Increasing trend of metronidazole resistance in the treatment of Helicobacter pylori infection: A global challenge

Helicobacter pylori are gram negative spiral bacteria that colonize the human stomach. Infection with H. pylori is associated with chronic gastritis, peptic ulcer, gastric adenocarcinoma and gastric mucosaassociatedlymphoid tissue (MALT) lymphoma. Antibiotic resistance is an ever increasing problem with the treatment of most microbial infections including H. pylori; and has become a growing problem worldwide with the eradication of this organism. In recent years, several treatment regimens have been proposed for H. pylori eradication. However, the only conditions for which such treatment is strongly recommended on the basis of unequivocal supporting evidence are peptic ulcer disease and low gradegastric MALT lymphoma. Success of antimicrobial regimens for H. pylori eradication depends on patient compliance and lack of antimicrobial resistance. Metronidazole (Mtz) containing regimens have been shown to limit effectiveness because of increasing prevalence of resistance to this drug. A high prevalence (> 90%) of Mtz resistance in H. pylori has been reported especially in developing countries. Mtz resistance may be mediated through an inability of Mtz-resistant strains to remove oxygen from the site of Mtz reduction, thereby preventing Mtz activation. This has been attributed to a mutation on the frxA and/or rdxA genes resulting in strains of the organism with defective nitro-reductases coded bythese genes. Infection by Mtz or amoxicillin resistant strains is an important factor leading to treatment failure; subjecting all H. pylori clinical isolates to susceptibility testing most especially to Mtz is recommended. If not possible, a program to survey the prevalence of resistance should beimplemented in a given area or population. This increasing emergence of antimicrobial resistance in H.pylori treatment posses serious public health problems and is therefore necessary that new drug regimens be examined

Helicobacter pylori infection and transmission in Africa: Household hygiene and water sources are plausible factors exacerbating spread

Helicobacter pylori (H. pylori) is a microaerophilic motile curve rod that inhabits the gastric mucosa of the human stomach. The organism chronically infects billions of people worldwide and is one of themost genetically diverse of bacterial species. Infection with the bacterium which leads to chronic gastritis, peptic ulceration, gastric cancers and gastric malt lymphoma has been reported to follow a pattern linked to geographic and socio-demographic factors. Studies have documented a higherprevalence in Africa than elsewhere although the pathological outcomes do not correlate with infection. H. pylori transmission pathways are still vague, but the risks of transmission include precarious hygiene standards, over-crowding and contaminated environment and water sources amongst others. The possible routes of transmission include oral-oral, faecal-oral and person- to -person, either with or without transitional transmission steps during episodes of diarrhoea or gastro-oral contact in the eventof vomiting. Use of contaminated water including municipal tap water has also been suspected to have a high impact in the transmission of the organism. To generate the data presented in this paper, we conducted an internet based search on relevant literature pertaining to H. pylori epidemiology in general and Africa in particular. Sites such as Pubmed, AJOL, Scopus and Goggle scholar were mainly used. This paper therefore attempts to appraise the role of household hygiene and water sources in the transmission of this organism in the developing world context

49 Marked susceptibility of South African Helicobacter pylori strains to ciprofloxacin and amoxicillin: Clinical implications

Objectives. Helicobacter pylori-associated infection is commonin South Africa, as in other developing countries. Antibioticresistance is recognised as a major cause of treatment failure.We studied the susceptibility and resistance patterns of H.pylori to guide empiric treatment and prevent the emergenceof resistance.Methods. Two hundred H. pylori strains obtained from gastricbiopsies of patients presenting with gastric-related morbiditiesattending Livingstone Hospital, Port Elizabeth, were evaluatedfor their susceptibility to seven antibiotics – metronidazole,clarithromycin, tetracycline, amoxicillin, gentamicin, ciprofloxacin and erythromycin. H. pylori was isolated following standard microbiology procedures, and susceptibility determined using the Kirby-Bauer disc diffusion and agar dilution methods. Comparisons of antimicrobial resistance rates with sex of the patients were determined using the chisquare test; a p-value o

Helicobacter pylori prevalence in dyspeptic patients in the Eastern Cape province – race and disease status

Objectives. We examined Helicobacter pylori infection in patients with gastric-related morbidities at Livingstone Hospital, Port Elizabeth, to determine the prevalence and risk factors for infection according to race, endoscopic diagnosis, age and sex. Methods. Gastric biopsies were collected from 254 consecutive patients and H. pylori was isolated on Columbia agar base supplemented with 7% sheep’s blood and Skirrow’s supplement containing trimethoprim (2.5 mg), vancomycin (5 mg) and cefsulodin (2.5 mg). Amphotericin (2.5 mg) was added to the medium. Recovered isolates were identified following standard microbiology and biochemical techniques. Presumptive isolates were further confirmed by polymerase chain reaction (PCR) targeting the glmM gene. Fisher’s exact test was used to assess the univariate association between H. pylori infection and the possible risk factors. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated to measure the strength of association, using EPI INFO 3.41 software. p-value

