Using macro-arrays to study routes of infection of Helicobacter pylori in three families

BACKGROUND

Analysis of the evolutionary dynamics of Helicobacter pylori allowed tracing the spread of infection through populations on different continents but transmission pathways between individual humans have not been clearly described.

MATERIALS AND METHODS

To investigate person-to-person transmission, we studied three families each including one child with persistence of symptoms after antibiotic treatment. Ten isolates from the antrum and corpus of stomach of each family member were analyzed both by sequencing of two housekeeping genes and macroarray tests.

RESULTS

A total of 134 (8.4%) out of the 1590 coding sequences (CDSs) tested, including cag PAI and insertion sequences, were present in some but not all isolates (and are therefore defined as variable CDSs). Most of the variable CDSs encoded proteins of unknown function (76/134) or were selfish DNA including that encoding restriction/modification enzymes (13/134). Isolates colonizing the stomach of one individual can vary by point mutations, as seen in hspA, or by the gain or loss of one to five CDSs. They were considered as (genetic) variants. The phylogenetic clustering of gene profiles obtained on macro-arrays allowed identifying the different strains infecting families. Two to five strains circulated within a family. Identical strains were present in at least two members of all three families supporting the accepted model of intrafamilial transmission. Surprisingly, the mother was not implicated in the transmission of H. pylori in the two French families. Sibling-to-sibling transmission and acquisition of H. pylori from outside the family appeared to be probable in the transmission pathways.

CONCLUSION

Macroarray analysis based on previously selected CDSs gives a comprehensive view of the genome diversity of a pathogen. This approach combined with information on the origin of the hspA and glmM alleles revealed that Helicobacter pylori infection may be acquired by more diverse routes than previously expected.

Helicobacter pylori infection in Canadian and related Arctic Aboriginal populations

In 2006, the Canadian Helicobacter Study Group identified Aboriginal communities among Canadian population groups most at risk of Helicobacter pylori-associated disease. The objective of this systematic review was to summarize what is known about the H pylori-associated disease burden in Canadian and related Arctic Aboriginal populations to identify gaps in knowledge. Six health literature databases were systematically searched to identify reports on H pylori prevalence in Canadian population groups, or any topic related to H pylori in Canadian Aboriginals, Alaska Natives or Aboriginals of other Arctic regions. Identified reports were organized by subtopic and summarized in narrative form. Key data from studies of H pylori prevalence in defined populations were summarized in tabular form. A few Arctic Aboriginal communities were represented in the literature: two Canadian Inuit; one Canadian First Nation; two Greenland Inuit; one Russian Chutkotka Native; and several Alaska Native studies. These studies uniformly showed elevated H pylori prevalence; a few studies also showed elevated occurrence of H pylori-related diseases and high rates of treatment failure. Based on the evidence, it would be warranted for clinicians to relax the criteria for investigating H pylori and related diseases in patients from Arctic Aboriginal communities, and to pursue post-therapy confirmation of eradication. Additional community-based research is needed to develop public health policies for reducing H pylori-associated health risks in such communities.

Prevalence of Helicobacter pylori in children and their family members in a district in Turkey

The aim of this study was to determine the prevalence of Helicobacter pylori among children and their family members and to evaluate some epidemiologic characteristics. The study included 275 children, aged 1-15 year(s), suffering from different gastrointestinal complaints. Blood serology and stool antigen testing were used for the diagnosis of infection due to H. pylori. Sixty-five (23.6%) of the 275 children were positive for H. pylori, and this positivity had a significantly increasing correlation with age (p<0.001). H. pylori-associated infection was observed among 45 (69.2%) and 17 (8%) mothers in the H. pylori-infected and non-infected groups respectively (p<0.0001). Most children and their families infected with H. pylori were living in an urban area. The findings suggest that infection due to H. pylori is a problem for this district area, and all children having any gastrointestinal complaints should be examined whether H. pylori was prevalent among their family members.

