Use of ciprofloxacin for successful eradication of bacteremia due to Campylobacter cinaedi in a human immunodeficiency virus-infected person

Enterohepatic Helicobacter species - clinical importance, host range, and zoonotic potential

The genus Helicobacter defined just over 30 years ago, is a highly diverse and fast-growing group of bacteria that are able to persistently colonize a wide range of animals. The members of this genus are subdivided into two groups with different ecological niches, associated pathologies, and phylogenetic relationships: the gastric Helicobacter (GH) and the enterohepatic Helicobacter (EHH) species. Although GH have been mostly studied, EHH species have become increasingly important as emerging human pathogens and potential zoonotic agents in the last years. This group of bacteria has been associated with the development of several diseases in humans from acute pathologies like gastroenteritis to chronic pathologies that include inflammatory bowel disease, and liver and gallbladder diseases. However, their reservoirs, as well as their routes of transmission, have not been well established yet. Therefore, this review summarizes the current knowledge of taxonomy, epidemiology, and clinical role of the EHH group.

Helicobacter cinaedi-Associated Refractory Cellulitis in Patients with X-Linked Agammaglobulinemia

X-linked agammaglobulinemia (XLA) is characterized by severe or recurrent infections, hypogammaglobulinemia, and circulating B cell deficiency. The frequent pathogens seen in patients with XLA include Streptococcus pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa, and enterovirus as well as Campylobacter and Helicobacter species. Here, we describe two patients with XLA who developed cellulitis and bacteremia caused by Helicobacter cinaedi even when administered an appropriate immunoglobulin replacement therapy. H. cinaedi may be difficult to isolate using a conventional blood culture system and could be identified by sequence analysis and mass spectrometry. H. cinaedi infection causes recurrent symptoms frequently, and patients require a long course of antibiotic treatment. Recently, the case of non-H. pylori Helicobacter (NHPH) infection such as H. cinaedi and H. bilis infection is increasing in number in patients with XLA. Systemic NHPH infection should be suspected, and extensive microbiological analysis should be performed to appropriately treat patients with XLA who present with fever and skin lesions.

Risk Factors for Recurrent Helicobacter cinaedi Bacteremia and the Efficacy of Selective Digestive Decontamination With Kanamycin to Prevent Recurrence

Background

Previous studies suggest that Helicobacter cinaedi can cause recurrent bacteremia. In this study, we elucidated the risk factors for recurrent H. cinaedi bacteremia and explored the efficacy of selective digestive decontamination (SDD) as a preventive measure.

Methods

We retrospectively reviewed the medical records of patients with H. cinaedi bacteremia between March 2009 and December 2016 at 2 Japanese hospitals.

Results

We identified 168 patients with H. cinaedi bacteremia. Bacteremia recurred in 34 patients. The 100-day cumulative incidence rate of recurrent bacteremia was 18.7%. In univariate analysis of factors associated with recurrent bacteremia, anticancer chemotherapy (hazard ratio [HR], 3.75; 95% confidence interval [CI], 1.86-7.58; P < .001), systemic steroids (HR, 3.79; 95% CI, 1.70-8.45; P = .0011), and hematological malignancy (HR, 3.18; 95% CI, 1.64-6.19; P < .001) were detected. Multivariate analysis indicated that anticancer chemotherapy (HR, 2.47; 95% CI, 1.19-5.12; P = .015) and systemic steroids (HR, 2.40; 95% CI, 1.03-5.61; P = .044) were the independent risk factors. Of the 168 patients, 47 received SDD. According to Gray's test, SDD might have reduced the rate of recurrence but this was not statistically significant (HR, 0.46; 95% CI, 0.18-1.18; P = .11). However, in a proportional hazard modeling analysis, SDD reduced the rate of recurrence (HR, 0.36; 95% CI, 0.13-1.00; P = .050).

Conclusions

The 100-day cumulative incidence of recurrent H. cinaedi bacteremia was 18.7%. Anticancer chemotherapy and systemic steroids were independent risk factors for recurrent bacteremia. SDD is a potential strategy for reducing the recurrence.

