An inverse and independent association between Helicobacter pylori infection and the incidence of shigellosis and other diarrheal diseases

CagA-positive Helicobacter pylori may promote and aggravate scrub typhus

Helicobacter pylori (H. pylori) infection may alter the host's resistance to tsutsugamushi disease pathogens through the Th1 immune response, leading to potential synergistic pathogenic effects. A total of 117 scrub typhus cases at Beihai People's Hospital and affiliated hospitals of Youjiang University for Nationalities and Medical Sciences were studied from January to December 2022, alongside 130 healthy individuals forming the control group. All participants underwent serum H. pylori antibody testing. The prevalence of H. pylori infection was significantly higher among scrub typhus patients (89.7%) compared to healthy individuals (54.6%) (p < 0.05). Moreover, type I H. pylori infection was notably more prevalent in scrub typhus cases (67.5%) compared to healthy individuals (30%) (p < 0.05). Multifactorial analysis demonstrated type I H. pylori infection as an independent risk factor for scrub typhus (adjusted odds ratio: 2.407, 95% confidence interval: 1.249-4.64, p = 0.009). Among scrub typhus patients with multiple organ damage, the prevalence of type I H. pylori infection was significantly higher (50.6%) than type II H. pylori infection (15.4%) (χ2 = 4.735, p = 0.030). These results highlight a higher incidence of H. pylori infection in scrub typhus patients compared to the healthy population. Additionally, type I H. pylori strain emerged as an independent risk factor for scrub typhus development. Moreover, individuals infected with type I H. pylori are more susceptible to multiple organ damage. These findings suggest a potential role of H. pylori carrying the CagA gene in promoting and exacerbating scrub typhus.

The global prevalence of and factors associated with Helicobacter pylori infection in children: a systematic review and meta-analysis

BACKGROUND

Synthesised data on the prevalence of, and factors associated with, paediatric Helicobacter pylori infection at the global level remain scarce. We aimed to estimate the global prevalence of H pylori infection and its associated factors in children and adolescents.

METHODS

In this systematic review and meta-analysis, we searched PubMed, Embase, MEDLINE, and Scopus for observational population-based studies published between database inception and Oct 25, 2021, without language or geographical restrictions. We included studies that reported the prevalence of H pylori infection in children aged 18 years or younger. Records were screened and data were extracted using a standardised extraction form. We estimated the worldwide prevalence of H pylori infection in children (our main outcome) using multilevel mixed-effects meta-regression and then stratified prevalence by diagnostic method (serology vs urea breath tests or stool antigen tests). We analysed the significance of associated factors using a random-effects meta-analysis. This study is registered in PROSPERO, CRD42020209717.

FINDINGS

We identified 3181 records, of which 198 articles with 632 data points from 152 650 children were included. The overall global prevalence of H pylori infection in children was 32·3% (95% CI 27·3-37·8), which varied by diagnostic test (28·6% [23·0-35·0] for serology vs 35·9% [29·2-43·2] for urea breath tests or stool antigen tests). Regardless of diagnostic test, the prevalence of H pylori infection was significantly higher in low-income and middle-income countries than in high-income countries (43·2% [36·5-50·2] vs 21·7% [16·9-27·4]; p<0·0001) and in older children than in younger children (41·6% [35·6-47·8] in 13-18-year-olds vs 33·9% [28·6-39·7] in 7-12-year-olds vs 26·0% [21·4-31·0] in 0-6-year-olds; p<0·0001). Paediatric H pylori infection was significantly associated with lower economic status (odds ratio [OR] 1·63 [95% CI 1·46-1·82]), more siblings or children (1·84 [1·44-2·36]), room sharing (1·89 [1·49-2·40]), no access to a sewage system (1·60 [1·22-2·10]), having a mother infected with H pylori (3·31 [2·21-4·98]), having a sibling or siblings infected with H pylori (3·33 [1·53-7·26]), drinking unboiled or non-treated water (1·52 [1·32-1·76]), and older age (OR per year 1·27 [1·15-1·40]).