Association between Helicobacter pylori infection in mothers and birth weight

Helicobacter pylori infection may cause intrauterine growth restriction (IUGR). However, it is unknown whether the growth of children from H. pylori-infected mothers is also affected or whether transmission of infection from mother to child occurs. This study aimed to determine if maternal H. pylori infection was associated with IUGR and low birth weight in a mouse model, and whether transmission of infection from mother to infant occurs. Female C57BL/6 mice were inoculated with H. pylori (n = 18) or water (control; n = 18) via gavage. Mice were mated at 6 weeks postinfection, with half of the mice sacrificed after 2 weeks of gestation. The remaining mice gave birth and a third of the litter was weighed and sacrificed at birth, during milk feeding (1.5 weeks), and during solid feeding (4 weeks). Stomachs of all mice and whole foetuses were cultured for the presence of H. pylori. There were no differences in litter size or foetus weight between control and H. pylori-infected mice. Pups from infected mothers had a lower weight during milk feeding (control, 5.91 +/- 0.23 g; H. pylori, 4.59 +/- 0.16 g; p < 0.05) and solid feeding (control, 12.73 +/- 0.58 g; H. pylori, 10.01 +/- 1.02 g; p < 0.05). H. pylori was not detected by culture in the pups at any age. H. pylori infection in mothers was associated with a decrease in infant weight during milk feeding and after weaning. Transmission of infection from mother to infant was not detected by culture, suggesting that decreased baby weight may be due to decreased milk supply or altered nutrition from the mother.

Epidemiology of Helicobacter pylori infection

Helicobacter pylori infection is typically acquired in early childhood in both low- and high-income regions of the world and, once established, commonly persists lifelong unless treated. Social and economic development decreases the prevalence both within and between countries. The epidemiology of H. pylori infection highlights the geographic, ethnic, and racial differences throughout the world.

Effect of sibling number in the household and birth order on prevalence of Helicobacter pylori: a cross-sectional study

BACKGROUND

Infection with Helicobacter pylori (H. pylori) is acquired mainly in childhood, with studies demonstrating this is related to living conditions. Effects of sibling number and birth order on prevalence of infection have not been extensively studied.

METHODS

The authors performed a cross-sectional survey of adults, aged between 50 and 59 years, previously involved in a community-screening programme for H. pylori in Leeds and Bradford, UK. Prevalence of H. pylori was assessed at baseline with urea breath test. All individuals who were alive, and could be traced, were contacted by postal questionnaire in 2003 obtaining information on number of siblings and birth order. Data concerning childhood socioeconomic conditions were stored on file from the original study.

RESULTS

3928 (47%) of 8407 original participants provided data. Prevalence of infection increased according to sibling number (20% in those with none vs 63% with eight or more). Controlling for childhood socioeconomic conditions and birth order using multivariate logistic regression, infection odds were substantially increased with three siblings compared with none [odds ratio (OR) 1.51; 95% confidence interval (CI) 1.06-2.15], and a gradient of effect continued up to eight or more siblings (OR 5.70; 95% CI 2.92-11.14). Odds of infection also increased substantially with birth order, but the positive gradient disappeared on adjustment for sibling number and childhood socioeconomic conditions.

CONCLUSIONS

: In this cross section of UK adults, aged 50-59 years, sibling number in the household, but not birth order, was independently associated with prevalence of H. pylori infection.

A new model for the transmission of Helicobacter pylori: role of environmental reservoirs as gene pools to increase strain diversity

Twenty-five years after the first successful cultivation and isolation of Helicobacter pylori, the scientific community is still struggling to understand the way(s) this bacterium is transmitted among the human population. Here, both epidemiologic and microbiologic evidence addressing this matter is reviewed and explored to conclude that most H. pylori successful colonizations are derived from direct person-to-person contact and that even though exposure of humans to H. pylori from environmental sources is a very common event, in most occasions the host is able to fight off infection. In addition, under a new model developed here, we propose that the near elimination of environmental reservoirs is the main responsible for the lower prevalence observed in the more industrialized countries by acting on two levels: by decreasing the number of direct infections and by diminishing the number of intraspecies recombination events for producing strain variation within H. pylori.