First evidence of bacterial translocation from the intestinal tract as a route of Helicobacter cinaedi bacteremia

BACKGROUND

The route of Helicobacter cinaedi bacteremia has not yet been clarified. Although bacterial translocation from the intestinal tract into the circulation has been suggested, it has not been demonstrated thus far. The objective of this study was to investigate the port of entry of this bacterium.

MATERIAL AND METHODS

We conducted a retrospective study on patients with H. cinaedi bacteremia between March 2009 and May 2013. Records of patients in whom H. cinaedi was detected in both blood and stool cultures were extracted. H. cinaedi was identified using gyrB-targeted PCR. Pulse-field gel electrophoresis was used to investigate the consistency of the genotypes.

RESULTS

Seventy-one patients were diagnosed with H. cinaedi bacteremia during the study period. H. cinaedi was detected in both blood and stool samples of 21 patients. Pulse-field gel electrophoresis was used to investigate the consistency of the genotypes in 18 evaluable strains (from 9 patients). The pulse-field gel electrophoresis patterns of the stool- and blood-derived strains of H. cinaedi were consistent among all 9 patients. Most of the 9 patients analyzed were immunocompromised and being treated with anticancer drugs or steroids, which suggests reduced intestinal immunity.

CONCLUSIONS

This is the first study to demonstrate that bacterial translocation from the intestinal tract could represent one route of H. cinaedi bacteremia.

Epithelial Coculture and l-Lactate Promote Growth of Helicobacter cinaedi under H2-Free Aerobic Conditions

Helicobacter cinaedi is an emerging opportunistic pathogen associated with infections of diverse anatomic sites. Nevertheless, the species demonstrates fastidious axenic growth; it has been described as requiring a microaerobic atmosphere, along with a strong preference for supplemental H₂ gas. In this context, we examined the hypothesis that in vitro growth of H. cinaedi could be enhanced by coculture with human epithelial cells. When inoculated (in Ham's F12 medium) over Caco-2 monolayers, the type strain (ATCC BAA-847) gained the ability to proliferate under H₂-free aerobic conditions. Identical results were observed during coculture with several other monolayer types (LS-174T, AGS, and HeLa). Under chemically defined conditions, 40 amino acids and carboxylates were screened for their effect on the organism's atmospheric requirements. Several molecules promoted H₂-free aerobic proliferation, although it occurred most prominently with millimolar concentrations of l-lactate. The growth response of H. cinaedi to Caco-2 cells and l-lactate was confirmed with a collection of 12 human-derived clinical strains. mRNA sequencing was next performed on the type strain under various growth conditions. In addition to providing a whole-transcriptome profile of H. cinaedi, this analysis demonstrated strong constitutive expression of the l-lactate utilization locus, as well as differential transcription of terminal respiratory proteins as a function of Caco-2 coculture and l-lactate supplementation. Overall, these findings challenge traditional views of H. cinaedi as an obligate microaerophile.

IMPORTANCE

H. cinaedi is an increasingly recognized pathogen in people with compromised immune systems. Atypical among other members of its bacterial class, H. cinaedi has been associated with infections of diverse anatomic sites. Growing H. cineadi in the laboratory is quite difficult, due in large part to the need for a specialized atmosphere. The suboptimal growth of H. cinaedi is an obstacle to clinical diagnosis, and it also limits investigation into the organism's biology. The current work shows that H. cinaedi has more flexible atmospheric requirements in the presence of host cells and a common host-derived molecule. This nutritional interplay raises new questions about how the organism behaves during human infections and provides insights for how to optimize its laboratory cultivation.

Draft genome sequences of six enterohepatic helicobacter species isolated from humans and one from rhesus macaques

Draft genome sequences of seven enterohepatic Helicobacter species, H. bilis, H. canadensis, H. canis, H. cinaedi, H. winghamensis, H. pullorum, and H. macacae, are presented. These isolates were obtained from clinical patients and a nonhuman primate. Due to potential zoonotic risks, we characterized antibiotic resistance markers and Helicobacter virulence factors.