INTERPRETATION

H pylori infection is still highly prevalent in children and adolescents globally. Our findings can help to guide further research and the development and implementation of preventive and therapeutic measures to reduce H pylori infection in children.

FUNDING

None.

Helicobacter pylori and association between its positivity and anatomotopographic settlement in the stomach with the host age range

Helicobacter pylori (H. pylori) is a Gram-negative, helically shaped flagellated bacterium. Major diseases associated with H. pylori infection include peptic ulcer, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma. The incidence of H. pylori in the anatomotopographic regions of the stomach, such as antrum, corpus, fundus, and incisura angularis, has been investigated. Do the rates of H. pylori in the settlements change over time according to the age ranges of the hosts? Does this change affect the diseases caused by or related to H. pylori? It is estimated that the outcomes, which have been obtained, may provide a new perspective in terms of understanding the etiopathogenesis of H. pylori-induced diseases. A comprehensive literature search of PubMed/MEDLINE databases had been conducted using a combination of terms, “Helicobacter pylori,” “Sydney System,” “stomach,” “pyloric antrum,” “gastric corpus,” “stomach cancer,” and “Helicobacter pylori and age.” There are very few articles examining the relationship between the topographic locations of H. pylori and host age range in the English language literature. Therefore, it is also purposed to emphasize the outcomes of our current research about the mentioned topic. In our opinion, similar studies should reveal the settlement and age range in the different geographic locations and societies as in our study. We believe that these findings will contribute to the efforts for understanding overtly of H. pylori-induced disease of the stomach.

Fecal Bacterial Microbiota of Healthy Free-Ranging, Healthy Corralled, and Chronic Diarrheic Corralled Rhesus Macaques (Macaca mulatta)

A clinical challenge to nearly every primate facility in North America is chronic idiopathic diarrhea (CID), the pathogenesis of which has yet to be fully elucidated. However, wild macaques appear resistant to CID, a trend that we observed in the free-ranging population of the Caribbean Primate Research Center. The gastrointestinal microbiota has been shown to have a significant role in the pathogenesis of disease and in maintaining normal health and development of the gut. In humans, chronic diarrhea is associated with alteration of the gut microbiota, which has lower bacterial diversity than does the microbiota of healthy humans. The current study was designed to describe and compare the fecal bacterial microbiota of healthy corralled, CID corralled, and healthy, free-ranging macaques. Fresh fecal samples were collected from healthy corralled (HC; n = 30) and CID (n = 27) rhesus macaques and from healthy macaques from our free-ranging colony (HF; n = 43). We excluded macaques that had received antibiotics during the preceding 60 d (90 d for healthy animals). Bacterial DNA was extracted, and the V4 region of the 16S rRNA gene was sequenced and compared with known databases. The relative abundance of Proteobacteria was higher in CID animals than HC animals, but otherwise few differences were found between these 2 groups. HF macaques were differentially enriched with Christensenellaceae and Helicobacter, which are highly associated with a 'healthy' gut in humans, as compared to corralled animals, whereas CID animals were enriched with Proteobacteria, which are associated with dysbiosis in other species. These results indicate that environment has a greater influence than health status on the gut microbiota. Furthermore, the current data provided targets for future studies on potential clinical interventions, such as probiotics and fecal transplants.

Pre-existing Helicobacter pylori serum IgG enhances the vibriocidal antibody response to CVD 103-HgR live oral cholera vaccine in Malian adults