Signaling perturbations induced by invading H. pylori proteins in the host epithelial cells: a mathematical modeling approach

Helicobacter pylori (H. pylori), a gram-negative bacterium, infects the stomach of approximately 50% of the world population. H. pylori infection is a risk factor for developing chronic gastric ulcers and gastric cancer. The bacteria produce two main cytotoxic proteins: Vacuolating cytotoxin A (VacA) and Cytotoxin-Associated gene A (CagA). When these proteins enter the host cell they interfere with the host MAP Kinase and Apoptosis signaling pathways leading to aberrant cell growth and premature apoptosis. The present study expanded existing quantitative models of the MAP Kinase and Apoptosis signaling pathways to take into account the protein interactions across species using the CellDesigner tool. The resulting network contained hundreds of differential equations in which the coefficients for the biochemical rate constants were estimated from previously published studies. The effect of VacA and CagA on the function of this network were simulated by increasing levels of bacterial load. Simulations showed that increasing bacterial load affected the MAP Kinase signaling in a dose dependant manner. The introduction of CagA decreased the activation time of mapK signaling and extended activation indefinitely despite normal cellular activity to deactivate the protein. Introduction of VacA produced a similar response in the apoptosis pathway. Bacterial load activated both pathways even in the absence of external stimulation. Time course of emergence of transcription factors associated with cell division and cell death predicted by our simulation showed close agreement with that determined from a publicly accessible microarray data set of H. pylori infected stomach epithelium. The quantitative model presented in this study lays the foundation for investigating the affects of single nucleotide polymorphisms (SNPs) on the efficiency of drug treatment.

Impact of household hygiene and water source on the prevalence and transmission of Helicobacter pylori: a South Indian perspective

INTRODUCTION

In developing countries, the Helicobacter pylori (H. pylori) infection rate is high, especially in lower socioeconomic groups. The populace in developing countries lives in conditions that are highly conducive to the acquisition of microorganisms. Poor hygiene, crowded household conditions and deficient sanitation mark their day-to-day life. We aimed to find out the roles of household hygiene and water source in the prevalence and transmission of H. pylori infection among the South Indian population using polymerase chain reaction (PCR) assay.

METHODS

The selected population consisted of 500 adults of varying ages ranging from 30 to 79 years, with upper gastrointestinal tract symptoms. Each participant in the study was given a questionnaire to complete. Samples to assess H. pylori infection included three gastric biopsies (two from the antrum and one from the corpus region). Infection was detected by PCR amplification of the 16S rRNA gene of H. pylori. The data was then examined statistically by univariate and multivariate analyses.

RESULTS

The overall prevalence of H. pylori was detected to be 80 percent. Prevalence increased with an increase in age and it was found to be 90 percent in the 70-79 year age group (p-value is less than 0.01). The prevalence of infection among people who drank water from wells was 92 percent compared with 74.8 percent of those who drank tap water (p-value is less than 0.001). H. pylori infection prevalence was found to be higher in people with low clean water index (CWI) (88.2 percent) than in those with higher CWI (33.3 percent) (p-value is less than 0.001). While the prevalence of H. pylori in the subjects with lower socioeconomic status was 86.1 percent, in higher groups, it was 70 percent (p-value is less than 0.001). The prevalence of H. pylori was also found to be higher in subjects who lived in overcrowded houses. It was 83.7 percent with high crowding index, 76.6 percent with medium crowding index, and 71.3 percent with low crowding index (p-value is less than 0.05).

CONCLUSION

The results of the present study suggest that the risk of acquisition and transmission of H. pylori can be prevented to a large extent by following improved household hygienic practices, proper waste disposal measures as well as the regular use of boiling water for drinking purposes.

