Bacteremia due to Campylobacter species: clinical findings and antimicrobial susceptibility patterns

Campylobacter Infections With and Without Bacteremia: A Comparative Retrospective Population-Based Study

Background

Bacteremia with species in the genus Campylobacter is rare, and knowledge of the disease course in comparison with Campylobacter enteritis is limited.

Methods

This is a retrospective population-based study. Episodes of Campylobacter bacteremia and Campylobacter enteritis with a concurrent negative blood culture result that occurred between 2015 and 2022 in southern Sweden were identified through the laboratory database. Medical records were reviewed, and clinical features between patients with bacteremic Campylobacter infections were compared with patients with Campylobacter spp found in feces.

Results

The study included 29 bacteremic infections with Campylobacter and 119 cases of Campylobacter spp found in feces. Patients with Campylobacter bacteremia were significantly older than those with enteritis (72 years [IQR, 58-62] vs 58 years [IQR, 33-67], P < .0001). Eleven patients with bacteremia developed sepsis within 48 hours from blood culturing, and no patient died within 30 days from hospital admission.

Conclusions

Campylobacter bacteremia is rare and occurs mainly in the elderly with comorbidities. In comparison with Campylobacter infections limited to the gastrointestinal tract, patients with bacteremic Campylobacter infections are older and seem more prone to develop sepsis. Classical gastroenteritis symptoms in bacteremic cases with Campylobacter may be absent.

Campylobacter fetus-induced primary psoas abscess in patient with gouty arthritis: A case report and literature review

RATIONALE

Campylobacter fetus is rare pathogen with high mortality rate in immunosuppressive hosts. This study aimed to summarize clinical and pathological presentation of C fetus induced psoas abscess.

PATIENT CONCERNS

A 66-year-old male patient with long medical history of poorly-controlled gouty arthritis and steroid intake complained of a severe low back pain. Physical examination showed tenderness in his psoas.

DIAGNOSES

The patient underwent puncture biopsy to the lesion in the psoas under ultrasound guidance. The lesion was indicated as abscess by pathological examination, and its pathogen was indicated as C fetus by the next generation sequencing.

INTERVENTIONS

Meropenem 1 g q8.h were administered intravenously for 10 days. Then the antibiotic treatment was switched to amoxicillin/clavulanate potassium 0.375g q.8.h and levofloxacin 0.5g q.d oral administration when discharge.

OUTCOMES

The patient's fever and low back pain improved and infectious parameters declined. He was discharged in good general condition with advice for further monitoring and therapy. In the first month follow-up, the patient did not report recurrence or aggravation of his symptoms.

LESSONS

C fetus should be noticed in immunosuppressive patient with exposure to livestock who present with rare systematic or local invasive infection. We advocated the meropenem for the first-line treatment against C fetus.

Campylobacter coli bacteremia associated with diarrhea

Campylobacter coli (C. coli) is a gram negative, non-spore forming, mobile, curved, or spiral-shaped rod organisms and one of the most common gastrointestinal human pathogens. Campylobacter very rarely causes bacteremia. However, there are reports of bloodstream infection of C. coli and most of the Campylobacterbacteremia have been found among immunocompromised patients. In this study, a case of C. coli blood stream infection that was associated with diarrhea in an immunocompetent patient.

Clinical features and outcomes of bacteremic and non-bacteremic Campylobacteriosis: a case-control study

PURPOSE

Campylobacter bloodstream infection (C-BSI) is uncommon, and its clinical significance is unclear. The aim of the study was to determine risk factors and clinical outcomes associated with Campylobacter BSI.

METHODS

We performed a single center retrospective case-control study comparing patients with C-BSI (cases) and patients with nonbacteremic Campylobacter enteritis (controls), from January 2007 through June 2020. Case and control patients were matched by age and sex at a ratio of 1:2. Demographic, clinical, and microbiological characteristics were compared between groups.

RESULTS

We identified 76 patients with C-BSI and matched them with 149 nonbacteremic patients with Campylobacter enteritis. Rates of C-BSI increased tenfold in 2014 following the introduction of BacTAlert FA/FN Plus blood culture bottles. Baseline variables significantly associated with C-BSI on multivariable logistic regression were fever, absence of diarrhea and recent exposure to antibiotics. Compared with controls, C-BSI was associated with higher 30-day mortality (12% vs. 2%, P = 0.003), more frequent need for intensive care (6.6% vs. 1.2%, P = 0.032) and longer hospital stay (median, 5 days vs. 3 days, P = 0.003). There was a high proportion of immunocompromised patients in both groups (55%).

CONCLUSIONS

C-BSI is identified with increasing frequency, reflecting both changes in epidemiology and improved sensitivity of blood culture systems. Our findings indicate that detection of Campylobacter spp. in blood culture is associated with significantly higher rates of death and other adverse outcomes.

Resistance to Antibiotics in Thermophilic Campylobacters

Campylobacter jejuni (C. jejuni) is one of the most frequent causes of bacterial enterocolitis globally. The disease in human is usually self-limiting, but when complications arise antibiotic therapy is required at a time when resistance to antibiotics is increasing worldwide. Mechanisms of antibiotic resistance in bacteria are diverse depending on antibiotic type and usage and include: enzymatic destruction or drug inactivation; alteration of the target enzyme; alteration of cell membrane permeability; alteration of ribosome structure and alteration of the metabolic pathway(s). Resistance of Campylobacter spp. to antibiotics, especially fluoroquinolones is now a major public health problem in developed and developing countries. In this review the mechanisms of resistance to fluoroquinolones, macrolides, tetracycline, aminoglycoside and the role of integrons in resistance of Campylobacter (especially at the molecular level) are discussed, as well as the mechanisms of resistance to β-lactam antibiotics, sulphonamides and trimethoprim. Multiple drug resistance is an increasing problem for treatment of campylobacter infections and emergence of resistant strains and resistance are important One Health issues.

Bacteraemia, antimicrobial susceptibility and treatment among Campylobacter-associated hospitalisations in the Australian Capital Territory: a review

BACKGROUND

Campylobacter spp. cause mostly self-limiting enterocolitis, although a significant proportion of cases require hospitalisation highlighting potential for severe disease. Among people admitted, blood culture specimens are frequently collected and antibiotic treatment is initiated. We sought to understand clinical and host factors associated with bacteraemia, antibiotic treatment and isolate non-susceptibility among Campylobacter-associated hospitalisations.

METHODS

Using linked hospital microbiology and administrative data we identified and reviewed Campylobacter-associated hospitalisations between 2004 and 2013. We calculated population-level incidence for Campylobacter bacteraemia and used logistic regression to examine factors associated with bacteraemia, antibiotic treatment and isolate non-susceptibility among Campylobacter-associated hospitalisations.

