Triple-drug combination therapy versus six-month proton pump inhibitor monotherapy in non-Helicobacter pylori Helicobacter eradication, and hyperacid environment preference of Helicobacter suis: a clinical study.

BACKGROUND: At present, eradication regimens for non-Helicobacter pylori Helicobacter (NHPH) have not been established yet. We investigated effectiveness of the standard triple-drug combination therapy for Helicobacter pylori eradication and of a proton pump inhibitor (PPI) monotherapy in eradication of NHPH. METHODS: Subjects were the patients who were diagnosed with NHPH-infected gastritis based on microscopic findings, helical-shaped organisms obviously larger than Helicobacter pylori, in the gastric mucosal specimens using Giemsa staining at Kenwakai Hospital between November 2010 and September 2021, whose NHPH species were identified by polymerase chain reaction (PCR) analysis of urease genes in endoscopically-biopsied samples, and who consented to NHPH eradication with either the triple-drug combination therapy for one week or a PPI monotherapy for six months. Six months after the completion of eradication, its result was determined with esophagogastroduodenoscopy, microscopic examination, and PCR analysis. In cases of unsuccessful eradication, a second eradication with the other therapy was suggested to the patient. RESULTS: PCR analysis detected NHPH in 38 patients: 36 as Helicobacter suis and two as Helicobacter heilmannii/Helicobacter ailurogastricus. Fourteen Helicobacter suis-infected and one Helicobacter heilmannii/Helicobacter ailurogastricus-infected patients requested eradication therapy. The triple-drug combination therapy succeeded in four of five patients, while the PPI monotherapy succeeded in five of 10 patients. Three of five patients who had been unsuccessful with the latter therapy requested the triple-drug combination therapy as the second eradication and all three were successful. In total, the triple-drug combination therapy succeeded in seven out of eight (87.5%) attempted cases, while the PPI monotherapy in five out of 10 (50%) attempted cases. CONCLUSIONS: In NHPH eradication, the triple-drug combination therapy was considered to be effective to some extent and to become the first-line therapy. While, although less successful, PPI monotherapy appeared to be a potentially promising option particularly for patients with allergy or resistance to antibiotics. Effectiveness of PPI monotherapy may be attributed to hyperacid environment preference of Helicobacter suis and PPI's acid-suppressive effect. Additionally, male predominance in NHPH-infected gastritis patients may be explained by gender difference in gastric acid secretory capacity. However, further evidence needs to be accumulated. STUDY REGISTRATION: This study was approved by the Research Ethics Committee of Kenwakai Hospital (No. 2,017,024).

Isolation and characterization of Helicobacter suis from human stomach.

Helicobacter suis, a bacterial species naturally hosted by pigs, can colonize the human stomach in the context of gastric diseases such as gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Because H. suis has been successfully isolated from pigs, but not from humans, evidence linking human H. suis infection to gastric diseases has remained incomplete. In this study, we successfully in vitro cultured H. suis directly from human stomachs. Unlike Helicobacter pylori, the viability of H. suis decreases significantly on neutral pH; therefore, we achieved this using a low-pH medium for transport of gastric biopsies. Ultimately, we isolated H. suis from three patients with gastric diseases, including gastric MALT lymphoma. Successful eradication of H. suis yielded significant improvements in endoscopic and histopathological findings. Oral infection of mice with H. suis clinical isolates elicited gastric and systemic inflammatory responses; in addition, progression of gastric mucosal metaplasia was observed 4 mo postinfection. Because H. suis could be isolated from the stomachs of infected mice, our findings satisfied Koch's postulates. Although further prospective clinical studies are needed, H. suis, like H. pylori, is likely a gastric pathogen in humans. Furthermore, comparative genomic analysis of H. suis using complete genomes of clinical isolates revealed that the genome of each H. suis isolate contained highly plastic genomic regions encoding putative strain-specific virulence factors, including type IV secretion system-associated genes, and that H. suis isolates from humans and pigs were genetically very similar, suggesting possible pig-to-human transmission.

Characterization of the non-glandular gastric region microbiota in Helicobacter suis-infected versus non-infected pigs identifies a potential role for Fusobacterium gastrosuis in gastric ulceration.

