Identification and molecular characterization of mycobacteria isolated from animal sources in a developing country.

The essential role of animals in the transmission of infectious diseases has long been recognized. Apart from zoonosis due to Mycobacterium bovis in domestic cattle, acquired mycobacterial zoonosis from animals are vastly under-reported worldwide. This is partly the result of not recognizing that animals can be the source of zoonotic nontuberculous mycobacteria (NTM) infection. The present study intended to be a contribution to the knowledge of somewhat neglected role of animals in harboring, maintenance and dissemination of NTM in the environment. A total of 326 samples from 250 animals were collected and analyzed for the presence of mycobacteria using standard protocols. The preliminary identification and Runyon's classification of isolates were performed by conventional tests. The PCR amplification of a 228 bp fragment of 65-kDa heat shock protein (hsp) gene was applied for the genus identification and the partial sequence analysis of 16S rRNA was applied for the species identification. In total 32 isolates including 26 rapidly growing and 6 slowly growing mycobacteria were recovered from 250 animal samples (12.8%). The isolates recovered from 21 (65.60%) fish, 8 (25%) insects and 3 (9.4%) house cats, dogs and mice. M. fortuitum was the most frequent Mycobacterium spp (13 isolates; 40.6% of all isolates), followed by M. abscessus-chelonae-M. saopaulense group, (5 isolates; 15.6% of all isolates), M. iranicum (3 isolates; 9.4% of all isolates),and M. marinum, M. terrae complex and M. chlorophenolicum (2 isolates each; 18.8% of all isolates), and the single isolates of M. mucogenicum, M. neoaurum, M. conceptionense, M. virginiense, and M. gordonae (5 isolates; 15.6% of all isolates). The current study indicates that a variety of animals can be a permanent or transient source of mycobacterial agents. This ensures the life cycle of the bacteria and the chance of their survival in the environment, which may pose a potential threat to human health.

Species diversity and molecular characterization of nontuberculous mycobacteria in hospital water system of a developing country, Iran.

BACKGROUND: Hospital environment is of crucial importance in cross-transmission of opportunistic pathogens to the patients. Nontuberculous mycobacteria have the remarkable capability to withstand the adverse condition of hospital environments and pose a potential threat to the health of patients. The current study aimed to assess the frequency and diversity of mycobacteria in hospital water of a developing country using a combination of conventional and molecular methods. METHODS: A total of 148 hospital water samples collected from 38 hospitals were analyzed for the presence of mycobacteria using standard protocols for isolation and characterization of the isolates. The conventional tests were used for preliminary identification and Runyon's classification, the PCR amplification of hsp65 gene and sequence analysis of 16S rRNA were applied for the genus and species identification. RESULTS: A total of 71 [48%] isolates including 30 rapidly growing and 41 slowly growing mycobacteria were recovered. The three most prevalent species were M. lentiflavum, 28.2%, M. paragordonae, 21.1%, and M. fredriksbergense, 9.8%, followed by M. simiae and M. novocastrense, 7%, M. canariasense and M. cookii like, 5.6%, M. setense, 4.2%, M. fortuitum and M. gordonae, 2.8%, and the single isolates of M. austroafricanum, M. massiliense, M. obuense, and M. phocaicum like. CONCLUSION: The results of our study show that the hospital water resources, drinking or non-drinking can be the reservoir of a diverse range of mycobacteria. This reaffirms the fact that these organisms due to intrinsic resistance to common antiseptic and disinfectant solutions persist in hospitals and create a threat to the patient's health and in particular to those that suffer from weakness of immunity.

First report of isolation of Mycobacterium canariasense from hospital water supplies.

Mycobacterium canariasense was first isolated as a novel species in 2004 from clinical specimens in Spain. Since then there have only been a few additional reports from Spain, the USA, and Lebanon on the isolation of this rare species from clinical specimens. We herein present the first report on isolation of this organism from hospital water, which provides evidence for determining the natural habitat of this rare species. The water samples were collected from hospital departments and cultured on Löwenstein-Jensen and Sauton's media. The isolates, i.e. WP5, WP20, and AW2-3, were subjected to identification by conventional and molecular tests including sequencing analysis of 16S rRNA. The water isolates revealed phenotypic and molecular features consistent with M. canariasense including a genus-specific amplicon of the hsp65 gene and 100% similarities with those of M. canariasense CIP: 107998(T) 16S rRNA gene sequences. The current report might be of value in tracing the probable source of infection in patients.

First report of isolation of Mycobacterium novocastrense from water supplies.