Accumulating evidence indicates that persistent Helicobacter pylori gastric infection influences immune responses to oral enteric vaccines. We studied the association between pre-existing H. pylori serum IgG and serum pepsinogens levels (PGs) as markers of gastric inflammation and the immune response to single-dose live oral cholera vaccine CVD 103-HgR in Malian adults. Baseline sera obtained during a phase 2 safety/immunogenicity clinical trial of cholera vaccine CVD 103-HgR among 93 healthy Malian adults were tested for H. pylori IgG antibodies and PGI and PGII levels using enzyme linked immunosorbent assays. Overall 74/93 (80%) vaccine recipients were H. pylori IgG seropositive at baseline. Vibriocidal antibody seroconversion (≥ fourfold increase 14 days following administration of CVD 103-HgR compared to baseline) among vaccine recipients was 56%. However, vibriocidal antibody seroconversion was markedly higher among H. pylori seropositives than seronegatives 64% vs. 26% (p = 0.004); adjusted relative risk: 2.20 (95% confidence intervals 1.00–4.80; p = 0.049). Among H. pylori seropositive vaccine recipients, there were no significant associations between PGI, PGII and PGI:PGII levels and vibriocidal seroconversion. The enhanced seroconversion to oral cholera vaccine CVD 103-HgR among H. pylori seropositive African adults provides further evidence of the immunomodulating impact of H. pylori on oral vaccine immunogenicity.

Gastric hyperplastic polyps inversely associated with current Helicobacter pylori infection

The incidence of gastric hyperplastic polyps (HPs) has been on the rise in recent years. The contribution of Helicobacter pylori infection to this trend has remained to be elucidated. The present study aimed to explore the association between HPs and H. pylori in China, an area with a high infection rate of H. pylori. In order to study trends of HPs and H. pylori infection over the past decades, cases encountered from 2009 to 2018 were assessed and a total of 109,150 consecutive patients who underwent esophagogastroduodenoscopy at Qingdao Municipal Hospital (Qingdao, China) were enrolled. The incidence of HPs and the prevalence of H. pylori were determined and their correlation was explored. Gastric HPs were detected in 1,497 patients (1.6%) who received gastric biopsies. The incidence of HPs exhibited a rising trend, with a ~4-fold increase in the annual detection rate from 2009 to 2018. The prevalence of H. pylori infection was inversely associated with the prevalence of HPs (adjusted odds ratio, 0.66). The prevalence of H. pylori in the examined cohort decreased with time (r=-0.76, P=0.011). The decreasing trend of H. pylori infection was negatively correlated with the rising trend of HPs (r=-0.64, P=0.048), further indicating an inverse association between them. The difference in the prevalence of HPs between H. pylori-negative and -positive patients increased with age (r=0.80, P=0.018). The age-associated increase was slower in H. pylori-infected patients. The decline in H. pylori infection with time appeared to not be associated with the birth cohort effect, suggesting the decline was not caused by exposure to environmental factors during an early period of life. The present results indicated that the incidence of gastric HPs increased with the decline in H. pylori infection, demonstrating an inverse association between the occurrence of HPs and the infection.

Determining the association between fibromyalgia, the gut microbiome and its biomarkers: A systematic review

BACKGROUND

The association between fibromyalgia and irritable bowel syndrome is well-established. Alterations in the composition and diversity of the gut microbiome in irritable bowel syndrome have been reported, however, this association is poorly understood in fibromyalgia. Our aim was to summarise the research reporting on the gastrointestinal microbiome and its biomarkers in people with fibromyalgia.

METHODS

A systematic review of published original research reporting on the gastrointestinal microbiota and its biomarkers in adults with a diagnosis of fibromyalgia was undertaken.

RESULTS

From 4771 studies, 11 met our inclusion criteria and were separated into four main groups: papers reporting Helicobacter pylori; other gut bacterial markers; metabolomics and other biomarkers, which included intestinal permeability and small intestinal bacterial overgrowth.

CONCLUSION

The results suggest there is a paucity of quality research in this area, with indications that the gut microbiota may play a role in fibromyalgia within the emerging field of the gut-musculoskeletal axis. Further investigations into the relationship between the gut microbiota, gut dysfunction and fibromyalgia are warranted.