Helicobacter suis has been associated with development of gastric ulcers in the non-glandular part of the porcine stomach, possibly by affecting gastric acid secretion and altering the gastric microbiota. Fusobacterium gastrosuis is highly abundant in the gastric microbiota of H. suis-infected pigs and it was hypothesized that this micro-organism could play a role in the development of gastric ulceration. The aim of this study was to obtain further insights in the influence of a naturally acquired H. suis infection on the microbiota of the non-glandular part of the porcine stomach and in the pathogenic potential of F. gastrosuis. Infection with H. suis influenced the relative abundance of several taxa at phylum, family, genus and species level. H. suis-infected pigs showed a significantly higher colonization rate of F. gastrosuis in the non-glandular gastric region compared to non-infected pigs. In vitro, viable F. gastrosuis strains as well as their lysate induced death of both gastric and oesophageal epithelial cell lines. These gastric cell death inducing bacterial components were heat-labile. Genomic analysis revealed that genes are present in the F. gastrosuis genome with sequence similarity to genes described in other Fusobacterium spp. that encode factors involved in adhesion, invasion and induction of cell death as well as in immune evasion. We hypothesize that, in a gastric environment altered by H. suis, colonization and invasion of the non-glandular porcine stomach region and production of epithelial cell death inducing metabolites by F. gastrosuis, play a role in gastric ulceration.

A novel isolation protocol and probe-based RT-PCR for diagnosis of gastric infections with the zoonotic pathogen Helicobacter suis.

BACKGROUND: Helicobacter suis is a very fastidious microorganism associated with gastritis, gastric ulcers, and mucosa-associated lymphoid tissue lymphoma in humans. In vitro isolation of this agent from human patients has so far been unsuccessful. MATERIALS AND METHODS: A probe-based real-time PCR (RT-PCR) for the rapid detection of H. suis in gastric biopsies was developed. Secondly, a mouse-passage-based protocol was optimized for isolation of low numbers of viable H. suis bacteria. Mice were inoculated with different numbers of viable H. suis (102 -108 ) and kept for 4 weeks to allow multiplication of this pathogen. RESULTS: The probe-based real-time PCR (RT-PCR) exhibited a high degree of diagnostic specificity and analytical sensitivity, high linear correlations (r2 between 0.995 and 0.999), and high amplification efficiencies (>90%) for H. suis. No cross-reactivity was detected with human, porcine, non-human primate, and murine DNA nor with DNA from other bacteria including Helicobacter spp. and Campylobacter spp. H. suis was successfully re-isolated from the stomach of mice inoculated with at least 104 viable H. suis, using a biphasic medium (pH 5), consisting of Brucella agar with Brucella broth on top, both supplemented with vitox supplement, Campylobacter-selective supplement, amphotericin (5 µg/mL), HCl (0.05%), fetal bovine serum (20%), and linezolid (5 µg/mL). Linezolid was necessary to inhibit proliferation of contaminants, including lactobacilli. CONCLUSION: The methods described above can be implemented for detection or isolation of H. suis from human gastric biopsies.

Comparative virulence of in vitro-cultured primate- and pig-associated Helicobacter suis strains in a BALB/c mouse and a Mongolian gerbil model.

BACKGROUND: Helicobacter suis (H. suis) is the most prevalent gastric non-H. pylori Helicobacter species in humans. This bacterium mainly colonizes the stomach of pigs, but it has also been detected in the stomach of nonhuman primates. The aim of this study was to obtain better insights into potential differences between pig- and primate-associated H. suis strains in virulence and pathogenesis. MATERIALS AND METHODS: In vitro-isolated H. suis strains obtained from pigs, cynomolgus monkeys (Macaca fascicularis), and rhesus monkeys (Macaca mulatta) were used for intragastric inoculation of BALB/c mice and Mongolian gerbils. Nine weeks and six months later, samples of the stomach of inoculated and control animals were taken for PCR analysis and histopathological examination. RESULTS: The cynomolgus monkey-associated H. suis strain only colonized the stomach of mice, but not of Mongolian gerbils. All other H. suis strains colonized the stomach in both rodent models. In all colonized animals, severe gastric inflammation was induced. Gastric lymphoid follicles and destruction of the antral epithelium were observed in infected gerbils, but not in mice. Infection with both pig- and primate-associated H. suis strains evoked a similar marked Th17 response in mice and gerbils, accompanied by increased CXCL-13 expression levels. CONCLUSIONS: Apart from the cynomolgus monkey-associated strain which was unable of colonizing the stomach of Mongolian gerbils, no substantial differences in virulence were found in rodent models between in vitro-cultured pig-associated, cynomolgus monkey-associated and rhesus monkey-associated H. suis strains. The experimental host determines the outcome of the immune response against H. suis infection, rather than the original host.

