Recurrent bacteremia caused by a "Flexispira"-like organism in a patient with X-linked (Bruton's) agammaglobulinemia

Effects of iodoacetic acid drinking water disinfection byproduct on the gut microbiota and its metabolism in rats

Iodoacetic acid (IAA) is an unregulated disinfection byproduct in drinking water and has been shown to exert cytotoxicity, genotoxicity, tumorigenicity, and reproductive and developmental toxicity. However, the effects of IAA on gut microbiota and its metabolism are still unknown, especially the association between gut microbiota and the metabolism and toxicity of IAA. In this study, female and male Sprague-Dawley rats were exposed to IAA at 0 and 16 mg/kg bw/day daily for 8 weeks by oral gavage. Results of 16S rRNA gene sequencing showed that IAA could alter the diversity, relative abundance and function of gut microbiota in female and male rats. IAA also increased the abundance of genes related to steroid hormone biosynthesis in the gut microbiota of male rats. Moreover, metabolomics profiling revealed that IAA could significantly disturb 6 and 13 metabolites in the feces of female and male rats, respectively. In female rats, the level of androstanediol increased in the IAA treatment group. These results were consistent with our previous findings, where IAA was identified as an androgen disruptor. Additionally, the perturbed gut microbiota and altered metabolites were correlated with each other. The results of this study indicated that IAA could disturb gut microbiota and its metabolism. These changes in gut microbiota and its metabolism were associated with the reproductive and developmental toxicity of IAA.

Infections With Enterohepatic Non-H. pylori Helicobacter Species in X-Linked Agammaglobulinemia: Clinical Cases and Review of the Literature

The genus Helicobacter is classified into two main groups according to its habitat: gastric and enterohepatic. Patients with X-linked agammaglobulinemia (XLA) appear to be associated with invasive infection with enterohepatic non-Helicobacter pylori species (NHPH), mainly H. cinaedi and H. bilis. Such infections are difficult to control and have a high potential for recurrence. The spectrum of illnesses caused by these species includes recurrent fever, bacteremia, arthritis, osteomyelitis, cellulitis, abdominal abscesses, and pyoderma gangrenosum-like ulcer. The presence of these Helicobacters is particularly difficult to diagnose and eradicate, as they are very fastidious bacteria and present resistance to several types of antibiotics. We report two clinical cases of XLA patients infected with H. bilis. These infections were chronic in these patients and could not be eradicated in one of them. We also review the cases of enterohepatic non-Helicobacter pylori species (NHPH) in patients with this inborn error of immunity.

Bacteremia and Skin Infections in Four Patients Caused by Helicobacter-Like Organisms

Background

Enterohepatic Helicobacter-like organisms (HLO) have been recognized as causes of human infection since 1984, primarily as a cause of bacteremia and cellulitis in immunocompromised individuals, but the spectrum of illness due to HLO has expanded based on numerous reports from Japan.

Methods

We report 4 epidemiologically unrelated immunocompetent patients with HLO bacteremia diagnosed within a 2-year period. Three patients had cellulitis and 1 patient had unexplained fever. 16S ribosomal deoxyribonucleic acid (rDNA) sequence analysis of 2 isolates suggested that they were Helicobacter cinaedi, and whole-genome sequencing showed that they differed only slightly from reference strains.

Conclusions

We believe that this syndrome is more common than reported, but it is easily overlooked because the skin lesions resemble streptococcal cellulitis and respond very rapidly to β-lactam antibiotics, and the organism is difficult to isolate from the blood. All HLO in our series were isolated from blood using the ESP system and were not detected in 2 other widely used commercial blood culture systems.

Helicobacter cinaedi bacteremia resulting from antimicrobial resistance acquired during treatment for X-linked agammaglobulinemia

This is the first report of penicillin/cephalosporin-resistant Helicobacter cinaedi arising from prolonged treatment. H. cinaedi, common among immunocompromised patients, caused recurrent bacteremia and cellulitis in a 19-year-old Japanese man with X-linked agammaglobulinemia. The minimal inhibitory concentration of these drugs was raised, which subsequently resulted in clinical failure. Prolonged suboptimal treatment may cause bacterial resistance to β-lactam antibiotics in H. cinaedi. It is possible that this resistance may have contributed to the treatment failure.