Clostridium difficile-associated disease and Helicobacter pylori seroprevalence: A case-control study

BACKGROUND

Helicobacter pylori inhabits the stomach and causes persistent inflammation, with changes in gastric acidity. However, it is unclear whether the presence of H pylori plays a role in Clostridium difficile-associated disease (CDAD). The study's aim was to examine relationships of H pylori seroprevalence and serum pepsinogens (PGs), as markers of gastric inflammation, with CDAD.

MATERIALS AND METHODS

A case-control study was conducted among 49 CDAD cases and 54 controls (median age 82 years). Using enzyme-linked immunosorbent assays, sera were tested for H pylori IgG antibody, and PGI and PGII levels. Helicobacter pylori-positive samples were tested for IgG antibody to recombinant cytotoxin-associated gene A (CagA) virulent protein. Logistic regression models were fitted.

RESULTS

Cases and controls were comparable in age (P = .5) and sex distribution (females 62% vs 57%, P = .6). Helicobacter pylori IgG seroprevalence was 47%, of whom 23% were CagA seropositives. Among cases compared to controls, 43% vs 28% were H pylori seropositive but lacking CagA IgG antibody: adjusted odd ratio (OR) 3.43 (95% confidence intervals [CI] 1.29-9.10); 18% vs 4% were positive for CagA phenotype: adjusted OR 9.32 (95% CI 1.61-53.76). This association was not affected by PG levels.

CONCLUSIONS

Helicobacter pylori infection, especially with CagA virulent phenotype, might predispose to C difficile infection in elderly patients.

Helicobacter pylori Infection Aggravates Dysbiosis of Gut Microbiome in Children With Gastritis

Introduction:Helicobacter pylori infection consistently leads to chronic and low degree of inflammatory response in gastric mucosa and is closely related with gastrointestinal and extra-gastric diseases. Effects of local microbiome in the stomach have been studied in adults and children with H. pylori infection. It is, however, not known whether the intestinal microbial community differs in children with varying H. pylori infection. The aim of this study is to characterize the altered composition of microbiome induced by H. pylori infection and in gastritis.

Materials and Methods: This study involved 154 individuals, including 50 children affected by H. pylori-induced gastritis, 42 children with H. pylori-negative gastritis, and 62 healthy controls. Gut microbiome composition was analyzed using 16S rRNA gene-based pyrosequencing. Fecal bacterial diversity and composition were then compared.

Results: On the basis of an analysis of similarities and differences, we found that children with H. pylori-induced gastritis exhibited gut bacteria dysbiosis. The ratio of Firmicutes/Bacteroidetes (F:B) at the phylum level had dramatically decreased in H. pylori-positive gastritis group (HPG) and H. pylori-negative gastritis group (HNG), compared with the healthy control group (HCG). At the family and genus levels, relative abundance of Bacteroidaceae and Enterobacteriaceae was prevalent in HPG and HNG, whereas relative abundance of Lachnospiraceae, Bifidobacteriaceae, and Lactobacillaceae was seen in HCG. Prevalence of different taxa of gut microbiome at the class, order, family, and genus levels was also observed among the three groups.

Conclusions: Gastritis can cause changes in composition of fecal microbiome, which is exacerbated by H. pylori infection. These changes in gut microbiome may be related to drug resistance and development of chronic gastrointestinal diseases.

Helicobacter pylori in human health and disease: Mechanisms for local gastric and systemic effects

Helicobacter pylori (H. pylori) is present in roughly 50% of the human population worldwide and infection levels reach over 70% in developing countries. The infection has classically been associated with different gastro-intestinal diseases, but also with extra gastric diseases. Despite such associations, the bacterium frequently persists in the human host without inducing disease, and it has been suggested that H. pylori may also play a beneficial role in health. To understand how H. pylori can produce such diverse effects in the human host, several studies have focused on understanding the local and systemic effects triggered by this bacterium. One of the main mechanisms by which H. pylori is thought to damage the host is by inducing local and systemic inflammation. However, more recently, studies are beginning to focus on the effects of H. pylori and its metabolism on the gastric and intestinal microbiome. The objective of this review is to discuss how H. pylori has co-evolved with humans, how H. pylori presence is associated with positive and negative effects in human health and how inflammation and/or changes in the microbiome are associated with the observed outcomes.

