[Ex-vivo assessment of meningococcal resistance to natural immunity: serum bactericidal assays versus whole- blood assay]

Literature review indicates that antibiotic resistance of bacteria may be associated with the resistance to host natural immunity. In the previous study we found that: all meningococcal isolates of meningitis cases are less sensitive to typical anti-meningococcal antibiotics. In present study, the association of the above characters was analyzed in an ex-vivo "case-control" study. A randomized controlled trial compared effect two dietary treatments [low glycemic index and low fat] in 46 adults, ages 18-55 years old, BMI >27,who proceed to motahary clinic in shiraz, Iran. Body weight, BMI, WHR [waist/hip ratio], fast and post-prandial Plasma lipid profile [Triacylglycerol, total Cholesterol, LDL-C, HDL-C concentration] level of obese women measured at the beginning and at the end 6 weeks. The resistance of both groups against selected sera were similar in the ratio 1:2- by SIC and SBC methods. The growth of "test" and "control" groups in the pooled sera were stopped at the ratios 1:512 and 1:1024 respectively. In SB A the population of "test" and "control" groups decreased in parallel to each other. However, the invasive [test] meningococcal strains established slower reduction in WBA. Studies on the correlation between antibiotic resistance of bacteria and the resistance to the natural immunity have ended with different results. According to our experience, it seems that for ex- vivo investigation of natural immunity against meningococci the WBA is more reliable

Neisseria meningitides carrier rate among military recruits in Kerman, south-east of Iran

Meningococcal diseases have been recognized as an important problem in military population. Most patients with meningococcal diseases have not had a direct contact with other similar patients. Thus, asymptomatic carrier is presumably the major source of transmission of pathogenic strains. To determine the carrier rate of the newly-arrived recruits to a military center and to find out the sensitivity pattern of the isolated strains. One thousand four hundred and fifty-six tonsilopharyngeal samples were collected during a 15-month period from 2002 through 2003. All the samples were plated on chocolate agar supplemented with 3 mg/L vancomycin and 2 mg/L amphotericin B. Meningococci were identified by a standard method. Sero-grouping of part of isolated strains was carried out by the slide agglutination test. The antibiotic resistance was measured by the broth macrodilution method with penicillin, rifampicin, and ciprofloxacin. Sensitivity of part of isolated strains against two antiseptic solutions, chlorhexidine and eucalyptus inhaler, were also tested. The mean of meningococcal carrier rate in 4+1 seasons was 11.4% for the newly arrived recruits. After 1[1/2]- 2 months, it raised to 33%. Increases observed in cold seasons were considerable. During the second sampling stage, the mean carrier rate was 38% for smokers and 28% for nonsmokers. Strains isolated from carriers were phenotypically heterogeneous, with a dominance of group B [tilde27%]. All the invasive strains recovered concurrently from the patients with meningococcal diseases also belonged to this sero-group. The median of minimum inhibitory concentrations [MICs] for penicillin and rifampicin were 0.06 and 0.03 microg/mL, respectively. The MIC[50] of ciprofloxacin was 0.004. Thirteen percent of the isolates were partially resistant to penicillin. It was 8% for rifampicin. More than 60% of the isolated strains were sensitive to 1/600 dilution of chlorhexidine. It was negligible against the eucalyptus inhaler. Our results indicate that the transmission rate is strongly associated with the season. Furthermore, there is a correlation between the carrier state and smoking habit. Domination of B sero-group among the carriers and patients could be due to the lack of B antigen in the available vaccines. The resistance pattern of tested strains was similar to that of other studies