RESULTS

Among 685 Campylobacter-associated hospitalisations, we identified 25 admissions for bacteraemia, an estimated incidence of 0.71 cases per 100,000 population per year. Around half of hospitalisations (333/685) had blood culturing performed. Factors associated with bacteraemia included underlying liver disease (aOR 48.89, 95% CI 7.03-340.22, p < 0.001), Haematology unit admission (aOR 14.67, 95% CI 2.99-72.07, p = 0.001) and age 70-79 years (aOR 4.93, 95% CI 1.57-15.49). Approximately one-third (219/685) of admissions received antibiotics with treatment rates increasing significantly over time (p < 0.05). Factors associated with antibiotic treatment included Gastroenterology unit admission (aOR 3.75, 95% CI 1.95-7.20, p < 0.001), having blood cultures taken (aOR 2.76, 95% CI 1.79-4.26, p < 0.001) and age 40-49 years (aOR 2.34, 95% CI 1.14-4.79, p = 0.02). Non-susceptibility of isolates to standard antimicrobials increased significantly over time (p = 0.01) and was associated with overseas travel (aOR 11.80 95% CI 3.18-43.83, p < 0.001) and negatively associated with tachycardia (aOR 0.48, 95%CI 0.26-0.88, p = 0.02), suggesting a healthy traveller effect.

CONCLUSIONS

Campylobacter infections result in considerable hospital burden. Among those admitted to hospital, an interplay of factors involving clinical presentation, presence of underlying comorbidities, complications and increasing age influence how a case is investigated and managed.

Campylobacter coli bacteraemia: how common is it?

Campylobacter species are known to cause enteritis. However, over the past 40-50 years, there have been reports of varying presentations, such as cellulitis, spondylodiscitis and bacteraemia. Of the Campylobacter species, Campylobacter jejuni is the most common culprit for causing bacteraemia, however, Campylobacter coli bacteraemia is becoming more prevalent. Here, we discuss an unusual case of C. coli bacteraemia in a patient with decompensated liver cirrhosis.

Recurrent Campylobacter Bacteremia as the First Manifestation of Hypogammaglobulinemia: a Case Report and Literature Review

A 30-year-old woman with a past medical history of autoimmune hemolytic anemia presented with fever. Blood cultures grew Campylobacter. Her medical history was significant for four prior episodes of Campylobacter gastroenteritis and bacteremia. She received ciprofloxacin for the index presentation, then Meropenem de-escalated to doxycycline 6 months later following recurrence of Campylobacter. This prompted investigation for an immunodeficiency disorder. She was found to have hypogammaglobulinemia. Her Campylobacter infections resolved following the administration of intravenous immunoglobulins every 3 weeks. She did not have recurrence of Campylobacter during 5 years of follow-up. A literature search revealed additional four case reports of six hypogammaglobulinemic adult individuals presenting with recurrent Campylobacter infections. Three patients were already on intravenous immunoglobulin (IVIG) when Campylobacter infection occurred, and two patients achieved clinical cure following therapy with imipenem and IVIG. This case report highlights the importance of suspecting hypogammaglobulinemia in patients with recurrent Campylobacter infections, as this is sometimes the first manifestation of the condition.

Campylobacter jejuni bacteremia in a patient with asplenia and enteritis

Campylobacter bacteremia is an unusual presentation of a common infectious disease such as enteritis. We provide key teaching points about its presentation, risk factors, diagnosis and treatment.

Campylobacter fetus spondylodiscitis: A case report and review of the literature

Campylobacter are common zoonotic food borne pathogens but infrequent causes of disseminated human infection. Campylobacter fetus is an unusual cause of human infection and spondylodiscitis. We describe a case of C. fetus infection in a 72-year-old woman who presented with indolent onset lumbar spondylodiscitis. The literature is reviewed and the presentation of spondylodiscitis is contrasted with the usual aggressive nature of bacteremia with this pathogen.

Campylobacter bacteremia in London: A 44-year single-center study

PURPOSE

Campylobacter species are a well-recognized but rare cause of bloodstream infection.

METHODS

Here we reviewed 41 cases of Campylobacter bloodstream infection occurring at a single center in London over 44years, comprising 0.2% of all recorded episodes during this time period.

RESULTS

Patients had a mean age of 46years and, contrasting with previous reports, nearly 50% of our patients did not have significant comorbidities. Ciprofloxacin resistance increased over the study period with 35% of isolates overall being resistant compared with only 3% exhibiting macrolide resistance. Despite a minority of patients receiving appropriate empirical antibiotic therapy, overall mortality was only 7%.

CONCLUSION

Campylobacter bacteremia remains a rare but significant cause of morbidity with a low associated mortality. Underlying immunosuppressive conditions are common but by no means universal. In our setting, macrolides would be favored as empirical agents to treat suspected Campylobacter enteritis, including cases with associated bacteremia.

Recurrent Campylobacter jejuni bacteremia in a patient with hypogammaglobulinemia: A case report

RATIONALE

Although some cases of recurrent bacteremia due to Campylobacter jejuni have been reported in immunocompromised patients, antibiotic treatment strategies to eradicate C. jejuni and prevent recurrent infections in immunocompromised patients have not been established. Authors' experience of such rare cases should be shared for improving patients' outcomes.

PATIENT CONCERNS

An 18-year-old boy with hypogammaglobulinemia, who received intravenous immunoglobulin replacement therapy every 3 weeks, was admitted to hospital repeatedly due to recurrent diarrhea and cellulitis of the leg.

DIAGNOSES

The patient was admitted 6 times, and among them, C. jejuni was isolated from blood cultures 4 times and stool cultures 2 times.

INTERVENTIONS

The patient experienced recurrent C. jejuni enteritis and bacteremia 5 times despite macrolide therapy. Doxycycline was administered for 3 months after the fifth admission.

OUTCOMES

Ten months after the completion of doxycycline therapy for 3 months, C. jejuni enteritis relapsed; however, since then, recurrent infection has not occurred for 10 months.

LESSONS

Immunocompromised patients can experience recurrent C. jejuni infection despite prolonged antibiotic therapy. Further studies to establish appropriate antibiotic therapy for eradicating colonized C. jejuni and preventing recurrent infection are needed.

Myositis Ossificans of the Hip Due to Pyogenic Arthritis Caused by Campylobacter fetus Subspecies fetus

A 61-year-old woman was admitted with severe hip pain causing immobility and high serum levels of inflammatory markers. The patient had a medical history of diabetes. She had been scheduled to undergo right hip replacement surgery for the treatment of osteoarthritis associated with gradually progressive pain. On admission, an enhanced abdominal computed tomography scan showed an abnormal increase in synovial fluid surrounding the right ilium, with piriformis muscle calcification. Subsequent blood and specimen cultures identified Campylobacter fetus subspecies fetus. This is a rare report of a case of myositis ossificans followed by C. fetus pyogenic arthritis of the hip.

Campylobacter jejuni Bacteremia in a Patient With Acute Lymphocytic Leukemia

INTRODUCTION

Campylobacter jejuni is a slender, motile, non-spore-forming, helical-shaped, gram-negative bacterium. It is one of the most common causes of human gastroenteritis in the world. The aim of this study was to present a patient with acute lymphocytic leukemia (ALL), who was infected with Campylobacter jejuni.