A novel treatment in X-linked agammaglobulinaemia - hyperbaric oxygen therapy in refractory chronic wounds

Chronic wounds are a rare complication of X-linked agammaglobulinaemia (XLA). Fastidious organisms such as helicobacter bills have been reported in XLA with chronic wounds but sterile chronic wounds also occur. Hyperbaric Oxygen Therapy has been used in chronic wounds but has not previously been reported in primary antibody deficiencies. We present a case of a chronic wound in a patient with XLA refractory to antimicrobial therapy that made a remarkable recovery following Hyperbaric Oxygen Therapy.

Bacteremia caused by a novel helicobacter species in a 28-year-old man with X-linked agammaglobulinemia

We report on a case of bacteremia caused by a previously unknown urease-negative Helicobacter strain, IMMIB HP-28/08, isolated from blood cultures of a 28-year-old man with X-linked agammaglobulinemia. The identification of the isolate was based on 16S rRNA gene sequencing. In the phylogenetic tree, the isolate fell into a cluster which included Helicobacter canadensis, Helicobacter equorum, and Helicobacter pullorum. This is the first report of bacteremia caused by this fastidious organism. Further investigations are necessary to determine the potential role of this species as a pathogen of bloodstream infections.

Experimental Helicobacter marmotae infection in A/J mice causes enterohepatic disease

Helicobacter marmotae has been identified in the inflamed livers of Eastern woodchucks (Marmota monax) infected with woodchuck hepatitis virus (WHV), as well as from the livers of WHV-negative woodchucks. Because the majority of WHV-positive woodchucks with hepatic tumours were culture or PCR positive for this helicobacter, and WHV-negative woodchucks with H. marmotae had hepatitis, the bacterium may have a role in tumour promotion related to chronic inflammation. In this study, the type strain of H. marmotae was inoculated intraperitoneally into 48 male and female A/J mice, a strain noted to be susceptible to Helicobacter hepaticus-induced liver tumours. Sixteen mice served as mock-dosed controls. At 6, 12 and 18 months post-inoculation (p.i.), there were statistically significant (P<0.05) differences in mean inflammation scores for the caecum and proximal colon between experimentally infected and control mice. Differences in hepatic inflammation were significant (P<0.05) at 6 and 12 months p.i. between the two groups but not at the 18 month time point. Two infected male mice had livers with severe hepatitis, and the liver samples were culture positive for H. marmotae. Serum IgG levels in the mice dosed with H. marmotae were elevated for the duration of the study. These results demonstrate that the woodchuck helicobacter can successfully colonize mice and cause enterohepatic disease. In the future, a mouse-adapted strain of H. marmotae could be selected to maximize colonization and lesion development. Such a woodchuck helicobacter-infected mouse model could be used to dissect potential mechanisms of microbial co-carcinogenesis involved in tumour development in woodchucks with WHV and in humans with hepatitis B virus.

Pyoderma gangrenosum-like ulcer in a patient with X-linked agammaglobulinemia: identification of Helicobacter bilis by mass spectrometry analysis

BACKGROUND

Pyoderma gangrenosum-like ulcers and cellulitis of the lower extremities associated with recurrent fevers in patients with X-linked (Bruton) agammaglobulinemia have been reported to be caused by Helicobacter bilis (formerly classified as Flexispira rappini and then Helicobacter strain flexispira taxon 8). Consistent themes in these reports are the difficulty in recovering this organism in blood and wound cultures and in maintaining isolates in vitro. We confirmed the presence of this organism in a patient's culture by using a novel application of gene amplification polymerase chain reaction and electrospray ionization time-of-flight mass spectrometry.

OBSERVATION

An adolescent boy with X-linked agammaglobulinemia presented with indurated plaques and a chronic leg ulcer whose origin was strongly suspected to be an H bilis organism. Histologic analysis demonstrated positive Warthin-Starry staining of curvilinear rods, which grew in culture but failed to grow when subcultured. They could not be identified by conventional techniques. A combination of gene amplification by polymerase chain reaction and electrospray ionization time-of-flight mass spectrometry confirmed the identity of this organism.

CONCLUSIONS

This novel technology was useful in the identification of a difficult-to-grow Helicobacter organism, the cause of pyoderma gangrenosum-like leg ulcers in patients with X-linked agammaglobulinemia. Correct identification of this organism as the cause of pyoderma gangrenosum-like ulcers in patients with X-linked agammaglobulinemia is of great importance for the early initiation of appropriate and curative antibiotic therapy.