Helicobacter pylori eradication for low-grade gastric mucosa-associated lymphoid tissue lymphoma is more successful in inducing remission in distal compared to proximal disease

A series of studies has shown that Helicobacter pylori eradication induces remission in most patients with low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma. However, there have been few reports about the effect of bacterial treatment on the gastric MALT lymphoma in Korea, a well-known H. pylori endemic area. A total of 111 H. pylori-infected patients were prospectively enrolled in Seoul National University Hospital and 99 among them were completely followed up according to our protocol. After H. pylori eradication, tumoural response was evaluated by endoscopy and histopathology every 2–3 months till complete remission (CR) and every 6 months after achieving CR. Median follow-up period was 41 months (range, 11–125 months). Helicobacter pylori was successfully eradicated in all 99 patients and CR was obtained in 84 (84.8%) of 99 patients. The median time to reach CR was 3 months and 94% of CR is in continuous complete remission. Five patients with CR relapsed after 10–22 months without the evidence of H. pylori reinfection. Cumulative recurrence rate was 2.3, 7.7 and 9.3% at 1, 2 and 3 years, respectively. Tumours were mainly located in distal stomach (67.7%) and tumours in distal stomach were associated with more favourable response than those in proximal stomach (P=0.001). Majority of patients with low-grade gastric MALT lymphoma treated by exclusive H. pylori eradication have a favourable long-term outcome, offering a real chance of cure. Tumour location could be a predictive factor for remission following H. pylori eradication.

Epidemiology of Helicobacter pylori infection

Helicobacter pylori infection is now recognised as a worldwide problem. It is the most common cause of chronic gastritis, and is strongly linked to peptic ulcer disease and gastric cancer. While the infection is usually acquired in childhood, there is typically a long period of latency with disease manifestations not appearing until adulthood. Gastric cancer does not usually manifest until old age. The infection has a high morbidity rate, but a low mortality rate and is curable with antibiotic therapy.

Intrafamilial transmission of Helicobacter pylori among the population of endemic areas in Japan

BACKGROUND

Helicobacter pylori (H. pylori) infection is a worldwide phenomenon related to several gastrointestinal diseases. However, because many aspects concerning the route of transmission remain unclear, we performed this epidemiologic study to clarify the route of intrafamilial transmission of H. pylori.

MATERIALS AND METHODS

A retrospective study was performed in three widely separate areas in Japan to investigate the prevalence of H. pylori infection. In 1993, 613 residents were tested as were 4136 in 2002, including 1447 family members of 625 families. Antibody to H. pylori (anti-H. pylori) was determined by enzyme-linked immunosorbent assay.

RESULTS

In 2002, the age-adjusted anti-H. pylori prevalence in Hoshino Village (67.5%) was significantly higher than in Kasuya Town (55.0%) and in Ishigaki City (54.7%) (p < .0001, p = .0039, respectively). The age-adjusted anti-H. pylori prevalence of Ishigaki City significantly decreased from 1993 (68.4%) to 2002 (52.5%), showing an age cohort effect. However, the prevalence did not significantly differ in children aged 0-6 years of Ishigaki City between 1993 (9.6%) and 2002 (10.3%). A familial analysis in 2002 demonstrated that the prevalence of anti-H. pylori was significantly higher in children with anti-H. pylori-positive (21.6%, 22 of 102) than with -negative mothers (3.2%, 3 of 95) (p < .0001, by Mantel-Haenszel test), whereas there was no significant difference between children with anti-H. pylori-positive and -negative fathers. Moreover, the prevalence was significantly higher in wives with anti-H. pylori-positive (64.0%, 208 of 325) than with -negative husbands (46.5%, 80 of 172) (p = .0071, by Mantel-Haenszel test) and in husbands with anti-H. pylori-positive (72.2%, 208 of 288) than with -negative wives (56.0%, 117 of 209) (p = .0106, by Mantel-Haenszel test).