Purification of Helicobacter suis Strains From Biphasic Cultures by Single Colony Isolation: Influence on Strain Characteristics.

BACKGROUND: Helicobacter (H.) suis causes gastritis and decreased weight gain in pigs. It is also the most prevalent non-Helicobacter pylori Helicobacter species in humans with gastric disease. H. suis is extremely fastidious, and so far, biphasic culture conditions were essential for isolation and culture, making it impossible to obtain single colonies. Hence, cultures obtained from an individual animal may contain multiple H. suis strains, which is undesirable for experiments aiming for instance at investigating H. suis strain differences. MATERIALS AND METHODS: Pure cultures of H. suis were established by growing bacteria as colonies on 1% brucella agar plates, followed by purification and enrichment by biphasic subculture. Characteristics of these single colony-derived strains were compared with those of their parent strains using multilocus sequence typing (MLST) and by studying bacterium-host interactions using a gastric epithelial cell line and Mongolian gerbil model. RESULTS: The purification/enrichment procedure required a nonstop culture of several weeks. For 4 of 17 H. suis strains, MLST revealed differences between parental and single colony-derived strains. For three of four single colony-derived strains tested, the cell death-inducing capacity was higher than for the parental strain. One single colony-derived strain lost its capacity to colonize Mongolian gerbils. For the four other strains tested, colonization capacity and histopathologic changes were similar to what has been described when using strains with only a history of limited biphasic culture. CONCLUSIONS: A method was developed to obtain single colony-derived H. suis strains, but this procedure may affect the bacterial genotype and phenotype.

Prevalence of Coinfection with Gastric Non-Helicobacter pylori Helicobacter (NHPH) Species in Helicobacter pylori-infected Patients Suffering from Gastric Disease in Beijing, China.

BACKGROUND: The Helicobacter heilmannii sensu lato (H. heilmannii s.l.) group consists of long, spiral-shaped bacteria naturally colonizing the stomach of animals. Moreover, bacteria belonging to this group have been observed in 0.2-6% of human gastric biopsy specimens, and associations have been made with the development of chronic gastritis, peptic ulceration, and gastric MALT lymphoma in humans. MATERIALS AND METHODS: To gain insight into the prevalence of H. heilmannii s.l. infections in patients suffering from gastric disease in China, H. heilmannii s.l. species-specific PCRs were performed on DNA extracts from rapid urease test (RUT)-positive gastric biopsies from 1517 patients followed by nucleotide sequencing. At the same time, Helicobacter pylori cultivation and specific PCR was performed to assess H. pylori infection in these patients. RESULTS: In total, H. heilmannii s.l. infection was detected in 11.87% (178/1499) of H. pylori-positive patients. The prevalence of H. suis, H. felis, H. bizzozeronii, H. heilmannii sensu stricto (s.s.), and H. salomonis in the patients was 6.94%, 2.20%, 0.13%, 0.07%, and 2.54%, respectively. Results revealed that all patients with H. heilmannii s.l. infection were co-infected with H. pylori, and some patients were co-infected with more than two different Helicobacter species. CONCLUSIONS: Helicobacter heilmannii s.l. infections are fairly common in Chinese patients. This should be kept in mind when diagnosing the cause of gastric pathologies in patients. Helicobacter suis was shown to be by far the most prevalent H. heilmannii s.l.species.

Development of new PCR primers by comparative genomics for the detection of Helicobacter suis in gastric biopsy specimens.