CASE PRESENTATION

We describe the medical records of a pediatric ALL patient with bacteremia caused by C. jejuni, who was diagnosed at Amir hospital, Shiraz, Iran. This 14-year-old male visited the emergency department of Amir hospital with night sweats, severe polar high-grade fever, reduced appetite, and nausea in August 2013. Given the suspected presence of an anaerobic or microaerophilic microorganism, aerobic and anaerobic blood cultures were performed using an automated blood cultivator, the BACTEC 9240 system. In order to characterize the isolate, diagnostic biochemical tests were used. Antibiotic susceptibility testing was done with the disk diffusion method. The primary culture was found to be positive for Campylobacter, and the subculture of the solid plate yielded a confluent growth of colonies typical for Campylobacter, which was identified as C. jejuni by morphological and biochemical tests. The isolate was resistant to ciprofloxacin, cefotaxime, cephalexin, piperacillin/tazobactam, nalidixic acid, aztreonam, cefuroxime, cefixime, ceftazidime, and tobramycin.

CONCLUSIONS

C. jejuni should be considered in the differential diagnosis as a potential cause of bacteremia in immunosuppressed patients. In cases where the BACTEC result is positive in aerobic conditions but the organism cannot be isolated, an anaerobic culture medium is suggested, especially in immunocompromised patients.

A case of defibrillator-associated infective endocarditis due to Campylobacter fetus

Campylobacter spp. are Gram-negative, spiral motile bacteria. Infections caused by Campylobacter fetus are frequently of invasive character, but they are very rare. The described case of infection of a cardioverter defibrillator implantation site was effectively cured with antibiotics, but it required removal of the cardioverter defibrillator.

Clinical relevance of infections with zoonotic and human oral species of Campylobacter

Genus Campylobacter has been recognized as a causative bacterial agent of animal and human diseases. Human Campylobacter infections have caused more concern. Campylobacters can be classified into two groups in terms of their original host: zoonotic and human oral species. The major zoonotic species are Campylobacter jejuni and Campylobacter coli, which mostly reside in the intestines of avian species and are transmitted to humans via consumption of contaminated poultry products, thus causing human gastroenteritis and other diseases as sequelae. The other campylobacters, human oral species, include C. concisus, C. showae, C. gracilis, C. ureolyticus, C. curvus, and C. rectus. These species are isolated from the oral cavity, natural colonization site, but have potential clinical relevance in the periodontal region to varying extent. Two species, C. jejuni and C. coli, are believed to be mainly associated with intestinal diseases, but recent studies suggested that oral Campylobacter species also play a significant role in intestinal diseases. This review offers an outline of the two Campylobacter groups (zoonotic and human oral), their virulence traits, and the associated illnesses including gastroenteritis.

Campylobacter bacteraemia: 16 years of experience in a single centre

BACKGROUND

Campylobacter bacteraemia (CB) is rare and usually occurs in immune-compromised patients. In this study we examined the incidence and epidemiology of CB in one institution over 15.5 years.

METHODS

The medical records of all the consecutive patients with CB admitted to our hospital from 2000 to 2015 were retrospectively reviewed. Clinical characteristics, microbiologic and outcome data were collected.

RESULTS

During the study period, 65 patients with CB were identified. The majority of the patients were middle aged and immune-compromised. Campylobacter jejuni was the most commonly identified species (33/47, 70%). The main underlying conditions were haematological malignancies (43%) and chronic liver disease (14%). Fifty-seven percent of the patients were receiving immunosuppressive therapy at the time of bacteraemia. The most common presenting symptoms were fever (85%), diarrhoea (40%), abdominal pain (40%), and nausea and vomiting (40%). Of the isolates tested, 97% were susceptible to macrolides, and only 35% were susceptible to quinolones. Susceptibility to quinolones decreased over the years. Most patients did not receive adequate empiric antibiotic treatment (81.5%) and about 20% never received directed therapy. Mortality and relapse rates were low (5% each). There was no association between adequate empirical or definitive antibiotic therapy and adverse outcomes.

CONCLUSION

The main predisposing factor for Campylobacter bacteraemia in our cohort was immunosuppression. Prognosis was generally favourable regardless of appropriateness of antibiotic therapy.

Potential Use of Fosfomycin-Tromethamine for Treatment of Recurrent Campylobacter Species Enteritis

We report 2 cases of recurrent Campylobacter coli enteritis caused by macrolide- and fluoroquinolone-resistant strains in 2 patients with hypogammaglobulinemia, successfully treated with a prolonged course of fosfomycin-tromethamine with no side effects. Fosfomycin-tromethamine may be a feasible alternative therapy for recurrent enteritis caused by Campylobacter species resistant to first-line drugs.

Clinical and epidemiological analysis of Campylobacter fetus subsp. fetus infections in humans and comparative genetic analysis with strains isolated from cattle

Background

Campylobacter fetus subspecies fetus (CFF) is an important pathogen for both cattle and humans. We performed a systematic epidemiological and clinical study of patients and evaluated the genetic relatedness of 17 human and 17 bovine CFF isolates by using different genotyping methods. In addition, the serotype, the dissemination of the genomic island containing a type IV secretion system (T4SS) and resistance determinants for tetracycline and streptomycin were also evaluated.

Methods

The isolates from patients diagnosed with CFF infection as well as those from faecal samples of healthy calves were genotyped using pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), as well as single locus sequence typing (SLST) targeting cmp1 and cmp2 genes encoding two major outer membrane proteins in CFF. The presence of the genomic island and identification of serotype was determined by PCRs targeting genes of the T4SS and the sap locus, respectively. Tetracycline and streptomycin resistance phenotypes were determined by minimal inhibitory concentration. Clinical data obtained from medical records and laboratory data were supplemented by data obtained via telephone interviews with the patients and treating physicians.

Results

PFGE analysis defined two major clusters; cluster A containing 16 bovine (80 %) isolates and cluster B containing 13 human (92 %) isolates, suggesting a host preference. Further genotypic analysis using MLST, SLST as well as sap and T4SS PCR showed the presence of genotypically identical isolates in cattle and humans. The low diversity observed within the cmp alleles of CFF corroborates the clonal nature of this pathogen. The genomic island containing the tetracycline and streptomycin resistance determinants was found in 55 % of the isolates in cluster A and correlated with phenotypic antibiotic resistance.

Conclusions

Most human and bovine isolates were separated on two phylogenetic clusters. However, several human and bovine isolates were identical by diverse genotyping methods, indicating a possible link between strains from these two hosts.