Chronic hepatitis, hepatic dysplasia, fibrosis, and biliary hyperplasia in hamsters naturally infected with a novel Helicobacter classified in the H. bilis cluster

We recently described helicobacter-associated progressive, proliferative, and dysplastic typhlocolitis in aging (18- to 24-month-old) Syrian hamsters. Other pathogens associated with typhlocolitis in hamsters, Clostridium difficile, Lawsonia intracellularis, and Giardia spp., were not indentified. The presence of Helicobacter genus-specific DNA was noted by PCR in cecal and paraffin-embedded liver samples from aged hamsters by the use of Helicobacter-specific PCR primers. By 16S rRNA analysis, the Helicobacter sp. isolated from the liver tissue was identical to the cecal isolates from hamsters. The six hamster 16S rRNA sequences form a genotypic cluster most closely related to Helicobacter sp. Flexispira taxon 8, part of the Helicobacter bilis/H. cinaedi group. Livers from aged helicobacter-infected hamsters showed various stages of predominantly portocentric and, to a lesser extent, perivenular fibrosis. Within nodules, there was cellular atypia consistent with nodular dysplasia. The livers also exhibited a range of chronic active portal/interface and lobular inflammation, with significant portal hepatitis being present. The inflammation was composed of a mixture of lymphocytes, neutrophils, and macrophages, indicative of its chronic-active nature in these aged hamsters infected with Helicobacter spp. The isolation of novel Helicobacter spp., their identification by PCR from the diseased livers of aged hamsters, and their taxonomic classification as belonging to the Helicobacter bilis cluster strengthen the argument that H. bilis and closely related Helicobacter spp. play an etiological role in hepatobiliary disease in both animals and humans.

Multicenter study to evaluate bloodstream infection by Helicobacter cinaedi in Japan

Helicobacter cinaedi has being recognized as an important human pathogen which causes bloodstream infections. Although the first case of bacteremia with this pathogen in Japan was reported in 2003, the true prevalence of H. cinaedi as a pathogen of bloodstream infections in this country is not yet known. Therefore, the aim of our study was to assess the incidence of bacteremia with H. cinaedi in Japan. We conducted a prospective, multicenter analysis in 13 hospitals during 6 months in Tokyo, Japan. Among positive blood cultures from 1 October 2003 to 31 March 2004, isolates suspected of being Helicobacter species were studied for further microbial identification. Identification of the organisms was based on their biochemical traits and the results of molecular analysis of their 16S rRNA gene sequences. A total of 16,743 blood culture samples were obtained during the study period, and 2,718 samples (17.7%) yielded positive culture results for coagulase-negative staphylococci. Among nine isolates suspected to be Helicobacter species, six isolates were finally identified as H. cinaedi. The positivity rate for H. cinaedi in blood culture was 0.06% of total blood samples and 0.22% of blood samples with any positive culture results. All patients with bacteremia with H. cinaedi were found to have no human immunodeficiency virus (HIV) infection, but many of them had complications with either malignancy, renal failure, or a history of surgical operation. Therefore, our results suggest that bacteremia with H. cinaedi is rare but can occur in compromised hosts other than those with HIV infection in Japan.

Extension of the species Helicobacter bilis to include the reference strains of Helicobacter sp. flexispira taxa 2, 3 and 8 and Finnish canine and feline flexispira strains

The evolution and taxonomy of enterohepatic Helicobacter species with flexispira morphology were studied by a polyphasic approach including phenotypic characterization, analysis of 16S rRNA and ureB gene sequences and dot-blot DNA-DNA hybridization of whole genomic DNA. In addition, available phylogenetic data on the HSP60 gene were used in the analysis. The study included 14 Finnish canine and feline flexispira strains, the reference strains of Helicobacter sp. flexispira taxa 2, 3 and 8 and Helicobacter bilis ATCC 51630(T). Phenotypically, all canine and feline strains were similar to H. bilis. Analysis of 16S rRNA gene sequences of these strains revealed a similarity of 97-99.5 %. Similarity of ureB nucleotide and amino acid sequences within the studied flexispira group was 97-100 % and 99-100 %, respectively, revealing close relatedness. ureB sequences of Helicobacter hepaticus had only 64-66 % similarity to the flexispira group. The similarity to Helicobacter trogontum was 81.5-82.1 %. High levels of DNA-DNA hybridization between the strains were found in dot-blot tests. Polyphasic analysis of the phenotypic and genotypic characteristics of the Finnish flexispira strains and the reference strains of taxa 2, 3 and 8 showed that they differed from other Helicobacter species and are members of the previously described species H. bilis. In addition, canine strain F56 differed in all phylogenetic analyses from the H. bilis group and probably represents a novel Helicobacter species.