BACKGROUND: Although the infection rate of Helicobacter suis is significantly lower than that of Helicobacter pylori, the H. suis infection is associated with a high rate of gastric mucosa-associated lymphoid tissue (MALT) lymphoma. In addition, in vitro cultivation of H. suis remains difficult, and some H. suis-infected patients show negative results on the urea breath test (UBT). MATERIALS AND METHODS: Female C57BL/6J mice were orally inoculated with mouse gastric mucosal homogenates containing H. suis strains TKY or SNTW101 isolated from a cynomolgus monkey or a patient suffering from nodular gastritis, respectively. The high-purity chromosomal DNA samples of H. suis strains TKY and SNTW101 were prepared from the infected mouse gastric mucosa. The SOLiD sequencing of two H. suis genomes enabled comparative genomics of 20 Helicobacter and 11 Campylobacter strains for the identification of the H. suis-specific nucleotide sequences. RESULTS: Oral inoculation with mouse gastric mucosal homogenates containing H. suis strains TKY and SNTW101 induced gastric MALT lymphoma and the formation of gastric lymphoid follicles, respectively, in C57BL/6J mice. Two conserved nucleotide sequences among six H. suis strains were identified and were used to design diagnostic PCR primers for the detection of H. suis. CONCLUSIONS: There was a strong association between the H. suis infection and gastric diseases in the C57BL/6 mouse model. PCR diagnosis using an H. suis-specific primer pair is a valuable method for detecting H. suis in gastric biopsy specimens.

The prevalence of porcine gastric ulcer and Helicobacter suis in Taiwan.

Gastric ulcer is a common disease affecting pigs worldwide, with a prevalence reported as high as 93%. The cause of porcine gastric ulcer is multifactorial, with Helicobacter suis (H. suis) being considered as the primary pathogenic factor. To date, prevalence of H. suis resulting in porcine gastric ulcer in Taiwan has not been investigated. In this study, we collected 360 pig stomachs from the slaughterhouses. In addition, stomach tissues from the 88 diseased pigs submitted for necropsy were divided into symptomatic and asymptomatic groups. Gastric lesions were scored, and polymerase chain reaction was used to determine the occurrence of gastric ulcer and the prevalence of H. suis. The positive rate of H. suis in the samples from slaughtered pigs was 49.7%, and both infection of H. suis and the presence of gastric lesions were prone to occur in autumn. The positive rates of H. suis infection in the symptomatic and asymptomatic groups were 59.1% and 31.8%, respectively. Moreover, the proportion of the samples with gastroesophageal ulcer in the symptomatic group was 68.2%, predominantly observed in growing pigs. The incidence of the samples from the slaughterhouses with gastroesophageal erosion to ulceration revealed a significant difference between H. suis -infected and H. suis -uninfected pigs; however, there is no significant difference in the samples of diseased pigs. In conclusion, H. suis infection was associated with gastric ulcer in slaughtered pigs, but it was not the primary cause of gastroesophageal ulcer in diseased pigs with clinical symptoms.

Multilocus sequence typing of the porcine and human gastric pathogen Helicobacter suis.

Helicobacter suis is a Gram-negative bacterium colonizing the majority of pigs, in which it causes gastritis and decreased daily weight gain. H. suis is also the most prevalent gastric non-Helicobacter pylori Helicobacter species in humans, capable of causing gastric disorders. To gain insight into the genetic diversity of porcine and human H. suis strains, a multilocus sequence typing (MLST) method was developed. In a preliminary study, 7 housekeeping genes (atpA, efp, mutY, ppa, trpC, ureI, and yphC) of 10 H. suis isolates cultured in vitro were investigated as MLST candidates. All genes, except the ureI gene, which was replaced by part of the ureAB gene cluster of H. suis, displayed several variable nucleotide sites. Subsequently, internal gene fragments, ranging from 379 to 732 bp and comprising several variable nucleotide sites, were selected. For validation of the developed MLST technique, gastric tissue from 17 H. suis-positive pigs from 4 different herds and from 1 H. suis-infected human patient was used for direct, culture-independent strain typing of H. suis. In addition to the 10 unique sequence types (STs) among the 10 isolates grown in vitro, 15 additional STs could be assigned. Individual animals were colonized by only 1 H. suis strain, whereas multiple H. suis strains were present in all herds tested, revealing that H. suis is a genetically diverse bacterial species. The human H. suis strain showed a very close relationship to porcine strains. In conclusion, the developed MLST scheme may prove useful for direct, culture-independent typing of porcine and human H. suis strains.