Global Epidemiology of Campylobacter Infection

Campylobacter jejuni infection is one of the most widespread infectious diseases of the last century. The incidence and prevalence of campylobacteriosis have increased in both developed and developing countries over the last 10 years. The dramatic increase in North America, Europe, and Australia is alarming, and data from parts of Africa, Asia, and the Middle East indicate that campylobacteriosis is endemic in these areas, especially in children. In addition to C. jejuni, there is increasing recognition of the clinical importance of emerging Campylobacter species, including Campylobacter concisus and Campylobacter ureolyticus. Poultry is a major reservoir and source of transmission of campylobacteriosis to humans. Other risk factors include consumption of animal products and water, contact with animals, and international travel. Strategic implementation of multifaceted biocontrol measures to reduce the transmission of this group of pathogens is paramount for public health. Overall, campylobacteriosis is still one of the most important infectious diseases that is likely to challenge global health in the years to come. This review provides a comprehensive overview of the global epidemiology, transmission, and clinical relevance of Campylobacter infection.

Prevalence, Antimicrobial Resistance and Risk Factors for Thermophilic Campylobacter Infections in Symptomatic and Asymptomatic Humans in Tanzania

The genus Campylobacter comprises members known to be a leading cause of foodborne gastrointestinal illness worldwide. A study was conducted to determine the epidemiology and antimicrobial resistance of Campylobacter in humans in Morogoro, Eastern Tanzania. Isolation of Campylobacter from stool specimens adopted the Cape Town protocol. Campylobacter isolates were preliminarily identified by conventional phenotypic tests and subsequently confirmed by matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) mass spectrometry and polymerase chain reaction. Antimicrobial resistance testing employed the disc diffusion method. A small proportion of the test isolates was also subjected to agar dilution method. Risk factors for human illness were determined in an unmatched case-control study. Thermophilic Campylobacter were isolated from 11.4% of the screened individuals (n = 1195). The agreement between PCR and MALDI-TOF was perfect (κ = 1.0). Symptomatics and young individuals were infected with higher numbers than asymptomatic and adults, respectively. The majority (84.6%) of the isolates were C. jejuni and the remaining were C. coli. Isolates had highest resistance (95.6%) for colistin sulphate and lowest for ciprofloxacin (22.1%). The rates of resistance for other antibiotics (azithromycin, erythromycin, tetracycline, cephalothin, gentamycin, nalidixic acid, ampicillin, amoxycillin, norfloxacin, chloramphenicol) ranged from 44.1% to 89%. Comparison between disc diffusion and agar dilution methods indicated a good correlation, and the tests were in agreement to each other (κ ≥ 0.75). Human illness was found to be associated with young age and consumption of chicken meat and pre-prepared salad. Our data indicate the presence of antibiotic-resistant thermophilic Campylobacter in humans in the study area. There is a need for routine investigation of the presence of the organisms in gastroenteritis aetiology, including determination of their antibiotic susceptibilities.

The role of serine protease HtrA in acute ulcerative enterocolitis and extra-intestinal immune responses during Campylobacter jejuni infection of gnotobiotic IL-10 deficient mice

Campylobacter jejuni infections have a high prevalence worldwide and represent a significant socioeconomic burden. C. jejuni can cross the intestinal epithelial barrier as visualized in biopsies derived from human patients and animal models, however, the underlying molecular mechanisms and associated immunopathology are still not well understood. We have recently shown that the secreted serine protease HtrA (high temperature requirement A) plays a key role in C. jejuni cellular invasion and transmigration across polarized epithelial cells in vitro. In the present in vivo study we investigated the role of HtrA during C. jejuni infection of mice. We used the gnotobiotic IL-10^−/− mouse model to study campylobacteriosis following peroral infection with the C. jejuni wild-type (WT) strain NCTC11168 and the isogenic, non-polar NCTC11168ΔhtrA deletion mutant. Six days post infection (p.i.) with either strain mice harbored comparable intestinal C. jejuni loads, whereas ulcerative enterocolitis was less pronounced in mice infected with the ΔhtrA mutant strain. Moreover, ΔhtrA mutant infected mice displayed lower apoptotic cell numbers in the large intestinal mucosa, less colonic accumulation of neutrophils, macrophages and monocytes, lower large intestinal nitric oxide, IFN-γ, and IL-6 as well as lower TNF-α and IL-6 serum concentrations as compared to WT strain infected mice at day 6 p.i. Notably, immunopathological responses were not restricted to the intestinal tract given that liver and kidneys exhibited mild histopathological changes 6 days p.i. with either C. jejuni strain. We also found that hepatic and renal nitric oxide levels or renal TNF-α concentrations were lower in the ΔhtrA mutant as compared to WT strain infected mice. In conclusion, we show here that the C. jejuni HtrA protein plays a pivotal role in inducing host cell apoptosis and immunopathology during murine campylobacteriosis in the gut in vivo.

The impact of serine protease HtrA in apoptosis, intestinal immune responses and extra-intestinal histopathology during Campylobacter jejuni infection of infant mice

Background

Campylobacter jejuni has emerged as a leading cause of bacterial enterocolitis. The serine protease HtrA has been shown to be a pivotal, novel C. jejuni virulence factor involved in cell invasion and transmigration across polarised epithelial cells in vitro. However, the functional relevance of the htrA gene for the interaction of C. jejuni with the host immune system in the infant mouse infection model has not been investigated so far.

Results

Here we studied the role of C. jejuni htrA during infection of 3-weeks-old infant mice. Immediately after weaning, conventional wild-type mice were perorally infected with the NCTC11168∆htrA mutant (∆htrA) or the parental wild-type strain. Approximately one third of infected infant mice suffered from bloody diarrhea until day 7 post infection (p.i.), whereas colonic histopathological changes were rather moderate but comparable between the two strains. Interestingly, parental, but not ∆htrA mutant infected mice, displayed a multifold increase of apoptotic cells in the colonic mucosa at day 7 p.i., which was paralleled by higher colonic levels of pro-inflammatory cytokines such as TNF-α and IFN-γ and the matrix-degrading enzyme matrixmetalloproteinase-2 (MMP-2). Furthermore, higher numbers of proliferating cells could be observed in the colon of ∆htrA infected mice as compared to the parental wild-type strain. Remarkably, as early as 7 days p.i. infant mice also exhibited inflammatory changes in extra-intestinal compartments such as liver, kidneys and lungs, which were less distinct in kidneys and lungs following ∆htrA versus parental strain infection. However, live C. jejuni bacteria could not be found in these organs, suggesting the induction of systemic effects during intestinal infection.

Conclusion

Upon C. jejuni ∆htrA strain infection of infant mice, intestinal and extra-intestinal pro-inflammatory immune responses were ameliorated in the infant mouse model system. Future studies will shed further light onto the molecular mechanisms of host-pathogen interactions.

Demographic and clinical characteristics of Campylobacter bacteremia in children with and without predisposing factors

BACKGROUND

Campylobacter, a common cause of childhood gastroenteritis, rarely causes bacteremia, which is reported mainly in immune-compromised children. Our aim was to compare demographic and clinical characteristics of childhood campylobacter bacteremia (CB) between children with and without risk factors for CB.

METHODS

A retrospective, population-based study, conducted between 1989 and 2010. Risk factors were defined as immunodeficiency, malignancy, extreme prematurity or chronic diseases with malnutrition.