Does Helicobacter pylori Infection Play a Role in Susceptibility to Brucellosis?

Brucellosis is endemic in Iran. Several studies have shown that brucellosis is associated with other infectious diseases. This study aimed to determine the relationship between Helicobacter pylori (HP) and brucellosis. In this case-control study, 100 patients with brucellosis as cases and 200 participants without brucellosis as controls were evaluated. To compare the prevalence of HP in the 2 groups, odds ratios and confidence intervals for every variable were analyzed using logistic regression models after adjustment for confounding factors. The results obtained in patients with brucellosis showed that fever, sweating, and joint pain were the most prevalent clinical symptoms. In addition, compared with the control group, there was a significant relationship between the IgM antibody to HP and brucellosis infection (estimated odds ratio 2.74; 95% CI: 1.5-4.9) (p = 0.001). Acute infection with HP was associated with brucellosis and increased the risk of brucellosis infection.

Silane Modified Diopside for Improved Interfacial Adhesion and Bioactivity of Composite Scaffolds

Diopside (DIOP) was introduced into polyetheretherketone/polyglycolicacid (PEEK/PGA) scaffolds fabricated via selective laser sintering to improve bioactivity. The DIOP surface was then modified using a silane coupling agent, 3-glycidoxypropyltrimethoxysilane (KH570), to reinforce interfacial adhesion. The results showed that the tensile properties and thermal stability of the scaffolds were significantly enhanced. It could be explained that, on the one hand, the hydrophilic group of KH570 formed an organic covalent bond with the hydroxy group on DIOP surface. On the other hand, there existed relatively high compatibility between its hydrophobic group and the biopolymer matrix. Thus, the ameliorated interface interaction led to a homogeneous state of DIOP dispersion in the matrix. More importantly, an in vitro bioactivity study demonstrated that the scaffolds with KH570-modified DIOP (KDIOP) exhibited the capability of forming a layer of apatite. In addition, cell culture experiments revealed that they had good biocompatibility compared to the scaffolds without KDIOP. It indicated that the scaffolds with KDIOP possess potential application in tissue engineering.

Gastric Helicobacter pylori Infection Affects Local and Distant Microbial Populations and Host Responses

Helicobacter pylori is a late-in-life human pathogen with potential early-life benefits. Although H. pylori is disappearing from the human population, little is known about the influence of H. pylori on the host's microbiota and immunity. Studying the interactions of H. pylori with murine hosts over 6 months, we found stable colonization accompanied by gastric histologic and antibody responses. Analysis of gastric and pulmonary tissues revealed increased expression of multiple immune response genes, conserved across mice and over time in the stomach and more transiently in the lungs. Moreover, H. pylori infection led to significantly different population structures in both the gastric and intestinal microbiota. These studies indicate that H. pylori influences the microbiota and host immune responses not only locally in the stomach, but distantly as well, affecting important target organs.

An inverse association of Helicobacter pylori infection with oral squamous cell carcinoma

BACKGROUND

Few studies have focused on the relationship between Helicobacter pylori (H. pylori) infection and oral diseases. In this study, we explored the correlation between H. pylori infection and oral squamous cell carcinoma (OSCC).

METHODS

A total of 68 patients with OSCC and 104 age- and sex- matched healthy control subjects were retrospectively enrolled in this study. The H. pylori immunoglobin (Ig) G antibodies in serum were detected by enzyme-linked immunosorbent assay (ELISA) method to assess the status of H. pylori infection of our study sample. Polymerase chain reaction (PCR) was also employed using H. pylori genus-specific 16S rRNA primers in fasting blood, and OSCC specimens were analyzed by histochemical stain of each enrolled subject. The strength of correlation between H. pylori and the development of OSCC was estimated by Spearman's correlation coefficient.