CONCLUSIONS

In the last decade, H. pylori infection decreased in the general population of Japan by improvement of general hygiene conditions, but did not differ in young children, most likely because of mother-to-child transmission.

The transmission of Helicobacter pylori: the effects of analysis method and study population on inference

Although much is known about the virulence of Helicobacter pylori, the transmission pathways for this bacterium are still unresolved. Transmission has been addressed through: (1) prevalence within families; (2) detection in fecal/oral environments; (3) detection in the abiotic/biotic environment; and (4) direct inference from strain similarity. Here, we review the molecular and biochemical methods used and discuss the relative merits of each. Furthermore, as there are differences between developing and developed nations, we discuss the results obtained from transmission studies in light of the study population. We conclude that H. pylori is probably transmitted person-to-person, facilitated by fecal-oral transmission during episodes of diarrhea or gastro-oral contact during periods of vomiting. The persistence of H. pylori in abiotic and biotic environments remains unproven but possible reactivation from viable, non-culturable coccoid forms should be further investigated. Finally, we speculate on the effect of host-pathogen interactions in confounding the inference of transmission.

Tonsillar colonization is unlikely to play important role in Helicobacter pylori infection in children

OBJECTIVE

To determine (i) seroprevalence of Helicobacter pylori (HP) infection in children undergoing tonsillectomy, (ii) possible HP colonization on tonsils of children and its importance in HP transmission, and (iii) if four examined socio-economic factors are the risk factors for HP transmission and HP colonization on tonsils in children.

METHODS

Rapid urease test (RUT) of tonsils, and serologic blood tests for HP were performed in 77 children (aged 4-14 years) in Bosnia and Herzegovina (B-H), undergoing tonsillectomy. RUT positive tonsils were cultured for HP. RUT positive children were tested using (13)Carbon-urea breath test ((13)C-UBT). Information about socio-economic potential risk factors was obtained from the parents.

RESULTS

Out of 139 pharyngeal and palatine tonsils, 17 palatine tonsils in 14 children were RUT positive and had negative HP culture. Eight children had positive both RUT and (13)C-UBT. There was no significant difference between children with hypertrophy and those with recurrent tonsillitis comparing their serologic tests results. There was no significant difference between seronegative (n=61) and seropositive (n=16) children comparing their age, sex, parental education level, owning a family courtyard, attending a children's collective, and owning a pet cat.

CONCLUSIONS

The results in this prospective study do not support the notion that tonsils are an important reservoir for HP transmission in children in B-H. The examined socio-economic factors did not enhance HP seropositivity rate in children.

Rederivation of Helicobacter hepaticus-infected Mongolian gerbils by Caesarean section and cross-fostering to rats and mice

The Mongolian gerbil serves as an animal model for a wide range of diseases. As these animals are extensively used for the study of Helicobacter pylori-induced gastritis, naturally occurring infections with rodent Helicobacter species in gerbils are a possible source of interference in studies of H. pylori-associated disease. The gerbil stock at the Central Animal Facility in Hannover was persistently infected with H. hepaticus. The aim of this study was to derive Helicobacter species-free Mongolian gerbils. Therefore, germfree gerbil pups were obtained by Caesarean section and the pups were transferred to female rats and mice with recently delivered litters. In total, four Ztm:NMRI mice, four Ztm:SPRD rats and one DA/Ztm rat that originated from a specified pathogen-free area were selected to serve as foster mothers. With this approach, it was possible to obtain Helicobacter-free gerbils. Rearing by mice was more successful than by rats, as six of nine gerbils were reared by mice, but only one of 29 gerbils was reared by rats.