Case report: Helicobacter suis infection in a pig veterinarian.

This study describes a non-Helicobacter (H.) pylori Helicobacter (NHPH) infection in a pig veterinarian. The patient suffered from reflux esophagitis and general dyspeptic symptoms and was referred to the hospital for upper gastrointestinal endoscopy. Histologic examination of corpus and antrum biopsies revealed a chronic gastritis. Large spiral-shaped non-H. pylori helicobacters could be visualized and were identified as H. suis by PCR. The patient was treated with a triple therapy, consisting of amoxicillin, clarithromycin, and pantoprazole for 10 days. Successful eradication was confirmed after a follow-up gastrointestinal endoscopy and PCR 10 weeks after treatment. A mild chronic gastritis was, however, still observed at this point in time. This case report associates porcine H. suis strains with gastric disease in humans, thus emphasizing the zoonotic importance of H. suis bacteria from pigs.

Helicobacter heilmannii sp. nov., isolated from feline gastric mucosa.

Three gram-negative, microaerophilic bacteria, strains ASB1(T), ASB2 and ASB3, with a corkscrew-like morphology isolated from the gastric mucosa of cats were studied using a polyphasic taxonomic approach. The isolates grew on biphasic culture plates under microaerobic conditions at 37 °C and exhibited urease, oxidase and catalase activities. They were also able to grow in colonies on dry agar plates. Based on 16S rRNA gene sequence analysis, ASB1(T), ASB2 and ASB3 were identified as members of the genus Helicobacter and showed 98 to 99 % sequence similarity to strains of Helicobacter felis, Helicobacter bizzozeronii, 'Candidatus Helicobacter heilmannii', Helicobacter cynogastricus, Helicobacter baculiformis and Helicobacter salomonis, six related Helicobacter species previously detected in feline or canine gastric mucosa. Sequencing of the partial hsp60 gene demonstrated that ASB1(T), ASB2 and ASB3 constitute a separate taxon among the feline and canine Helicobacter species. The urease gene sequences of ASB1(T), ASB2 and ASB3 showed approximately 91 % similarity to those of 'Candidatus Helicobacter heilmannii'. Protein profiling, the absence of alkaline phosphatase activity and several other biochemical characteristics also allowed strains ASB1(T), ASB2 and ASB3 to be differentiated from other Helicobacter species of feline or canine gastric origin. The results of this polyphasic taxonomic study show that the cultured isolates constitute a new taxon corresponding to 'Candidatus Helicobacter heilmannii', which was previously demonstrated in the stomach of humans, wild felidae, cats and dogs. The name Helicobacter heilmannii sp. nov. is proposed for these isolates; the type strain is ASB1(T) (=DSM 24751 (T) =LMG 26292(T)) [corrected].

Prevalence of non Helicobacter pylori species in patients presenting with dyspepsia.