Clinical and bacteriological characteristics of Helicobacter cinaedi infection

Helicobacter cinaedi was first isolated from rectal cultures from homosexual men in 1984. In the 1980s to mid 1990s, the microorganism was mainly isolated from samples from homosexual men or immunocompromised patients; however, during the last two decades, H. cinaedi has been isolated from immunocompromised and from immunocompetent individuals worldwide. In Japan, the isolation of this microorganism was first reported in 2003. Since then, many cases have been reported in hospitals across the country. Despite many reports, the etiological properties and pathogenicity of H. cinaedi remain elusive; however, we are increasingly able to recognize some of the features and the clinical relevance of infection. In particular, a long incubation period is essential for detection in an automatic blood culture system and many of the recent isolates are resistant to both macrolides and quinolones. Furthermore, there is an association between infection and severe or chronic illnesses, such as meningitis or arteriosclerosis, in addition to mild diseases such as fever, abdominal pain, gastroenteritis, proctitis, diarrhea, erysipelas, cellulitis, arthritis, and bacteremia. In this review, we introduce the current knowledge and our latest findings relating to H. cinaedi.

Molecular epidemiologic analysis and antimicrobial resistance of Helicobacter cinaedi isolated from seven hospitals in Japan

Helicobacter cinaedi colonizes the colons of human and animals and can cause colitis, cellulitis, and sepsis in humans, with infections in immunocompromised patients being increasingly recognized. However, methods for analyzing the molecular epidemiology of H. cinaedi are not yet established. A genotyping method involving multilocus sequence typing (MLST) was developed and used to analyze 50 H. cinaedi isolates from Japanese hospitals in addition to 6 reference strains. Pulsed-field gel electrophoresis (PFGE) results were also compared with the MLST results. Based on the genomic information from strain CCUG18818, 21 housekeeping genes were selected as candidates for MLST and were observed to have high homology (96.5 to 100%) between isolates. Following a comparison of the 21 housekeeping genes from 8 H. cinaedi isolates, 7 genes were chosen for MLST, revealing 14 sequence types (STs). The isolates from 3 hospitals belonged to the same STs, but the isolates from the other 4 hospitals belonged to different STs. Isolates belonging to ST6 were analyzed by PFGE and showed similar, but not identical, patterns between isolates. Isolates belonging to ST9, ST10, and ST11, which belonged to the same clonal complex, had the same pattern. All isolates were found to contain mutations in GyrA and the 23S rRNA gene that confer ciprofloxacin and clarithromycin resistance, respectively, in H. cinaedi. These results raise concerns about the increase in H. cinaedi isolates resistant to clarithromycin and ciprofloxacin in Japan.

Helicobacter cinaedi cellulitis and bacteremia in immunocompetent hosts after orthopedic surgery

At various times after orthopedic operations (more than a few weeks, with an average of 29.9 days), 11 patients had a sudden onset of high temperature (average 38.9 degrees C) and local cellulitis at different sites on the operated sides. The wounds had completely healed, without complicated infections, when the cellulitis occurred. The clinical picture of cellulitis in all patients was atypical: diffuse salmon-pink skin color, local heat, swelling, spontaneous pain, and tenderness but no eruptions. No patient had any underlying immunocompromising conditions or had been given immunosuppressive agents. Gram-negative spiral bacteria were isolated from blood cultures and were identified as Helicobacter cinaedi on the basis of 16S rRNA gene sequencing and DNA-DNA hybridization using standard strains. By means of phylogenetic analysis, we divided these clinical isolates into two clones. The H. cinaedi strain isolated via fecal cultures from two patients without intestinal symptoms was the same clone as the blood isolate. All isolates were quite susceptible to various antibiotics, and clinical and inflammatory symptoms of bacteremia and cellulitis improved after treatment with penicillins and cephalosporins. A relatively high incidence of recurrence of the same disease was observed, however. Almost all patients responded immunologically to the infection, as evidenced by the production of serum antibody against H. cinaedi. We thus suggest that H. cinaedi should not be regarded as simply an opportunistic pathogen but that it may be a pathogen in immunocompetent hosts and may cause infections together with bacteremia and cellulitis.

