Clinical presentation in relation to diversity within the Helicobacter pylori cag pathogenicity island

OBJECTIVE: This study investigated the genetic diversity of the cag pathogenicity island (PAI) in Helicobacter pylori (H. pylori) in relation to clinical outcome and interleukin (IL)-8 production. METHODS: Seven genes in the cag PAI (cagA, cagE, cagG, cagM, cagT, open reading frame 13 and 10) were examined by polymerase chain reaction and Southern blot hybridization using H. pylori from 120 patients with different presentations (duodenal ulcer, gastric cancer, gastritis alone). IL-8 production from AGS cells (gastric cancer cell line) cocultured with H. pylori was measured by ELISA. RESULTS: An intact cag PAI was present in 104 (87%) isolates, and five (4%) had deletions within the cag PAI; 11 (9%) lacked the entire cag PAI. Clinical isolates containing the complete cag PAI induced a greater secretion of IL-8 as compared with those without the cag PAI (3048 +/- 263 vs 480 +/- 28 pg/ml, p < 0.001). Deletion of only cagG reduced IL-8 secretion by two thirds. Deletions of more than one locus reduced IL-8 secretion to background. A similar proportion of H. pylori from patients with gastritis, duodenal ulcer, or gastric cancer had intact cag PAI (88%, 88%, and 85%, respectively). Although the presence of cagG was a better predictor of the presence of an intact cag PAI than cagA or cagE, the presence or absence of any of these genes had no association with clinical presentation. CONCLUSION: Although the cag PAI plays an important role in IL-8 production, clinical presentation cannot be predicted by the presence of an intact cag PAI or any of these seven cag PAI genes.     

Sensitivity of Amoxicillin-Resistant Helicobacter pylori to Other Penicillins

The sensitivities to penicillins and to a penicillin and beta-lactamase inhibitor combination agent were determined for Helicobacter pylori strains that were sensitive, moderately resistant, or highly resistant to amoxicillin. All strains were resistant to nafcillin and oxacillin. Moderately resistant strains showed an intermediate zone of inhibition to ticarcillin, mezlocillin, piperacillin, and amoxicillin-clavulanic acid. High-level resistance was associated with the smallest zone size for all penicillins tested.     

Helicobacter pylori infection in Kazakhstan: effect of water source and household hygiene

The epidemiology of Helicobacter pylori infection and risk factors associated with its transmission are not well understood. Kazakhstan is country with two ethnic groups, Asian (Kazakhs) and Western (Russians), living under similar socioeconomic conditions. The aim of this study was to examine the seroepidemiologic pattern of H. pylori and hepatitis A among the same individuals from both ethnic groups, with emphasis on water source and household sanitation practices. This was a cross-sectional seroepidemiologic study conducted among unrelated healthy individuals in Kazakhstan. From May through August 1999, individuals between the ages of 10 and 60 years from Almaty, Kazakhstan, were invited to participate. Demographic information, socioeconomic factors, living conditions, and various aspects of the local household environment including access to water were collected. A clean water index (CWI) was created based on combined factors, consistency of boiling water before drinking, frequency of storing and reusing water, and frequency of bathing and showering. H. pylori and hepatitis A antibodies were assessed by enzyme-linked immunosorbent assay. Two hundred eighty-eight individuals between the ages of 10 and 60 years participated. The prevalence of H. pylori infection was almost identical among the two ethnic groups (Russians 79% and Kazakhs 80%). H. pylori infection was inversely correlated with the CWI (i.e., 56%, 79%, and 95% for high, middle, and low, respectively (P < .05). Drinking river water had highest risk of H. pylori infection (OR = 13.6, 95% CI = 1.8-102.4; P < .01, compared with tap water). Crowding showed no significant effect on H. pylori prevalence. Anti-HAV antibodies were found in 86% of the population, 90% among the Russians versus 82% among the Kazakhs (OR = 1.8, 95% CI = 1.1-3.8, P = .05). Although the two infections were highly correlated (P < .001), antibody to both infections were present simultaneously in only 74%. The prevalence of H. pylori infection in Kazakhstan is very high. The data suggest that transmission of H. pylori can be water borne, related to poor sanitary practices, or both. The high prevalence of antibodies to H. pylori and HAV among this population is a marker for poor sanitation and hygienic practices. Reducing the rate of H. pylori transmission will require improvements in overall sanitation including clean water, waste disposal, as well as in household hygienic practices.     

Tobramycin in ophthalmology

Selman Waksman's laboratory at Rutgers University discovered the first aminoglycoside antibiotic, streptomycin, in 1943. Other aminoglycoside antibiotics, such as gentamicin and tobramycin, soon followed. Tobramycin is compatible with most intravenous fluids and tear substitutes, but it is incompatible with heparin and some beta-lactam antibiotics such as penicillin and cephalosporins. Due to tobramycin's broad spectrum of activity, it has proven useful in controlling both superficial and deep infections of the eye and ocular adnexa (i.e., blepharitis, conjunctivitis, keratitis, and endophthalmitis). However, since tobramycin has been associated with neuromuscular blockade, as well as possessing ototoxic and nephrotoxic effects, care must be taken to minimize toxicity by monitoring patients undergoing systemic tobramycin therapy.     

In vitro susceptibilities of ocular Bacillus cereus isolates to clindamycin, gentamicin, and vancomycin alone or in combination.

A broth dilution assay was used to determine the in vitro susceptibilities of 10 ocular isolates of Bacillus cereus to clindamycin, gentamicin, and vancomycin both alone and in combination. The checkerboard technique was used to determine fractional inhibitory and bactericidal concentration indices for combinations of clindamycin-gentamicin and vancomycin-gentamicin.     

Prevalence of a human retrovirus in native Japanese: evidence for a possible ancient origin

The origin of a human retrovirus (ATLV or HTLV-I) is, at present, unknown although carriers of the virus have been found in Japan, the Caribbean basin and Africa. By means of a sero-epidemiological study, the Ainu people of Hokkaido, located in the northernmost island of Japan, were shown to have antibody to the virus in high frequency. Since the Ainu are regarded as descendants of the pre-agriculture native population of northern Japan, this finding appears to indicate that the retrovirus was already present in the aboriginal Japanese of prehistoric times.