RESULTS

Seventy-six CB episodes (1 per child/month) were identified in 14 children with risk factors (30 episodes) and 46 children without risk factors (46 episodes). Children with risk factors were older (mean age 120.0±72.8 vs. 16.2±27.6 months) with higher proportion of males (90.0% vs. 60.9%), less gastrointestinal symptoms (43.3% vs. 69.9%) and higher hospitalization rates (96.7% vs. 69.6%) compared with children without risk factors. Campylobacter jejuni and Campylobacter coli (46/47 of identified species) were the most common species in both groups. Positive campylobacter stool cultures were found only in children without risk factors (0% vs. 38.5%). No mortality cases were observed. All isolates tested for antibiotic susceptibility were sensitive to macrolides and carbapenems.

CONCLUSIONS

Childhood CB is rare in southern Israel. The disease manifests as a single gastroenteritis complication in a previously healthy young child or as recurrent episodes in an older, immune-compromised child, usually without gastrointestinal symptoms. This disparity may reflect pathogenesis differences, with disease in the immune-competent being dependent on pathogen virulence, whereas disease in the immune-compromised being host dependent. Disease outcome is usually favorable, and macrolides remain the antibiotic treatment of choice.

Survey of extra-intestinal immune responses in asymptomatic long-term Campylobacter jejuni-infected mice

Campylobacter jejuni is among the most frequently reported bacterial pathogens causing diarrhea in humans worldwide. We recently reported a murine infection model mimicking key features of human campylobacteriosis. Six days following oral C. jejuni infection immediately after weaning, infant mice developed acute enterocolitis resolving within 2 weeks. Thereafter, C. jejuni could still be isolated from the intestines of asymptomatic mice at low levels accompanied by distinct immune responses, both at intestinal and extra-intestinal locations. We here show that, at day 103 post infection (p.i.), long-term C. jejuni-infected mice exhibited higher numbers of T lymphocytes in liver, lung, kindneys, and cardiac muscle as compared to uninfected controls. In addition, B lymphocytes were slightly higher, but macrophage numbers were significantly lower in liver and lung of C. jejuni-infected versus naive mice. As compared to uninfected control animals, proliferating cells were significantly lower in liver, lung, kidneys, cardiac muscle, and spleen at day 103 p.i., whereas more apoptotic cells were abundant in the spleen with predominance in the red pulp. This study underlines that post-infectious, immunological sequelae at extra-intestinal locations are of importance even in asymptomatic long-term C. jejuni carriers and need to be further studied in order to unravel the underlying molecular mechanisms.

Impact and management of Campylobacter in human medicine--US perspective

Viruses, enteric bacteria and parasites can all produce similar syndromes of acute enteritis, although the pathophysiology and molecular pathogenesis may vary widely. The severity of acute enteritis varies greatly, and only a small fraction of cases undergo medical evaluation. There are over 200 000 000 episodes of acute enteritis annually in the USA, of which approximately 75 000 000 are foodborne. Fewer than 20% of estimated cases have a known etiology. Nearly half of the more than 4 000 000 cases of known foodborne bacterial enteritis are attributed to Campylobacter infections. The FoodNet active population-based surveillance system has demonstrated geographic variation in the incidence of Campylobacter infection, and generally declining incidence since 1996. Campylobacter jejuni infections vary in severity and duration. Antimicrobial therapy, especially if administered early, may hasten clinical resolution by 2-3 days. Therapy is generally restricted to individuals with moderate-to-severe disease and high-risk individuals (underlying immunodeficiency, chronic illness, extremes of age, etc.). Approximately 10-15% of C. jejuni isolates are fluoroquinolone resistant, although most strains are macrolide susceptible. Several acute intra-abdominal as well as extraintestinal complications can occur following C jejuni enteritis, although bacteremia and metastatic infection are rare, except in high-risk patients. Post-infectious syndromes include post-dysenteric bowel dysfunction, the less frequent but more severe reactive arthritis (1%), and Guillain-Barre syndrome (0.1%). The recent demonstration that antibiotic administration for Escherichia coli O157:H7 hemorrhagic enteritis increases the risk of hemolytic-uremic syndrome 5-10-fold forces reconsideration of empirical broad-spectrum antibiotic therapy for acute hemorrhagic enteritis, and supports narrow-spectrum erythromycin therapy for acute enteritis.

Effects of lipooligosaccharide inner core truncation on bile resistance and chick colonization by Campylobacter jejuni

Campylobacter jejuni is the most common bacterium that causes diarrhea worldwide, and chickens are considered the main reservoir of this pathogen. This study investigated the effects of serial truncation of lipooligosaccharide (LOS), a major component of the outer membrane of C. jejuni, on its bile resistance and intestinal colonization ability in chickens. Genes encoding manno-heptose synthetases or glycosyltransferases were inactivated to generate isogenic mutants. Serial truncation of the LOS core oligosaccharide caused a stepwise increase in susceptibilities of two C. jejuni strains, NCTC 11168 and 81-176, to bile acids. Inactivation of hldE, hldD, or waaC caused severe truncation of the core oligosaccharide, which greatly increased the susceptibility to bile acids. Both wild-type strains grew normally in chicken intestinal extracts, whereas the mutants with severe oligosaccharide truncation were not detected 12 h after inoculation. These mutants attained viable bacterial counts in the bile acid-free extracts 24 h after inoculation. The wild-type strain 11-164 was present in the cecal contents at >10(7) CFU/g on 5 days after challenge infection and after this time period, whereas its hldD mutant was present at <10(3) CFU/g throughout the experimental period. Trans-complementation of the hldD mutant with the wild-type hldD allele completely restored the in vivo colonization level to that of the wild-type strain. Mutants with a shorter LOS had higher hydrophobicities. Thus, the length of the LOS core oligosaccharide affected the surface hydrophobicity and bile resistance of C. jejuni as well as its ability to colonize chicken intestines.

An unusual cause of spontaneous bacterial peritonitis due to Campylobacter fetus with alcoholic liver cirrhosis

A 40-year-old man with severe alcoholic liver cirrhosis with a 2-day history of fatigue and abdominal pain was admitted. He reported eating sushi and sliced raw chicken a few days previously. His abdomen was distended, with shifting dullness. Based on the patient's history, physical examination and the results of abdominocentesis, he was diagnosed as having spontaneous bacterial peritonitis; blood and ascitic fluid cultures were positive for Campylobacter fetus. The patient was started on treatment with cefotaxime, which was switched after 1 week to ampicillin for an additional 3 weeks. The patient was successfully treated with the 4-week course of intravenous antibiotic therapy.

Campylobacter fetus infection presenting with bacteremia and cellulitis in a 72-year-old man with an implanted pacemaker: a case report

INTRODUCTION

Campylobacter is an important causative agent of intestinal infections in humans. Bacteremia is detected in less than 1% of patients, mainly in immunocompromised patients and in extreme age groups. Cellulitis is a relatively common manifestation of Campylobacter infection, but concomitant bacteremia is a rare event. Infections of the pacemaker area are caused primarily by staphylococci, followed by fungi, streptococci and Gram-negative rods. To the best of our knowledge, this is the first case report of pacemaker pocket infection and bacteremia caused by Campylobacter fetus.