Recurrent bacteremia with Helicobacter cinaedi: case report and review of the literature

Background

Helicobacter cinaedi is a rare pathogen in humans, occurring mostly in immuno-compromised patients, with a high potential for recurrence. We describe a case of a patient with lymphoma hospitalized for chemotherapy.

Case presentation

At admission, the patient presented with an indolent and non-prurigenic macular rash around her implantable venous access device. Gram staining of blood cultures revealed the presence of spiral-shaped gram-negative rods that could not be grown upon subculture. Helicobacter cinaedi was identified by PCR. No other symptoms or pathology were observed in a whole body CT scan. The implantable venous access device was removed and empiric therapy by ceftriaxone and gentamicin for 2 weeks was initiated, followed by peroral clarithromycin 2 × 500 mg/day and later by levofloxacin 2 × 500 mg/day for 7 weeks. Oncologic remission was achieved 3 months later. However, the patient was re-hospitalized 2 months later for fever, shivering, reappearance of the macular non-prurigenic rash, diarrhea, cough and asthenia. Blood cultures grew H. cinaedi. Multiple investigations could not identify the source. Empiric antibiotic therapy of ceftriaxone and doxycycline was started for 2 weeks with resolution of symptoms, followed by an oral combination of amoxicillin, metronidazole and doxycycline for 2 months; doxycycline was continued for another month. Bacteremia has not recurred for a period of 19 months.

Conclusion

Although H. cinaedi is considered to be a low virulent bacteria, its potential to cause recurrent bacteremia should not be underestimated. H. cinaedi could have an endovascular source of infection and should be treated for an adequate duration with combined antibiotherapy.

Helicobacter cinaedi-associated bacteraemia and erysipelas in an immunocompetent host: a diagnostic challenge

Helicobacter cinaedi was initially recovered from homosexual men infected with human immunodeficiency virus. Later, it was also isolated from patients with chronic alcoholism, and anecdotally from non-immunocompromized men, women, and children. We describe a case of H. cinaedi-associated bacteraemia and erysipelas in a homosexual but immunocompetent male and the diagnostic problems in identifying the causative organism.

Captive rhesus monkeys (Macaca mulatta) are commonly infected with Helicobacter cinaedi

Helicobacter cinaedi may cause proctocolitis or bacteremia in homosexual men infected with human immunodeficiency virus or occasionally in other immunocompromised hosts. There are scattered reports of H. cinaedi isolated from a variety of animal hosts, but to date only hamsters have been found to be a common natural reservoir. Microaerophillic cultures of feces from 5 of 16 asymptomatic rhesus monkeys (Macaca mulatta) (31%) were positive for a curved gram-negative rod. A polyphasic taxonomic approach was used to identify the organism as H. cinaedi. These results show that H. cinaedi frequently colonizes asymptomatic captive rhesus monkeys, which may serve as another potential reservoir for human infection.

Emergence of diverse Helicobacter species in the pathogenesis of gastric and enterohepatic diseases

Since Helicobacter pylori was first cultivated from human gastric biopsy specimens in 1982, it has become apparent that many related species can often be found colonizing the mucosal surfaces of humans and other animals. These other Helicobacter species can be broadly grouped according to whether they colonize the gastric or enterohepatic niche. Gastric Helicobacter species are widely distributed in mammalian hosts and are often nearly universally prevalent. In many cases they cause an inflammatory response resembling that seen with H. pylori in humans. Although usually not pathogenic in their natural host, these organisms serve as models of human disease. Enterohepatic Helicobacter species are an equally diverse group of organisms that have been identified in the intestinal tract and the liver of humans, other mammals, and birds. In many cases they have been linked with inflammation or malignant transformation in immunocompetent hosts and with more severe clinical disease in immunocompromised humans and animals. The purpose of this review is to describe these other Helicobacter species, characterize their role in the pathogenesis of gastrointestinal and enterohepatic disease, and discuss their implications for our understanding of H. pylori infection in humans.