Genotypic identification of erythromycin-resistant campylobacter isolates as helicobacter species and analysis of resistance mechanism

The correct identification of Campylobacter species remains cumbersome, especially when conventional biochemical tests and antimicrobial susceptibility patterns are used for a phenotypical identification. Correct identification is important for epidemiological purposes and for studying changes in antimicrobial resistance patterns. Six erythromycin-resistant campylobacter strains were investigated by 16S ribosomal DNA (rDNA) sequencing, 23S rDNA sequencing, and restriction fragment length polymorphism analysis of a putative heme-copper oxidase domain described as being specific for thermophilic Campylobacter species. Three erythromycin-resistant isolates from feces of human immunodeficiency virus (HIV)-seropositive patients with diarrhea and one blood isolate of from HIV-seropositive patient with cellulitis were identified by 16S rDNA analysis as Helicobacter cinaedi, whereas 23S rDNA sequencing suggested Wolinella succinogenes. The 16S rDNA sequence data of fecal isolates of two patients with travelers diarrhea revealed Helicobacter pullorum and were also in contrast with 23S rDNA sequencing. Of 4 H. cinaedi isolates, 1 contained the putative heme-copper oxidase gene thought to be specific for thermophilic species. The six erythromycin-resistant Helicobacter species had a similar point mutation A2143G in 23S rDNA resembling the macrolides resistance in Helicobacter pylori. We conclude that 16S rDNA sequencing should be preferred to 23S rDNA analysis and that macrolide-resistant campylobacter strains should be investigated by this approach for a correct identification.

Helicobacter sp. flexispira 16S rDNA taxa 1, 4 and 5 and Finnish porcine Helicobacter isolates are members of the species Helicobacter trogontum (taxon 6)

The term 'flexispira' refers to micro-organisms with a particular morphology: fusiform-shaped with helical periplasmic fibrils and bipolar tufts of sheathed flagella. Two flexispira taxa have been formally named, Helicobacter bilis and Helicobacter trogontum, a third named species is Helicobacter aurati and eight additional 16S rRNA sequence-based flexispira taxa have been described by Dewhirst et al. (Int J Syst Evol Microbiol 50, 1781-1787, 2000) and given the provisional designation Helicobacter sp. flexispira taxa 1-5, 7, 8 and 10. In the present study, seven gastric or intestinal flexispira isolates from seven Finnish pigs originating from different farms were characterized. Morphologically, all these porcine isolates had typical flexispira morphology. Analysis of the 16S rDNA sequences of five isolates showed that they were most closely related to the sequences of flexispira taxa 4 and 5 and H. trogontum (taxon 6), but less closely related to taxa 1-3 and 8, H. bilis and H. aurati. Phenotypic characterization, analysis of RFLPs of 16S and 23S rDNAs and SDS-PAGE profiles revealed that all of the porcine isolates, reference strains of flexispira taxa 1, 4 and 5 and the type strain of H. trogontum (ATCC 700114T) had highly related characteristics that differed from those of the reference strains of taxa 2, 3 and 8 and H. bilis. Furthermore, a high DNA-DNA binding rate was found, in dot-blot hybridization studies, between the Finnish porcine strains, taxa 1, 4 and 5 reference strains and H. trogontum ATCC 700114T. In conclusion, polyphasic characterization of novel porcine flexispira isolates and previously described taxa 1, 4 and 5 reference strains showed that they all belong to a validly described species, H. trogontum, and that the taxonomy of known flexispiras is less complicated than proposed on the basis of 16S rDNA sequence analysis.

Unique case of Helicobacter sp. osteomyelitis in an immunocompetent child diagnosed by broad-range 16S PCR

We report the first case of Helicobacter sp. osteomyelitis in an immunocompetent child. The infection was diagnosed by broad-range 16S PCR followed by sequencing of the resulting amplicon. All other microbiological investigations proved negative. This case highlights the importance of molecular methods in the diagnosis of unsuspected etiological agents and the potential role of Helicobacter sp. in human infection.