RESULTS

According to the three methods for detecting prevalence of H. pylori infection in the patients with OSCC, it was statistically lower than that in the healthy controls (35.3% vs. 54.8%, P = 0.012). An inverse correlation was observed between H. pylori infection and OSCC development (Spearman's correlation coefficient = -0.191, P = 0.012). In stratification analysis, we also found a statistical association between H. pylori infection and OSCC in the subpopulation with age ≥ 60 years (P = 0.037).

CONCLUSION

Our findings suggested that H. pylori infection may be negatively related to OSCC. A reverse association of H. pylori infection with OSCC risk in the subpopulation with age ≥ 60 years was also found.

Friend and foe: factors influencing the movement of the bacterium Helicobacter pylori along the parasitism-mutualism continuum

Understanding the transition of bacterial species from commensal to pathogen, or vice versa, is a key application of evolutionary theory to preventative medicine. This requires working knowledge of the molecular interaction between hosts and bacteria, ecological interactions among microbes, spatial variation in bacterial prevalence or host life history, and evolution in response to these factors. However, there are very few systems for which such broad datasets are available. One exception is the gram-negative bacterium, Helicobacter pylori, which infects upwards of 50% of the global human population. This bacterium is associated with a wide breadth of human gastrointestinal disease, including numerous cancers, inflammatory disorders, and pathogenic infections, but is also known to confer fitness benefits to its host both indirectly, through interactions with other pathogens, and directly. Outstanding questions are therefore why, when, and how this bacterium transitions along the parasitism–mutualism continuum. We examine known virulence factors, genetic predispositions of the host, and environmental contributors that impact progression of clinical disease and help define geographical trends in disease incidence. We also highlight the complexity of the interaction and discuss future therapeutic strategies for disease management and public health in light of the longstanding evolutionary history between the bacterium and its human host.

First detected Helicobacter pylori infection in infancy modifies the association between diarrheal disease and childhood growth in Peru

BACKGROUND

In endemic settings, Helicobacter pylori infection can occur shortly after birth and may be associated with a reduction in childhood growth.

MATERIALS AND METHODS

This study investigated what factors promote earlier age of first H. pylori infection and evaluated the role of H. pylori infection in infancy (6-11 months) versus early childhood (12-23 months) on height. We included 183 children near birth from a peri-urban shanty town outside of Lima, Peru. Field-workers collected data on socioeconomic status (SES), daily diarrheal and breast-feeding history, antibiotic use, anthropometrics, and H. pylori status via carbon 13-labeled urea breath test up to 24 months after birth. We used a proportional hazards model to assess risk factors for earlier age at first detected infection and linear mixed-effects models to evaluate the association of first detected H. pylori infection during infancy on attained height.

RESULTS

One hundred and forty (77%) were infected before 12 months of age. Lower SES was associated with earlier age at first detected H. pylori infection (low vs middle-to-high SES Hazard ratio (HR) 1.59, 95% CI 1.16, 2.19; p = .004), and greater exclusive breast-feeding was associated with reduced likelihood (HR 0.63, 95% CI 0.40, 0.98, p = .04). H. pylori infection in infancy was not independently associated with growth deficits (p = .58). However, children who had their first detected H. pylori infection in infancy (6-11 months) versus early childhood (12-23 months) and who had an average number of diarrhea episodes per year (3.4) were significantly shorter at 24 months (-0.37 cm, 95% CI, -0.60, -0.15 cm; p = .001).

DISCUSSION

Lower SES was associated with a higher risk of first detected H. pylori infection during infancy, which in turn augmented the adverse association of diarrheal disease on linear growth.