Bacteremia and skin/bone infections in two patients with X-linked agammaglobulinemia caused by an unusual organism related to Flexispira/Helicobacter species

Two patients with Bruton's X-linked agammaglobulinemia are described with bacteremia and skin/bone infection due to an organism which by 16S rRNA gene sequence analysis was most closely related to "Flexispira" rappini (and thus designated a Flexispira-like organism, FLO) and more distantly related to the Helicobacter species. The organism required microaerobic conditions and, supplemental H(2) gas for growth and was reliably stained with acridine orange. In common with Helicobacter cinaedi infections, the focus of the FLO infection was in one case in the blood vessels or lymphatics of an extremity and in the other case in the skin and adjacent bone of an extremity. In both cases, prolonged IV antibiotic therapy was necessary to clear the infection. The susceptibility of XLA patients to FLO infection appears to be related to the fact that XLA is associated with severe B cell (humoral) immunodeficiency and thus these patients have difficulty with intravascular or intralymphatic infection. These findings elucidate the nature of FLO infections in humans and point the way to their detection and treatment.

Simultaneous identification of campylobacters and prediction of quinolone resistance by comparative sequence analysis

Comparative sequence analysis of a 30-bp segment in the quinolone resistance-determining region of campylobacters not only allows for the detection of base changes associated with resistance but also is a powerful tool for species identification based on silent mutations.

Helicobacter cinaedi bacteraemia: varied clinical manifestations in three homosexual males

We report 3 cases of Helicobacter cinaedi bacteraemia in different hosts representing a spectrum of clinical illness associated with this infection. The first was an AIDS patient with relapsing H. cinaedi bacteraemia despite antibiotic treatment. The second was an HIV seronegative homosexual man with end-stage renal failure, receiving haemodialysis and a previous history of chronic lymphoedema of his legs. He developed H. cinaedi bacteraemia with cellulitis of his left leg. Patient 3, an HIV seronegative homosexual man, had transient H. cinaedi bacteraemia 2 days after the completion of a course of chemotherapy for bilateral testicular carcinoma. The clinical spectrum of disease associated with H. cinaedi is broad, with few specific clinical features. Successful recovery of this fastidious organism from blood aids in the diagnosis of this unusual infection.

Genotypic and phenotypic characterization of Helicobacter cinaedi and Helicobacter fennelliae strains isolated from humans and animals

By DNA-DNA hybridization, we classified 26 human strains, 4 dog and cat strains, and 4 hamster strains putatively identified as Helicobacter cinaedi as well as 2 human strains and 2 animal strains of Helicobacter fennelliae. All but one human strain belonged to the same hybridization group as the type strain of H. cinaedi. The animal strains also appeared to belong to this hybridization group. Both human strains of H. fennelliae were shown to be H. fennelliae by DNA-DNA hybridization, but both animal strains were less than 15% related to the type strain. All strains were also characterized by plasmid profiles and ribotyping. Plasmids were found in 23% of the human strains, 100% of the hamster strains, and 33% of the dog and cat strains. Human strains were essentially identical by ribotyping, but were clearly differentiated from the hamster and dog and cat strains. Some strains may be difficult to culture on primary isolation; we found that our strains grew well on anaerobic CDC agar, brucella agar, and tryptic soy agar II. Our H. cinaedi and H. fennelliae strains differed from those previously described because some were resistant to cephalothin: some H. cinaedi strains were also resistant to nalidixic acid. All isolates were also characterized by antimicrobial susceptibility testing. We found that human strains of H. cinaedi were more resistant to clindamycin and erythromycin than were animal isolates; 19% of the human strains were resistant to ciprofloxacin. Therefore, we recommend that antimicrobial susceptibility results be obtained before initiating therapy for H. cinaedi and H. fennelliae infections.