CASE PRESENTATION

A 72-year-old Croatian Caucasian man with myelodysplasia, impaired fasting glucose levels and a recently implanted permanent pacemaker was admitted to hospital after six days of fever, development of red swelling of the pacemaker pocket area and worsening of his general condition. No antibiotic therapy was introduced in the outpatient setting. He denied any recent gastrointestinal disturbances. With the exception of an elevated leukocyte count, erythrocyte sedimentation rate, and C-reactive protein and blood glucose levels, other laboratory findings were normal. Treatment with vancomycin plus netilmicin was introduced, and a surgical incision with drainage of the pacemaker pocket was performed. The entire pacemaker system was removed and a new one re-implanted after 14 days of antibiotic therapy. Transesophageal echocardiography showed no pathological findings. Three subsequent blood cultures obtained on admission as well as swab culture of the incised pacemaker area revealed Campylobacter fetus; stool and pacemaker lead cultures were negative. According to the microbiological results, antibiotic therapy was changed to ciprofloxacin plus netilmicin. A clinical examination and the results of a laboratory analysis performed after two weeks of therapy were within normal limits.

CONCLUSION

Myelodysplasia, impaired fasting glucose levels and older age could be contributing factors for the development of bacteremic Campylobacter fetus cellulitis. Emergent surgical and antibiotic treatment are mandatory and provide the optimal outcome for such types of pacemaker pocket infection.

Bacteremia caused by antimicrobial resistant Campylobacter species at a medical center in Taiwan, 1998-2008

OBJECTIVES

This study was intended to delineate the clinical and microbiological characteristics of patients with bacteremia caused by Campylobacter species.

METHODS

Twenty-four patients with Campylobacter bacteremia were treated at the National Taiwan University Hospital from 1998 to 2008. All isolates from the 24 patients were confirmed to the species level by multiplex PCR (cadF, hipO and asp gene) and 16S RNA gene sequencing.

RESULTS

Bacteremia was caused by Campylobacter coli in 15 (62.5%) patients, Campylobacter fetus in 6 (25%), and Campylobacter jejuni in 3 (12.5%). Of the 24 patients, 16 were male. The major underlying conditions included chronic renal insufficiency (41.7%), liver cirrhosis (37.5%), malignancy (33.3%), and previous abdominal surgery (33.3%). The most common infections were intra-abdominal infection (54.2%), followed by primary bacteremia (41.7%), and cellulitis (4.2%). The mean Pittsburgh bacteremia score was 2.5 (range, 0-9). During the bacteremic episodes, six (25%) patients developed septic shock. Third-generation cephalosporins were administered to 12 (50%) patients as empirical therapy. All-cause mortality was 4.2% at 14 days and 12.5% at 30 days. The majority of the isolates were resistant to third-generation cephalosporins and quinolones, with minimum inhibitory concentration (MIC(90)) values of 32 mg/L for cefotaxime, 128 mg/L for ceftriaxone, and 32 mg/L for both ciprofloxacin and levofloxacin. All isolates possessed a parC mutation (Arg-139-Gln) and 15 exhibited an additional gyrA mutation (Thr-86-Ile). Among these isolates, 20.8% were susceptible to erythromycin (MIC≤0.5 mg/L).

CONCLUSION

Bacteremia caused by antimicrobial resistant Campylobacter species is alarming although the mortality rate is low.

Bacterial infections other than spontaneous bacterial peritonitis in cirrhosis

Cirrhotic patients are immunocompromised with a high risk of infection. Proinflammatory cytokines and hemodynamic circulation derangement further facilitate the development of serious consequences of infections. Other than spontaneous bacterial peritonitis, bacteremia and bacterial infections of other organ systems are frequently observed. Gram-negative enteric bacteria are the most common causative organism. Other bacterial infections, such as enterococci, Vibrio spp., Aeromonas spp., Clostridium spp., Listeria monocytogenes, Plesiomonas shigelloides and Mycobacterium tuberculosis are more prevalent and more virulent. Generally, intravenous third generation cephalosporins are recommended as empirical antibiotic therapy. Increased incidences of gram-positive and drug-resistant organisms have been reported, particularly in hospital-acquired infections and in patients receiving quinolones prophylaxis. This review focuses upon epidemiology, microbiology, clinical features and treatment of infections in cirrhosis other than spontaneous bacterial peritonitis, including pathogen-specific and liver disease-specific issues.

So close and yet so far - Molecular Microbiology of Campylobacter fetus subspecies

Campylobacter fetus comprises two subspecies, C. fetus subsp. fetus and C. fetus subsp. venerealis, which are considered emerging pathogens in humans and animals. Comparisons at the genome level have revealed modest subspecies-specific variation; nevertheless, these two subspecies show distinct host and niche preferences. C. fetus subsp. fetus is a commensal and pathogen of domesticated animals that can be transmitted to humans via contaminated food. The clinical features of human infection can be severe, especially in impaired hosts. In contrast, C. fetus subsp. venerealis is a sexually transmitted pathogen essentially restricted to cattle. Infections leading to bovine venereal campylobacteriosis cause substantial economic losses due to abortion and infertility. Recent genome sequencing of the two subspecies has advanced our understanding of C. fetus adaptations through comparative genomics and the identification of subspecies-specific gene regions predicted to be involved in pathogenesis. The most striking difference between the subspecies is the highly subspecies-specific association of a pathogenicity island in the C. fetus subsp. venerealis chromosome. The inserted region encodes a Type 4 secretion system, which contributes to virulence properties of this organism in vitro. This review describes the main differences in epidemiological, phenotypic, and molecular characteristics of the two subspecies and summarizes recent advances towards understanding the molecular mechanisms of C. fetus pathogenesis.

Campylobacter bacteremia: a rare and under-reported event?

Bacteria belonging to the species Campylobacter are the most common cause of bacterial diarrhoea in humans. The clinical phenotype associated with Campylobacter infections ranges from asymptomatic conditions to severe colitis and bacteremia. In susceptible patients, Campylobacter infections are associated with significant morbidity and mortality, with both host factors and bacterial factors being involved in the pathogenesis of bacteremia. In the host, age, gender and immune-compromising conditions may predispose for Campylobacter infections, whilst the most important bacterial determinants mentioned in the literature are cytotoxin production and flagellar motility. The role of sialylated lipo-oligosaccharide (LOS) and serum resistance in bacteremia is inconclusive at this time, and the clinical significance of Campylobacter bacteremia is not yet fully understood. More emphasis on the detection of Campylobacter species from blood cultures in susceptible patients at risk for Campylobacter infections will increase our understanding of the pathogenesis and the relevance of Campylobacter bacteremia.