The impoverished gut--a triple burden of diarrhoea, stunting and chronic disease

More than one-fifth of the world's population live in extreme poverty, where a lack of safe water and adequate sanitation enables high rates of enteric infections and diarrhoea to continue unabated. Although oral rehydration therapy has greatly reduced diarrhoea-associated mortality, enteric infections still persist, disrupting intestinal absorptive and barrier functions and resulting in up to 43% of stunted growth, affecting one-fifth of children worldwide and one-third of children in developing countries. Diarrhoea in children from impoverished areas during their first 2 years might cause, on average, an 8 cm growth shortfall and 10 IQ point decrement by the time they are 7-9 years old. A child's height at their second birthday is therefore the best predictor of cognitive development or 'human capital'. To this 'double burden' of diarrhoea and malnutrition, data now suggest that children with stunted growth and repeated gut infections are also at increased risk of developing obesity and its associated comorbidities, resulting in a 'triple burden' of the impoverished gut. Here, we Review the growing evidence for this triple burden and potential mechanisms and interventions that must be understood and applied to prevent the loss of human potential and unaffordable societal costs caused by these vicious cycles of poverty.

Effectiveness of rifaximin and fluoroquinolones in preventing travelers' diarrhea (TD): a systematic review and meta-analysis

BACKGROUND

Recent developments related to a safe and effective nonabsorbable antibiotic, rifaximin, and identification of postinfectious irritable bowel syndrome as a frequent sequela call for a need to reconsider the value of primary prevention of traveler's diarrhea (TD) with antibiotics.

METHODS

Randomized, placebo-controlled, double-blind studies evaluating the effectiveness and safety of rifaximin or a fluoroquinolone chemoprophylaxis against TD were pooled using a random effects model and assessed for heterogeneity.

RESULTS

The nine studies (four rifaximin and five fluoroquinolone) included resulted in pooled relative risk estimates of 0.33 (95% CI = 0.24-0.45, I2 = 3.1%) and 0.12 (95% CI = 0.07-0.20, I2 =0.0%), respectively. Similar rates of treatment emergent adverse events were found between antibiotic and placebo groups.

CONCLUSIONS

This meta-analysis supports the effectiveness of antibiotics in preventing TD. However, further studies that include prevention of secondary chronic health outcomes among travelers to different geographic regions, and a formal risk-benefit analysis for antibiotic chemoprophylaxis, are needed.

Serologic host response to Helicobacter pylori and Campylobacter jejuni in socially housed Rhesus macaques (Macaca mulatta)

Background

Helicobacter pylori are successful colonizers of the human gastric mucosa. Colonization increases the risk of peptic ulcer disease and adenocarcinoma. However, potential benefits of H. pylori colonization include protection against early-onset asthma and against gastrointestinal infections. Campylobacter jejuni are a leading cause of bacterial diarrhea and complications include Guillain-Barré syndrome. Here, we describe the development of reliable serological assays to detect antibodies against those two bacteria in Rhesus macaques and investigated their distribution within a social group of monkeys.

Methods

Two cohorts of monkeys were analyzed. The first cohort consisted of 30 monkeys and was used to establish an enzyme-linked immunosorbent assay (ELISA) for H. pylori antibodies detection. To evaluate colonization of those macaques, stomach biopsies were collected and analyzed for the presence of H. pylori by histology and culture. C. jejuni ELISAs were established using human serum with known C. jejuni antibody status. Next, plasma samples of the 89 macaques (Cohort 2) were assayed for antibodies and then statistically analyzed.

Results

An H. pylori IgG ELISA, which was 100% specific and 93% sensitive, was established. In contrast, the IgA ELISA was only 82% specific and 61% sensitive. The CagA IgG assay was 100% sensitive and 61% of the macaques were positive. In cohort 2, 62% macaques were H. pylori sero-positive and 52% were CagA positive. The prevalence of H. pylori IgG and CagA IgG increased with monkey age as described for humans. Of the 89 macaques 52% showed IgG against C. jejuni but in contrast to H. pylori, the sero-prevalence was not associated with increasing age. However, there was a drop in the IgG (but not in IgA) mean values between infant and juvenile macaques, similar to trends described in humans.

Conclusions

Rhesus macaques have widespread exposure to H. pylori and C. jejuni, reflecting their social conditions and implying that Rhesus macaques might provide a model to study effects of these two important human mucosal bacteria on a population.