of Campylobacter spp. should be supplemented with a molecular method.

Evidence for a genetically stable strain of Campylobacter jejuni

The genetic stability of selected epidemiologically linked strains of Campylobacter jejuni during outbreak situations was investigated by using subtyping techniques. Strains isolated from geographically related chicken flock outbreaks in 1998 and from a human outbreak in 1981 were investigated. There was little similarity in the strains obtained from the different chicken flock outbreaks; however, the strains from each of three chicken outbreaks, including strains isolated from various environments, were identical as determined by fla typing, amplified fragment length polymorphism (AFLP) analysis, and pulsed-field gel electrophoresis, which confirmed the genetic stability of these strains during the short time courses of chicken flock outbreaks. The human outbreak samples were compared with strain 81116, which originated from the same outbreak but has since undergone innumerable laboratory passages. Two main AFLP profiles were recognized from this outbreak, which confirmed the serotyping results obtained at the time of the outbreak. The major type isolated from this outbreak (serotype P6:L6) was exemplified by strain 81116. Despite the long existence of strain 81116 as a laboratory strain, the AFLP profile of this strain was identical to the profiles of all the other historical P6:L6 strains from the outbreak, indicating that the genotype has remained stable for almost 20 years. Interestingly, the AFLP profiles of the P6:L6 group of strains from the human outbreak and the strains from one of the recent chicken outbreaks were also identical. This similarity suggests that some clones of C. jejuni remain genetically stable in completely different environments over long periods of time and considerable geographical distances.

Neonatal sepsis by Campylobacter jejuni: genetically proven transmission from a household puppy

We report a case of neonatal Campylobacter jejuni sepsis in a 3-week-old infant who acquired the infection through transmission from a recently acquired household puppy. Genotyping of Campylobacter strains obtained from puppy and child resulted in highly homogeneous findings. This represents the first genetically proven C. jejuni dog-human transmission.

Detection and investigation of Campylobacter jejuni by polymerase chain reaction-restriction fragment length polymorphism analysis

A molecular typing approach for Campylobacter jejuni with restriction fragment length polymorphism (RFLP) analysis of the flagellin gene flaA in C. jejuni, was generated and studied. Using polymerase chain reaction (PCR)-RFLP with the restriction endonuclease Mbo I, it was demonstrated that C. jejuni could be divided into four types. Genotypic analysis of C. jejuni by PCR-RFLP is a valuable technique for epidemiological typing.

Comparison of mucosal competitive exclusion and competitive exclusion treatment to reduce Salmonella and Campylobacter spp. colonization in broiler chickens

Control of Salmonella spp. during the earliest phases of broiler production may provide the best opportunity to reduce human pathogens on processed broiler carcasses. Application of the "Nurmi concept" has been demonstrated to be an effective means in reducing Salmonella colonization among broiler chicks. In 1989, Aho et al. developed a competitive exclusion (CE) culture for control of Salmonella spp., whereas a mucosal competitive exclusion culture (MCE) developed in the United States was originally created to control Campylobacter colonization (Stern et al., 1995). The major differences in the two patents were the higher level of anaerobic culture required, the degree of epithelial scraping and washing of the ceca, media used for subculturing, and the culture incubation temperatures (35 C vs. 42 C). The CE and MCE were compared for efficacy in reducing Salmonella and Campylobacter colonization in broiler chicks. Nine adult birds (three for each of three replicates) were slaughtered, and each of a bird's paired ceca were used to produce corresponding antagonistic microflora, which were administered to day-of-hatch chicks. The chicks (a total of 210) were challenged 24 h later with Salmonella and Campylobacter and were killed 1 wk later, and levels of the pathogens were determined. Ninety CE-treated birds were significantly more colonized by Salmonella typhimurium than those 90 chicks treated with the MCE microflora (3.97 log 10 cfu/g cecal contents vs. 1.25 log 10 cfu/g cecal contents). Also, Campylobacter spp. colonization of these birds was significantly higher for CE-treated birds when compared with MCE-treated birds (6.96 log 10 cfu/g cecal contents vs. 5.03 log 10 cfu/g cecal contents). These results can be useful in developing intervention strategies to reduce chicken colonization by Salmonella and Campylobacter.

Competitive exclusion of heterologous Campylobacter spp. in chicks

Chicken and human isolates of Campylobacter jejuni were used to provide oral challenge of day-old broiler chicks. The isolation ratio of the competing challenge strains was monitored and varied, depending upon the isolates used. A PCR-restriction fragment length polymorphism assay of the flagellin gene (flaA) was used to discriminate between the chick-colonizing isolates. Our observations indicated that the selected C. jejuni colonizers dominated the niche provided by the chicken ceca. Chicken isolates from the flaA type 7 grouping generally had numerical superiority over the human isolates when they were administered in our 1-day-old chick model. Our results suggest that it is possible to use combinations of C. jejuni chicken isolates as a defined bacterial preparation for the competitive exclusion of human-pathogenic C. jejuni in poultry.

Epidemiologic features of Campylobacter jejuni isolated from poultry broiler houses and surrounding environments as determined by use of molecular strain typing

OBJECTIVE

To genetically type Campylobacter jejuni isolates from broiler houses or the external environment to identify the source of Campylobacter organisms in broiler chickens.

SAMPLE POPULATION

Environmental samples associated with broiler chickens, in commercial grow-out houses.