Gastroenteritis and transmission of Helicobacter pylori infection in households

The mode of transmission of Helicobacter pylori infection is poorly characterized. In northern California, 2,752 household members were tested for H. pylori infection in serum or stool at a baseline visit and 3 months later. Among 1,752 person considered uninfected at baseline, 30 new infections (7 definite, 7 probable, and 16 possible) occurred, for an annual incidence of 7% overall and 21% in children <2 years of age. Exposure to an infected household member with gastroenteritis was associated with a 4.8-fold (95% confidence interval [CI] 1.4-17.1) increased risk for definite or probable new infection, with vomiting a greater risk factor (adjusted odds ratio [AOR] 6.3, CI 1.6-24.5) than diarrhea only (AOR 3.0, p = 0.65). Of probable or definite new infections, 75% were attributable to exposure to an infected person with gastroenteritis. Exposure to an H. pylori-infected person with gastroenteritis, particularly vomiting, markedly increased risk for new infection.

Elevated 13C urea breath test values females infected with Helicobacter pylori

(13)C-urea breath test (UBT) for the diagnosis of Helicobacter pylori requires a high density and active bacteria and has the potential to provide a noninvasive index of bacterial growth. We describe the gender differences in delta over baseline (13)C-UBT values in 7373 patients (4531 females and 2842 males) who underwent (13)C-UBT test for the diagnosis of H. pylori infection. A significantly (P<.001) higher mean +/- SD excess delta (13)CO(2) excretion was recorded in females (24.7+/-17.4) compared to males (17.6+/-11.8) aged 10-80 years. The age-adjusted difference between sexes was 7.1 (95% confidence interval, 6.4-7.9). Our analysis demonstrates quantitatively for the first time gender associated differences in H. pylori host interaction. This study suggests that infected females have a higher bacterial load and therefore may potentially infect their children at a higher degree than males.

Community-based familial study of Helicobacter pylori infection among healthy Japanese Brazilians

BACKGROUND

The present study of Helicobacter pylori infection was conducted in family units of Japanese Brazilians living in São Paulo city. The authors attempted to determine the seroprevalence of H. pylori infection within family units of Japanese Brazilians and to identify risk factors associated with intrafamilial transmission.

METHODS

The seroprevalence was determined in 1037 healthy and asymptomatic volunteer subjects aged 0-69 years (530 adults and 507 children) of 265 families. Demographic data and details of living conditions were obtained from each family.

RESULTS

H. pylori seropositive infection was found in 39.2% of the parents and 9.3% of the children. A reduced risk of H. pylori infection was found for girls (odds ratio [OR] 0.45; 95% confidence interval [CI], 0.23-0.86). The prevalence of infection was 3.5% for children with uninfected parents; 9.9% (OR, 2.51; 95% CI, 0.95-6.61) for those with a seronegative mother and a seropositive father; 14.9% (OR, 4.93; 95% CI, 1.86-13.06) for those with a seropositive mother and a seronegative father; and 16.0% (OR, 5.29; 95% CI, 1.98-14.14) for those with seropositive parents. On multivariate analysis, the use of a pacifier, and mother's symptoms of nausea and vomiting were significantly associated with the risk of H. pylori infection for children, and the child having her/his own room was significantly associated with a reduced risk. Income was not associated with H. pylori infection in children and was inversely associated in parents.

CONCLUSION

The prevalence of H. pylori infection in family units of Japanese Brazilians supports the hypothesis of a predominant role for mother-child transmission of H. pylori infection, mainly through contact with regurgitated gastric juice in the mother's mouth.

Peptic ulcer disease associated with Helicobacter felis in a dog owner

The aim of this study was to investigate the identity of the Helicobacter heilmannii-like bacteria found in the stomach of a human patient suffering from stomach ulcers and her asymptomatic pet dog. An elderly woman was referred for gastroscopy because of right hypochondrial pain, nausea, anorexia and vomiting. Gastric ulcers were observed and histology revealed the presence of multiple H. heilmannii-like bacteria. Multiplex polymerase chain reaction (PCR) identified the bacteria as H. felis. Her pet dog was also examined gastroscopically. Only mild gastric lesions were found but PCR showed the presence of H. felis as well as H. bizzozeronii and Candidatus H. heilmannii. This report associates H. felis infection in humans with severe gastric ulceration. Moreover, the suggestion can be made that the patient contracted H. felis from her dog.