The clinical importance of emerging Campylobacter species

A growing number of Campylobacter species other than C. jejuni and C. coli have been recognized as emerging human and animal pathogens. Although C. jejuni continues to be the leading cause of bacterial gastroenteritis in humans worldwide, advances in molecular biology and development of innovative culture methodologies have led to the detection and isolation of a range of under-recognized and nutritionally fastidious Campylobacter spp., including C. concisus, C. upsaliensis and C. ureolyticus. These emerging Campylobacter spp. have been associated with a range of gastrointestinal diseases, particularly gastroenteritis, IBD and periodontitis. In some instances, infection of the gastrointestinal tract by these bacteria can progress to life-threatening extragastrointestinal diseases. Studies have shown that several emerging Campylobacter spp. have the ability to attach to and invade human intestinal epithelial cells and macrophages, damage intestinal barrier integrity, secrete toxins and strategically evade host immune responses. Members of the Campylobacter genus naturally colonize a wide range of hosts (including pets, farm animals and wild animals) and are frequently found in contaminated food products, which indicates that these bacteria are at risk of zoonotic transmission to humans. This Review presents the latest information on the role and clinical importance of emerging Campylobacter spp. in gastrointestinal health and disease.

Contribution of TAT system translocated PhoX to Campylobacter jejuni phosphate metabolism and resilience to environmental stresses

Campylobacter jejuni is a common gastrointestinal pathogen that colonizes food animals; it is transmitted via fecal contamination of food, and infections in immune-compromised people are more likely to result in serious long-term illness. Environmental phosphate is likely an important sensor of environmental fitness and the ability to obtain extracellular phosphate is central to the bacteria's core metabolic responses. PhoX is the sole alkaline phosphatase in C. jejuni, a substrate of the TAT transport system. Alkaline phosphatases mediate the hydrolytic removal of inorganic phosphate (Pi) from phospho-organic compounds and thereby contribute significantly to the polyphosphate kinase 1 (ppk1) mediated formation of poly P, a molecule that regulates bacterial response to stresses and virulence. Similarly, deletion of the tatC gene, a key component of the TAT system, results in diverse phenotypes in C. jejuni including reduced stress tolerance and in vivo colonization. Therefore, here we investigated the contribution of phoX in poly P synthesis and in TAT-system mediated responses. The phoX deletion mutant showed significant decrease (P<0.05) in poly P accumulation in stationary phase compared to the wild-type, suggesting that PhoX is a major contributor to the inorganic phosphate pool in the cell which is essential for poly P synthesis. The phoX deletion is sufficient for a nutrient stress defect similar to the defect previously described for the ΔtatC mutant. Additionally, the phoX deletion mutant has increased resistance to certain antimicrobials. The ΔphoX mutant was also moderately defective in invasion and intracellular survival within human intestinal epithelial cells as well as in chicken colonization. Further, the ΔphoX mutant produced increased biofilm that can be rescued with 1 mM inorganic phosphate. The qRT-PCR of the ΔphoX mutant revealed transcriptional changes that suggest potential mechanisms for the increased biofilm phenotype.

A nationwide study of Campylobacter jejuni and Campylobacter coli bacteremia in Finland over a 10-year period, 1998-2007, with special reference to clinical characteristics and antimicrobial susceptibility

BACKGROUND

Campylobacter bacteremia is an uncommon condition, usually diagnosed in elderly and immunocompromised patients.

METHODS

Blood culture isolates and clinical information were collected for patients with diagnoses of Campylobacter jejuni or Campylobacter coli bacteremia in Finland from 1998 through 2007. Bacterial species were identified by means of polymerase chain reaction analysis, and minimal inhibitory concentrations for ciprofloxacin, clindamycin, doxycycline, erythromycin, gentamicin, meropenem, and metronidazole were determined with an agar dilution method. Medical records and mortality data within 1 year after the bacteremic episode were reviewed.

RESULTS

The study included 76 patients (median age, 46 years), for whom bacterial isolates (C. jejuni in 73, C. coli in 3) and clinical information were available. Most patients (70%) had no significant underlying diseases. The majority (82%) of the isolates were susceptible for all antimicrobial agents tested. However, antimicrobial therapy seemed to have only a limited effect, because no differences could be detected between patients with appropriate empirical antimicrobial treatment and those with delayed appropriate, inappropriate, or no antimicrobial therapy, either in the duration of hospitalization (median, 4 days for both groups) or in attributable mortality. The outcome of the infection was severe in 4 patients infected with C. jejuni; 2 died within 30 days, spondylodiscitis developed in 1, and Guillain-Barré syndrome developed in 1.

CONCLUSIONS

C. jejuni and C. coli bacteremia occurred mainly in moderately young individuals without severe underlying diseases. The bacterial isolates were predominantly susceptible to antimicrobial agents, and the outcome of the disease was typically good, regardless of appropriate or inappropriate antimicrobial treatment given in the hospital.

Aortic homograft endocarditis caused by Campylobacter jejuni

We report the first case of homograft endocarditis caused by Campylobacter jejuni, which was treated successfully with antibiotic therapy and valve replacement. To our knowledge, only two other cases of C. jejuni endocarditis, involving native valves, have been reported in the medical literature.

Acute and chronic histological changes of the small bowel secondary to C. jejuni infection in a rat model for post-infectious IBS

BACKGROUND

Campylobacter jejuni has been implicated in the pathogenesis of post-infectious irritable bowel syndrome (PI-IBS) in humans, effects which may be because of cytolethal distending toxin (CDT). In this study, we characterized both acute and chronic-phase histological changes of the small bowel in rats exposed to wild-type C. jejuni 81-176, or a strain that does not produce CDT, by using a validated rat model of PI-IBS.

METHODS

Sprague-Dawley rats were given 1.0 × 10(8) CFU of either wild-type C. jejuni 81-176 (C+, PI/C+) or the CDT-negative strain (CDT-), or vehicle alone (Control). Acute-phase rats (C+, CDT-) were euthanized on days 2, 4, 8, 16, and 32. Chronic-phase rats (PI/C+, Control) were euthanized 3 months after clearing the initial infection. Segments of duodenum, jejunum, and ileum were resected and the contents plated for C. jejuni culture, and tissue sections were stained for histology.

RESULTS

We observed preferential infection of the ileum and jejunum by Campylobacter jejuni. Compared with controls, epithelial cell basal membrane ballooning, villous tip disruption, and reduced villous-to-crypt ratios were observed for both C+ and CDT- rats. Villous widening, the only result significantly different in C+ vs. CDT- rats, was greatest at day 4 (134.1 ± 21.12 μm vs. 109.9 ± 10.6 μm for CDT-, P < 0.01). Little or no cellular inflammatory changes were seen during acute C. jejuni infection. Three months after clearing the initial infection, no histological changes remained.

CONCLUSION

Significant histological changes, with the absence of inflammatory cells, are seen in the duodenum, jejunum, and ileum of rats during acute infection with C. jejuni. These changes occurred irrespective of the presence or absence of the CDT toxin.