PROCEDURE

Polymerase chain reaction (PCR) was used to amplify flaB, and the amplicon was digested with Sau3A to create a restriction fragment length polymorphism assay; PCR was also used to detect a transcribed spacer region in the 23S rRNA gene.

RESULTS

Isolates possessing a 23S spacer region were more prevalent outside broiler houses than inside. Houses that had previously contained chickens or lacked biosecurity procedures were more likely to contain isolates possessing the 23S spacer. One house contained only isolates possessing the spacer, whereas an adjacent house contained only isolates lacking the spacer. The flaB type detected in broiler houses was different from the type detected in the environment; however, many isolates within the broiler houses contained untypable flaB genotypes.

CONCLUSIONS AND CLINICAL RELEVANCE

Most isolates from within houses were genetically distinct from isolates from outside houses that were examined by bacteriologic culture, suggesting an undetected source of C jejuni. Detection of isolates containing the 23S spacer appeared to be an indicator of environmental contamination of the houses. The observation of completely different C jejuni genetic types simultaneously within adjacent houses suggests that some types do not compete successfully during the grow-out period. In addition, the diversity of genotypes identified within broiler houses indicates the complexity of the ecologic features of C jejuni in the chicken environment.

The effects of UVB and temperature on the survival of natural populations and pure cultures of Campylobacter jejuni, Camp. coli, Camp. lari and urease-positive thermophilic campylobacters (UPTC) in surface waters

AIMS

To determine whether diurnal and seasonal variations in campylobacters in surface waters result from the effects of temperature and u.v. radiation, and whether natural populations of Campylobacter lari and urease-positive thermophilic campylobacters (UPTC) from birds survive better in surface waters than Camp. jejuni from sewage.

METHODS AND RESULTS

Natural populations of Camp. lari and UPTC in sea water, and Camp. jejuni in river water, were exposed to artificial sunlight (equivalent to a sunny day in June). Both populations became non-culturable within 30 min, with T90s of 15 min and 25 min, respectively. Cultures of Camp. jejuni became non-culturable within 40 min and those of Camp. coli, Camp. lari and UPTC, within 60 min. In darkness, survival was temperature-dependent. Natural populations took 12 h at 37 degrees C and 5 days at 4 degrees C to become non-culturable in sea water, and slightly less in river water. Cultures of Camp. lari and UPTCs survived for significantly longer than Camp. jejuni and Camp. coli. Loss of culturability for all isolates was most rapid at 37 degrees C and slowest at 4 degrees C. Newly isolated strains from sea water and river water behaved in an almost identical manner to NCTC strains.

CONCLUSION

Campylobacter lari and UPTCs survive for longer in surface waters than Camp. jejuni and Camp. coli, particularly in the dark. Low Campylobacter numbers in coastal waters in the summer, especially in the afternoon, are due to the combined effects of higher temperatures and higher levels of u.v. radiation.

SIGNIFICANCE AND IMPACT OF THE STUDY

Campylobacter lari and UPTCs from birds predominate in bathing waters in Morecambe Bay because they are better able to survive; they also originate from closer to the shore than Camp. jejuni and Camp. coli in sewage effluent, which survive poorly and die before the incoming tide reaches the shore. The predominance of Camp. jejuni in river water results from its dominance of the inputs and not from its ability to survive.

Evaluation of numerical analysis of PFGE-DNA profiles for differentiating Campylobacter fetus subspecies by comparison with phenotypic, PCR and 16S rDNA sequencing methods

AIMS

To assess the efficacy of numerical analysis of PFGE-DNA profiles for identification and differentiation of Campylobacter fetus subspecies.

METHODS AND RESULTS

31 Camp. fetus strains were examined by phenotypic, PCR- and PFGE-based methods, and the 16S rDNA sequences of 18 strains compared. Numerical analysis of PFGE-DNA profiles divided strains into two clusters at the 86% similarity level. One cluster contained 19 strains clearly identified as Camp. fetus subsp. venerealis. The other cluster comprised 12 strains, of which 10 were unambiguously identified as Camp. fetus subsp. fetus. The remaining two strains were identified as Camp. fetus subsp. venerealis by either phenotypic or PCR methods, but not both. At higher similarity levels, clusters containing isolates from each of two countries were identified, suggesting that certain clones predominate in certain geographical regions.

CONCLUSION

Numerical analysis of PFGE-DNA profiles is an effective method for differentiating Camp. fetus subspecies.

SIGNIFICANCE AND IMPACT OF THE STUDY

Critical comparison of PFGE, PCR, 16S rDNA sequencing and phenotypic methods for differentiation of Camp. fetus subspecies was attained. Novel phenotypic markers for distinguishing subspecies were identified. Evidence for dominant clones of each subspecies in certain countries was provided.

Thermophilic multidrug-resistant Campylobacter fetus infection with hypersplenism and histiocytic phagocytosis in a patient with acquired immunodeficiency syndrome

We present a case report of a patient who had acquired immunodeficiency syndrome (AIDS) and Campylobacter fetus infection with a number of unusual clinical and microbiological features. The patient had prominent gastrointestinal symptoms, splenic infarction, splenomegaly with hypersplenism, and hemophagocytic histiocytosis in the spleen and lymph nodes; the organism displayed growth on Campy-selective blood agar, thermotolerance, and resistance to quinolones, piperacillin/tazobactam, ceftazidime, and erythromycin.