Evaluation of relationship between toothbrush keeping place and its microbial content

Introduction: Maintaining good oral hygiene is an important factor in health. Toothbrushes are commonly used to maintain oral health and prevent dental disease, but unfortunately how keeping the toothbrush is neglected. The aim of this study was to investigate the relationship between toothbrush keeping method and its microbial content. Methods: In this cross-sectional study, 60 volunteers were enrolled and divided into 3 groups based on the places of keeping their toothbrushes (bedroom, bathroom and lavatory). The participants were asked to brush once a day for one month using the first toothbrush which had been delivered; then the first toothbrushes were gathered and a second toothbrush was delivered. The participants were asked to brush once a day using the second toothbrush for 3 months. All toothbrushes were sent for culture and evaluation. All toothbrushes were evaluated by a blind microbiologist. Toothbrush bristles were washed in BHI broth medium; then the resulting liquid was cultured in MacConkey’s agar for gram-negative bacteria and in blood agar and chocolate agar for gram-positive bacteria. Colony counts of Streptococcus mutans, Candida albicans, Pseudomonas, Klebsiella, S. aureus, and E. coli were determined and multiplied by one thousand. Data were analyzed by SPSS version 18 and using Kruskal-Wallis test. Results: At the end of the study the results showed statistically significant differences in microbial load between the groups (p=0.014). Toothbrushes that were kept in bathroom had highest microbial load. Conclusions: Toothbrushes kept in the bathroom had the greatest microbial contamination after three months. According to the results of this study, bathroom is the worst place and bedroom is the best place for keeping toothbrushes

Cytochrome CYP141: A new target for direct detection of Mycobacterium tuberculosis from clinical specimens

Cytochrome P450 CYP141 is an intermediary metabolic and respiratory protein that interferes with oxidation reduction in Mycobacterium tuberculosis. This conserved protein has also been debated as a hypothetical target for therapeutics. We used the sequences of CYP141 gene to develop a PCR for rapid detection of Mycobacterium tuberculosis from respiratory specimens. The sensitivity of this PCR for culture positive-smear positive and culture positive-smear negative samples were 92% and 62.5%, respectively. The overall sensitivity and specificity of this PCR was 85.7% and 97.8%. As compared with other studies, it appears that the CYP141 gene is a good target for direct detection of M. tuberculosis from respiratory specimens

MIRU-VNTR analysis of the Mycobacterium tuberculosis isolates from three provinces of Iran

Background: Iran borders 2 high-burden tuberculosis (TB) countries to the east, and has the highest rates of TB in one of its eastern provinces. Limited information is available on the genetic diversity and transmission dynamics of Mycobacterium tuberculosis (MTB) in Iran. To examine the genetic diversity and transmission dynamics of MTB strains we genotyped a collection of isolates from different parts of Iran. Methods: Standard 15-locus variable number tandem repeat (VNTR) typing was applied to genotype 121 MTB clinical isolates collected from 3 provinces of Iran, including Tehran (the capital of Iran), Sistan-Baluchestan (southeast province of Iran, with the highest rate of TB), and Kermanshah (western part of Iran with high TB/human immunodeficiency virus cases). Antibiotic susceptibility for all isolates was determined using the proportion method. Results: Sixty-six distinct mycobacterial interspersed repetitive unit (MIRU)-VNTR patterns were detected among 121 isolates. Seventy-five strains grouped into 20 clusters, and 46 isolates were unique. The genetic diversity of strains from Sistan-Baluchestan was higher than that in the other provinces. All isolates from Tehran or Kermanshah that grouped into clusters shared identical patterns with Sistan-Baluchestan. The Hunter-Gaston discriminatory index (HGDI) was 0.972, indicating a high power of discrimination for MIRU-VNTR typing. The MIRU 16 and ETRA loci were designated as highly discriminative. The rates of monoresistance and multidrug resistance were 9.9% and 2.4%, respectively. Conclusions: MIRU-VNTR typing revealed high genetic diversity and suggests the possibility of transmission from Sistan-Baluchestan to other provinces of Iran. This method has potential for genetic analysis and for studying the transmission routes of TB