Campylobacter fetus Bacteremia Revealed by Cellulitis without Gastrointestinal Symptoms in the Context of Acquired Hypogammaglobulinemia: A Report of Three Cases

Campylobacter fetus bacteremia is rare and occurs mainly in patients with immunosuppression. This infection, which often involves secondary localizations has already been reported in some primary humoral immune deficiencies. We describe three cases of severe infection due to C. fetus with cellulitis at presentation, but without any gastrointestinal symptoms, occurring in patients with acquired hypogammaglobulinemia.

Campylobacter bacteremia: clinical characteristics, incidence, and outcome over 23 years

Campylobacter is a very rare cause of bloodstream infection, although it has been found relatively frequently in patients infected with human immunodeficiency virus (HIV). The impact of highly active antiretroviral therapy (HAART) and new forms of immunosuppression on the incidence of Campylobacter bacteremia has not been sufficiently assessed. In this study we analyzed the incidence and microbiologic and clinical characteristics of Campylobacter bacteremia over 23 years.We reviewed the clinical records of all patients who had Campylobacter bacteremia from 1985 to 2007. Available strains were reidentified using universal polymerase chain reaction (PCR).During the study period, there were 71 episodes of Campylobacter bacteremia in 63 patients (0.24% of all bloodstream infections), and the incidence remained stable (mean, 0.06/1000 admissions per year and 0.47/100,000 inhabitants per year). Median age was 52 years (interquartile range, 31.25-72.5 yr), and 82% of patients were male. The underlying conditions included liver disease (21/64, 32.8%), HIV infection (15/64, 23.4%), malignancy (7/64, 10.9%), solid organ transplantation (2/64, 3%), hypogammaglobulinemia (10/64, 15.6%), and other (18/64, 31.2%). Twelve patients shared more than 1 underlying condition. Campylobacter bacteremia was community acquired in 81% of the episodes. The origin of the bloodstream infection was abdominal (43.5%), primary (26%), or extraintestinal (31%: respiratory 15%, cellulitis 4.8%, urinary 8%, other 3%). C jejuni was recovered in 66% of cases, C fetus in 19%, and C coli in 12%.Universal PCR was performed on 14 available strains. Molecular and conventional identification matched in 8 isolates. In contrast, molecular methods classified as C fetus (n = 2) and C jejuni (n = 1) 3 strains formerly identified only to genus level as Campylobacter species. In another 3 isolates, molecular identification was not consistent with the phenotypic identification (C fetus identified as C jejuni).Complications appeared in 23.9% of patients. Quinolone resistance was observed in 50% of the isolates. Only 37.8% of patients received appropriate empirical therapy. Mortality was 16.4%, although it was higher in HIV-infected patients than uninfected patients (33% vs. 10%; p = 0.04), in cases of hospital-acquired Campylobacter bacteremia compared with community-acquired cases (38.5% vs. 9.4%; p = 0.02), and in the presence of complications compared with patients without complications (100% vs. 0%; p < 0.001). The incidence of recurrence was 5% (3 patients with humoral immunodeficiency). There was a higher proportion of HIV-infected patients among patients with Campylobacter bacteremia in the pre-HAART era (1985-1996) than in the HAART era (1997-2007)-27.5% (11/40) vs. 14.3% (4/28)-although the difference was not statistically significant. Debilitating diseases such as chronic obstructive pulmonary disease emerged as predisposing conditions in the HAART era (0% before HAART era vs. 14.3% in HAART era; p = 0.032).Campylobacter bacteremia is no longer a significant disease of HIV-positive patients on HAART, but often affects other immunocompromised patients as well. Campylobacter bacteremia has an extraintestinal origin in as many as 31% of cases, and humoral immunodeficiency must be sought in patients with recurrent episodes. Quinolones should not be considered for empirical therapy.

Campylobacter fetus subspecies fetus spondylodiscitis

Campylobacter spp. are common causes of gastrointestinal infections. Campylobacter fetus is a much rarer pathogen in humans, and usually causes bacteraemia and systemic complications in patients with predisposing conditions. We report a case of spondylodiscitis caused by C. fetus subsp. fetus as revealed by vertebral biopsy culture. This identification was confirmed by sequencing the 16S rRNA gene and by phylogenetic analysis. Treatment consisted of 6 weeks antimicrobial therapy combined with a strict initial immobilization, followed by a re-education program. The patient's recovery was uneventful.

Prevalence, antibiograms, and transferable tet(O) plasmid of Campylobacter jejuni and Campylobacter coli isolated from raw chicken, pork, and human clinical cases in Korea

The antibiotic resistance patterns and prevalence of the transferable tet(O) plasmid were investigated in Campylobacter jejuni and Campylobacter coli isolates from raw chicken, pork, and humans with clinical campylobacteriosis. A total of 180 C. jejuni and C. coli isolates were identified, and the prevalence rates of C. jejuni and C. coli in raw chicken samples were 83% (83 of 100) and 73% (73 of 100), respectively. Twelve percent (6 of 50) and 10% (5 of 50) of pork samples were contaminated with C. jejuni and C. coli, respectively. Disk diffusion susceptibility testing revealed that the most frequently detected resistance was to tetracycline (92.2%), followed by nalidixic acid (75.6%), ciprofloxacin (65.0%), azithromycin (41.5%), ampicillin (33.3%), and streptomycin (26.1%). Of the C. jejuni and C. coli isolates, 65.7% (n=109) contained plasmids carrying the tet(O) gene. Six C. jejuni isolates and two C. coli isolates with high-level resistance to tetracycline (MIC=256 microg/ml) harbored the tet(O) plasmid, which is transferable to other C. jejuni and C. coli isolates. These results demonstrate the presence of an interspecies transferable plasmid containing the tet(O) gene and a high prevalence of antibiotic resistance in Korean Campylobacter isolates and provide an understanding of the antibiotic resistance distribution among Campylobacter species in Korea.

Bacteraemia as a result of Campylobacter species: a population-based study of epidemiology and clinical risk factors

Invasive disease as a result of Campylobacter is rarely reported. We reviewed 46 cases of blood stream infection with Campylobacter in a Danish population with complete follow-up. The incidence was 2.9 per 1 million person-years with a peak incidence in the age group above 80 years. In the population, the ratio of notified bacteraemia/enteritis patients with Campylobacter infection was 0.004. Patients with bacteraemia were older and had higher comorbidity, e.g. alcoholism, immunosuppression, previous gastrointestinal surgery or HIV infection. We found 26% of blood isolates resistant to ciprofloxacin. The length of hospitalization was significantly longer in bacteraemia patients, whereas the outcome was favourable with 28-day mortality of 4% in bacteraemia patients and 1% in enteritis patients. None of the bacteraemia patients relapsed within 365-day follow-up.

Spondylodiscitis and an aortic aneurysm due to Campylobacter coli

Campylobacter coli is a rare cause of bacteremia. We report here the first case of C.coli spondylodiscitis complicated by an aortic aneurysm. Outcome was favourable with surgery and antibiotic therapy.