In vitro anti-Helicobacter pylori activity of Lycopodium cernuum (Linn) Pic. Serm

Helicobacter pylori, a gram negative microaerophilic bacterium is a major etiological agent in duodenal, peptic and gastric ulcers. In this study, gastric biopsy samples were obtained from patients presentingwith gastroduodenal complications. H. pylori was isolated from the specimens following standard microbiology procedures, and isolates subjected to pure fractions of Lycopodium cernuum extracts forantimicrobial assays. Extracts were fractionated by partition chromatography with solvents of increasing polarity to obtain pure fractions. The disk diffusion method was used to determine thesusceptibility of 15 strains of H. pylori to the fractions. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for the most active fraction was also determined by thebroth dilution method. Results were analyzed by the Fisher’s exact test. All the fractions tested demonstrated antimicrobial activity with zone diameters of inhibition between 0 - 30 mm. Of the 5 fractions obtained, the hexane (Hex) fraction was the most active. The lowest MIC and MBC recorded for the hexane (Hex) fraction were 0.016 and 0.125 mg/mL, respectively. There was no statistically significant difference (P>0.05) in the potency of the fraction on the different bacterial strains tested, both for the MIC and MBC. It is concluded that this plant may contain compounds with therapeutic activity, which may be found in the Hex fraction (100%)

Trends in upper gastrointestinal diagnosis over four decades in Lusaka, Zambia: a retrospective analysis of endoscopic findings

BACKGROUND AND AIMS: There a shortage of robust information about profiles of gastrointestinal disease in sub-Saharan Africa. The endoscopy unit of the University Teaching Hospital in Lusaka has been running without interruption since 1977 and this 38-year record is largely intact. We report an analysis of endoscopic findings over this period. METHODS: Written endoscopy records from 29th September 1977 to 16th December 2014 were recovered, computerised, coded by two experienced endoscopists and analysed. Temporal trends were analysed using tables, graphs, and unconditional logistic regression, with age, sex of patient, decade, and endoscopist as independent variables to adjust for inter-observer variation. RESULTS: Sixteen thousand nine hundred fifty-three records were identified and analysed. Diagnosis of gastric ulcer rose by 22 %, and that of duodenal ulcer fell by 14 % per decade. Endoscopically diagnosed oesophageal cancer increased by 32 % per decade, but gastric cancer rose only in patients under 60 years of age (21 % per decade). Oesophageal varices were the commonest finding in patients presenting with haematemesis, increasing by 14 % per decade in that patient group. Two HIV-related diagnoses, oesophageal candidiasis and Kaposi’s sarcoma, rose from almost zero to very high levels in the 1990s but fell substantially after 2005 when anti-retroviral therapy became widely available. CONCLUSIONS: This useful dataset suggests that there are important trends in some endoscopic findings over four decades. These trends are not explained by inter-observer variation. Reasons for the divergent trends in incidence of peptic ulceration and apparent trends in diagnosis of upper gastrointestinal cancers merit further exploration

Helicobacter pylori infection in Africa: Pathology and microbiological diagnosis

Helicobacter pylori is a microaerophilic motile curve rod that inhabits the gastric mucosa of the human stomach. The organism chronically infects billions of people worldwide and is one of the most genetically diverse of bacterial species. Infection with the bacterium which leads to chronic gastritis, peptic ulceration, gastric cancers and gastric MALT lymphoma has been reported to follow a pattern linked to geographic and socio-demographic factors. However; the infection rate in various populations does not parallel the incidence of morbidity caused by the infection. This has been termed by a number of authors as the ‘African enigma’ based on an apparently low incidence of gastric carcinoma and other H. pylori-associated morbidities in the continent of Africa. There are various techniques employed to detect H. pylori from specimens. These tests may be invasive or non-invasive. Endoscopy and gastricmucosal biopsy, microscopic examination of histological sections, PCR and rapid urease test are forms of invasive test that could be used. Non-invasive tests such as Urea Breath Test (UBT) make use of theability of the organism to produce urease; enzyme linked immunosorbent Assay (ELISA), H. pylori stool antigen test, and latex agglutination tests are important non-invasive serological approaches employed to detect the presence of antibody or antigen from a specimen. H. pylori is a very fastidious bacterium. Restraint should therefore be exercised to allow for efficient performance of some of these techniques