Helicobacter pylori infection: further evidence for the role of feco-oral transmission

BACKGROUND

Helicobacter pylori infection is recognized as a major cause of chronic digestive diseases with a major public health impact, yet the knowledge of transmission pathways is limited. We studied the transmission in employees taking care of institutionalized persons with mental disabilities with a documented high prevalence of H. pylori.

MATERIALS AND METHODS

Six hundred and seventy-one health-care workers were screened for H. pylori serology. For each employee, information was collected on age, sex, father's and mother's education level, number of household members and number of children sleeping in the same bedroom during childhood, as well as lifestyle factors such as smoking and tropical journeys and occupational exposure data such as type of contact with inhabitants (changing napkins with stools, washing inhabitants, feeding inhabitants, personal contact) and seniority in the institution.

RESULTS

Seroprevalence for H. pylori increased significantly with age. In univariate analysis, risk factors for H. pylori positivity were (age-adjusted): father's education, mean length of employment, smoking, contact with fecal materials of inhabitants, washing and feeding of inhabitants. Controlling for confounders, in multiple logistic regression analysis, only fecal contact remained as a significant risk factor for H. pylori infection.

CONCLUSIONS

In health-care workers caring for a population with a high prevalence of H. pylori infection, there is an association with fecal transmission. This, however, does not rule out the possibility of other ways of transmission.

Acquisition of Helicobacter pylori infection in rhesus macaques is most consistent with oral-oral transmission

Socially housed rhesus monkeys rapidly acquired Helicobacter pylori infection, although the organism was rarely cultivated from saliva, feces, or the environment. Since the concentrations of H. pylori in vomit were compatible with what is known about the infectious dose, our results are most consistent with an oral-oral means of transmission.

Some fibrocystic breast change may be caused by sexually transmitted H. pylori during oral nipple contact: supporting literature and case report of resolution after gut H. pylori eradication treatment

OBJECTIVES

To briefly review previously published evidence for Helicobacter pylori (Hp), colonization of extra-intestinal sites and suggest an hypothesis that breast acini and ducts be added to this list, concluding such breast colonization is not rare and is a sexually transmitted infection.

METHODS

PubMed literature search and review with a case report.

CONCLUSIONS

(1) Evidence indicates oral Hp is common and can remain in the mouth after successful eradication in stomach and duodenum. (2) Evidence indicates that the breast is also occasionally colonized by Hp. (3) Hp may be injected retrograde up into ducts of the breast during oral nipple stimulation during sexual activity and this Hp may give rise to some cases of fibrocystic breast change. (4) A case of painful fibrocystic change that had been present for two years in a 27 year old female, resolved after gastrointestinal Hp treatment.

Absence of vertical transmission of Helicobacter pylori in an experimental murine model

Helicobacter pylori (H. pylori) infection is acquired mainly in early childhood but the precise transmission routes are unclear. This study examined the maternal H. pylori infection status in order to determine the potential of perinatal transmission. These issues were investigated using an experimental murine model, the Mongolian gerbil, which has been reported to be the most suitable laboratory animal model for studying H. pylori. Pregnant Mongolian gerbils, infected experimentally with H. pylori, were divided into two groups. The stomachs of the mother and litters were isolated and assessed for the transmission of H. pylori at the prenatal period (2 weeks after pregnancy) and at the parturition day. The bacterial culture, polymerase chain reaction (PCR) and rapid urease test were used to examine the presence of the transmitted H. pylori. There was no H. pylori observed in any of the fetuses during pregnancy and in the litters at parturition. This suggests that vertical infection during the prenatal period or delivery procedure is unlikely to be route of mother-tochild transmission of a H. pylori infection.