The non-H pylori helicobacters: their expanding role in gastrointestinal and systemic diseases

The number of species in the genus Helicobacter has rapidly expanded over the past decade. The genus now includes at least 24 formally named species as well as numerous other helicobacters awaiting formal naming. This review highlights the expanding role that other helicobacters, although not as well known as H pylori, play in gastrointestinal and systemic disease in humans.

Recurrent bacteremia and multifocal lower limb cellulitis due to Helicobacter-like organisms in a patient with X-linked hypogammaglobulinemia

We describe a 27-year-old man with X-linked (Bruton's) hypogammaglobulinemia who presented during a 10-month period with recurrent fevers and multifocal lower-limb cellulitis associated with bacteremia due to Helicobacter-like organisms ("Flexispira rappini" and Helicobacter canis). Susceptible individuals may acquire infection of this type as a result of exposure to young dogs.

"Helicobacter rappini" isolates from 2 homosexual men

We report 2 cases of bacteremia due to "Helicobacter rappini" in 2 young, homosexual men, including the first report of H. rappini in a human immunodeficiency virus-positive patient. Blood cultures showed a spiral, fusiform, gram-negative bacterium with bipolar sheathed flagella.

Helicobacter sp. flexispira bacteremia in an immunocompetent young adult

A young immunocompetent patient was admitted for a febrile illness with malaise, arthralgias, painful leg swelling, and polyserositis. Shortly prior to becoming ill, the patient had traveled to the Northern African desert. The symptoms disappeared during treatment with antibiotics (doxycycline and ceftriaxone) but recurred twice after stopping therapy. A motile gram-negative fusiform rod was isolated from a blood culture taken on the first admission. Analysis of the 16S rRNA gene of the blood culture isolate revealed close similarity with Helicobacter sp. flexispira taxon 8 (99.9% identity), a species that was previously reported as "Flexispira rappini." This is the first reported case of a recurrent Helicobacter sp. flexispira bacteremia in an adult, immunocompetent patient.

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.

Identification of enterohepatic Helicobacter species by restriction fragment-length polymorphism analysis of the 16S rRNA gene

BACKGROUND

Restriction fragment-length polymorphism (RFLP) analysis of a 1,200-bp polymerase chain reaction-amplified DNA fragment of gene coding for 16S rRNA was used to generate restriction profiles of 11 enterohepatic Helicobacter spp. isolated from various animals and humans.

METHODS

The amplicon from each Helicobacter sp. was digested with four restriction endonucleases: Alu I, Hinf I, Hha I, and Dde I. Alu I digestion produced five patterns that were useful for initial differentiation.

RESULTS

Most Helicobacter spp. isolated from rodents had the same RFLP profiles by Alu I digestion (except H. rodentium and H. cholecystus), but they had different RFLP profiles by Hha I digestion. Only H. bilis and "H. rappini" mouse isolates could not be readily distinguished by the polymerase chain reaction-RFLP method. However, these two species can be distinguished using H. bilis specific primers. Some of the Helicobacter spp. have an intervening sequence in their 16S rRNA gene, which changes the RFLP patterns; in these cases, sequencing is the preferred method to make an appropriate diagnosis.

CONCLUSIONS

The RFLP method used in this study was straightforward and rapid and should prove useful as an adjunct for identification and classification of multiple enterohepatic Helicobacter spp.

Unusual infections and novel therapy in the immunocompromised host

New methods of identification have led to an ever-increasing number of unusual pathogens causing infection in the immunocompromised host. Reports of antimicrobial-resistant organisms in this group of patients are also increasing, with the result that new treatments must be sought urgently. New agents and new strategies for the development of antimicrobial agents are critical for future progress in the treatment of resistant organisms.

Identification of a unique Helicobacter species by 16S rRNA gene analysis in an abdominal abscess from a patient with X-linked hypogammaglobulinemia

A unique Helicobacter species, MZ640285, was isolated from a patient with X-linked hypogammaglobulinemia suffering from recurrent abdominal abscesses and was identified by 16S rRNA gene sequence analysis. In the phylogenetic tree, the isolate fell into a cluster which included Flexispira rappini, Helicobacter bilis, and Helicobacter sp. strain Mainz. Helicobacters are being increasingly recognized as pathogens in immunocompromised hosts. These fastidious bacteria are not easily cultured in the routine diagnostic laboratory, and this is the first report of their identification by 16S rRNA gene sequencing performed directly from a clinical specimen.