BACKGROUND: Helicobacter species associated with human infection include Helicobacter pylori, Helicobacter heilmannii and Helicobacter felis among others. In this study we determined the prevalence of H. pylori and non-Helicobacter pylori organisms H. felis and H. heilmannii and analyzed the association between coinfection with these organisms and gastric pathology in patients presenting with dyspepsia. Biopsy specimens were obtained from patients with dyspepsia on esophagogastroduodenoscopy (EGD) for rapid urease test, histology and PCR examination for Helicobacter genus specific 16S rDNA, H. pylori phosphoglucosamine mutase (glmM) and urease B (ureB) gene of H. heilmannii and H. felis. Sequencing of PCR products of H. heilmannii and H. felis was done. RESULTS: Two hundred-fifty patients with dyspepsia were enrolled in the study. The mean age was 39 ± 12 years with males 162(65%). Twenty-six percent (66 out of 250) were exposed to cats or dogs. PCR for Helicobacter genus specific 16S rDNA was positive in 167/250 (67%), H. pylori glmM in 142/250 (57%), H. heilmannii in 17/250 (6%) and H. felis in 10/250 (4%), respectively. All the H. heilmannii and H. felis PCR positive patients were also positive for H. pylori PCR amplification. The occurrence of coinfection of H. pylori and H. heilmannii was 17(6%) and with H. felis was 10(4%), respectively. Only one out of 66 exposed to pets were positive for H. heilmannii and two for H. felis. Histopathology was carried out in 160(64%) of 250 cases. Chronic active inflammation was observed in 53(56%) (p = 0.001) of the patients with H. pylori infection alone as compared to 3(37%) (p = 0.73) coinfected with H. heilmannii and H. pylori and 3(60%) coinfected with H. felis and H. pylori (p = 0.66). Intestinal metaplasia was observed in 3(3%)(p = 1.0) of the patients with H. pylori infection alone as compared to 2(25%) (p = 0.02) coinfected with H. heilmannii and H. pylori and 1(20%) coinfected with H. felis and H. pylori (p = 0.15). CONCLUSION: The prevalence of H. heilmannii and H. felis was low in our patients with dyspepsia. Exposure to pets did not increase the risk of H. heilmannii or H. felis infection. The coinfection of H. pylori with H. heilmannii was seen associated with intestinal metaplasia, however this need further confirmation.

Helicobacter suis and Helicobacter pylori infection in a colony of research macaques: characterization and clinical correlates.

Introduction. Helicobacter suis (Helicobacter heilmannii type 1) commonly infects nonhuman primates but its clinical importance is in question.Aim. To characterize H. suis infection in a colony of rhesus macaques (Macaca mulatta) used in cognitive neuroscience research.Hypothesis/Gap Statement. Inquiries into the nature of Helicobacter suis in nonhuman primates are required to further define the organism's virulence and the experimental animal's gastric microbiome.Methodology. Animals with and without clinical signs of vomiting and abdominal pain (n=5 and n=16, respectively) were evaluated by histology, culture, PCR amplification and sequencing, fluorescent in situ hybridization (FISH) and serology. Three of the five animals with clinical signs, an index case and two others, were evaluated before and after antimicrobial therapy.Results. The index animal had endoscopically visible ulcers and multifocal, moderate, chronic lymphoplasmacytic gastritis with intraglandular and luminal spiral bacteria. Antimicrobial therapy in the index animal achieved histologic improvement, elimination of endoscopically visible ulcers, and evident eradication but clinical signs persisted. In the other treated animals, gastritis scores were not consistently altered, gastric bacteria persisted, but vomiting and abdominal discomfort abated.Nineteen of 21 animals were PCR positive for H. suis and five animals were also PCR positive for H. pylori. Organisms were detected by FISH in 17 of 21 animals: 16S rRNA sequences of two of these were shown to be H. suis. Mild to moderate lymphoplasmacytic gastritis was seen in antrum, body and cardia, with antral gastritis more likely to be moderate than that of the body.Conclusion. No clear association between the bacterial numbers of Helicobacter spp. and the degree of inflammation was observed. H. suis is prevalent in this colony of Macaca mulatta but its clinical importance remains unclear. This study corroborates many of the findings in earlier studies of H. suis infection in macaques but also identifies at least one animal in which gastritis and endoscopically visible gastric ulcers were strongly associated with H. suis infection. In this study, serology was an inadequate biomarker for endoscopic evaluation in diagnosis of H. suis infection.

Gastric Infection with Kazachstania heterogenica influences the outcome of a Helicobacter suis infection in Mongolian gerbils.

BACKGROUND: The Mongolian gerbil model is often used to investigate the interactions between different gastric Helicobacter species and the gastric tissue. A preliminary screening of a gerbil population intended for use in Helicobacter suis infection studies revealed a natural yeast infection in the stomach of these animals. After identification, we have investigated the effect of the gastric yeast infection on the outcome of an experimental H. suis infection in Mongolian gerbils. MATERIALS AND METHODS: Yeast cells were isolated from the stomachs of Mongolian gerbils. Identification was done by Internally Transcribed rRNA Spacer 2 Region PCR fragment length analysis. To investigate a possible pathologic role of this yeast, Mongolian gerbils were infected experimentally with this yeast. Co-infection with the newly isolated H. suis was performed to investigate possible interactions between both micro-organisms. RESULTS: Kazachstania heterogenica was found colonizing the stomach of Mongolian gerbils, mainly in the antrum. Few pathologic changes were seen in the stomachs of infected animals. Experimental co-infection of gerbils with this yeast and the newly isolated H. suis showed a significant increase in inflammation in animals infected with both micro-organisms compared to animals infected only with H. suis. CONCLUSIONS: K. heterogenica colonizes the stomach of Mongolian gerbils in exactly the same regions as gastric Helicobacter species. The uncontrolled presence of this yeast in the gerbil stomach can lead to an overestimation of the inflammation caused by Helicobacter in this animal model.

Distribution of Candidatus Liberibacter species in Eastern Africa, and the First Report of Candidatus Liberibacter asiaticus in Kenya.

Huanglongbing (HLB) is a serious disease of Citrus sp. worldwide. In Africa and the Mascarene Islands, a similar disease is known as African citrus greening (ACG) and is associated with the bacterium Candidatus Liberibacter africanus (Laf). In recent years, Candidatus Liberibacter asiaticus (Las) associated with the severe HLB has been reported in Ethiopia. Thus, we aimed to identify the Liberibacter species affecting citrus, the associated vectors in Eastern Africa and their ecological distribution. We assessed the presence of generic Liberibacter in symptomatic leaf samples by quantitative PCR. Subsequently, we sequenced the 50 S ribosomal protein L10 (rplJ) gene region in samples positive for Liberibacters and identified the species by comparison with public sequence data using phylogenetic reconstruction and genetic distances. We detected generic Liberibacter in 26%, 21% and 66% of plants tested from Uganda, Ethiopia and Kenya, respectively. The rplJ sequences revealed the most prevalent Liberibacters in Uganda and Ethiopia were LafCl (22%) and Las (17%), respectively. We detected Las in Kenya for the first time from three sites in the coastal region. Finally, we modelled the potential habitat suitability of Las in Eastern Africa using MaxEnt. The projection showed large areas of suitability for the pathogen in the three countries surveyed. Moreover, the potential distribution in Eastern Africa covered important citrus-producing parts of Ethiopia, Kenya, Uganda and Tanzania, and included regions where the disease has not been reported. These findings will guide in the development of an integrated pest management strategy to ACG/HLB management in Africa.

SMAD4 juvenile polyposis syndrome and hereditary haemorrhagic telangiectasia presenting in a middle-aged man as a large fungating gastric mass, polyposis in both upper and lower GI tract and iron deficiency anaemia, with no known family history.

Juvenile polyposis syndrome (JPS) and hereditary haemorrhagic telangiectasia (HHT) are rare autosomal dominant diseases, where symptoms manifest at childhood. A 32-year-old man with no family history of JPS or HHT with SMAD4 gene mutation who developed signs and symptoms only at the age of 32, when he was an adult. In this article, we highlight the steps taken to diagnose this rare pathology, explain its pathophysiology and management.

[Gastritis caused by Helicobacter heilmannii probably transmitted from dog to child]. / Gastrite àHelicobacter heilmannii probablement transmise à l'enfant par ses chiens.

Gastric infection with Helicobacter heilmannii is rare but is known to be associated with chronic active gastritis, peptic ulcer, and low-grade mucosa-associated lymphoid tissue lymphoma in humans. In contrast to H. pylori, various H. heilmannii species colonize the stomachs of domestic animals, which might be a reservoir for transmission to humans. We report the case of a 12-year-old boy presenting with chronic gastritis caused by H. heilmannii. Endoscopic examination reveals H. heilmannii-like infection on biopsy samples in his two pet dogs. Sequencing of the 16S and 23S ribosomal DNA by PCR was used to compare the H. heilmannii-like bacterial samples isolated in the boy and his dogs. These DNA amplification methods suggest that the boy was infected by his pet dogs (zoonosis). Our patient was cured by treatment with proton-pump inhibitor and antibiotics. Endoscopic follow-up of the boy showed a complete cure of gastritis and eradication of the bacterium.