We herein present the first documented report associated with the isolation of Mycobacterium novocastrense from environment. The identification and characterization of four unrelated isolates, one from the surface water and the other three from hospital water, were achieved by various conventional and molecular tests including a genus-specific PCR for Mycobacterium based on 65-kDa heat shock protein (hsp) gene and 16S rDNA sequencing. Our findings might shed further light on the natural habitat of this rare Mycobacterium.

Isolation and molecular identification of biodegrading Mycobacteria from water supplies of Iranian hospitals.

BACKGROUND AND OBJECTIVES: Some microorganisms, mainly members of two genera including Pseudomonas and Mycobacterium, were found to be capable of transforming and degrading of polluting agents. We herein report the isolation of a few mycobacteria with the ability to biodegrade organic and inorganic compounds from water supplies of Iranian hospitals. MATERIALS AND METHODS: The water samples were collected from hospital water supplies. Isolation processes were done according to standard methods. The colonies were subcultured on Löwenstein-Jensen medium to obtain a pure culture. The identification and characterization of the isolates were based on conventional and molecular methods including direct sequence analysis of almost full length of 16S rRNA gene. RESULTS: The almost complete 16S rRNA gene sequences of the studied strains revealed that the isolates WP16, AW18-1 and AW18-3 were identified as M. fredriksbergense, AW18-2 as M. austroafricanum, AW27-2 as M. obuenseand AW27-6 as M. phocaicum.The relationship between our isolates and standard strains of Mycobacterium was supported by a phylogenetic tree of 16S rRNA gene. CONCLUSION: In the current study we were able to isolate and characterize six mycobacteria with capability of transforming and degrading polluting agents from Iranian hospital environments. This is indeed the first report on isolation and characterization of mycobacteria with degrading capability of polluting agents from Iranian hospitals. It can be considered as a pioneer study to open up a new horizon in the study of microbial diversity in Iran with an objective-based and applied approach to tackle environmental challenges.

Conventional and molecular investigation of Shigella isolates in relation to an outbreak in the area of Isfahan, Iran.

BACKGROUND AND OBJECTIVE: Over 165 million cases of shigellosis occur in the world each year, mostly in developing countries. Outbreaks of shigellosis are associated with poor sanitation, natural calamities, contaminated food and crowded living conditions. In late summer 2006, during the final stage of an outbreak of shigellosis at a vast region of Isfahan province, Naein & Ardestan, our laboratory was assigned to investigate the outbreak in order to determine the causative agent. MATERIALS AND METHODS: A total of 146 rectal swabs which had been collected from the patients by local laboratories on separate days were screened using a battery of conventional and molecular tests. RESULTS: Thirteen specimens tested positive for Shigella spp. They were identified as S. sonnei (6, 46.1%), S. dysenteriae (4, 30.8%), S. flexneri (2, 15.4%) and Shigella spp (1, 7.7%) by conventional and molecular microbiological tests. According to ribotyping results the isolates were grouped into 3 distinct clusters encompassing the majority of isolates and a single line of descent representing isolate S122 which was nonreactive with any Shigella polyvalent antisera. CONCLUSION: This diarrheal outbreak appeared to be the result of shigellosis. Despite the fact that Shigella sonnei was the predominant organism isolated from patients, the causative agent of outbreak diarrhea remains obscure, since other Shigella species were also involved. The serologic testing supports this conclusion, as do the molecular patterns of the Shigella isolates. Having considered the time of investigation which was in the late stage of the outbreak, it was very likely that a collection of endemic and epidemic clinical samples was screened resulting in isolation of various Shigella species.

Assessment of relationship between active ulcerative colitis and cytomegalovirus infection among Iranian patients.

INTRODUCTION: It has been previously reported that ulcerative colitis (UC) could be associated with cytomegalovirus (CMV) infection. There is controversy among different studies; however, this study is conducted in Isfahan. We evaluated the frequency distribution of CMV infection in Iranian patients with active UC comparison to normal individuals. MATERIALS AND METHODS: This case-control study was conducted on 22 patients with active UC and 22 age- and sex-matched controls (F: M = 1). Samples were taken from colonoscopic specimens and tested with sensitive primers of the CMV using the polymerase chain reaction method, the most sensitive method for detecting CMV infection. RESULTS: Patients and controls were similar in age (35.9 ± 11.03 years in the case and 40.8 ± 11.3 years in the control group) P=0.153. CMV DNA was found in 13.6% of the subjects in each group; therefore, total percentage of CMV infection was 13.6%. Six cases with CMV infection were three males and three females with age of 38.5 ± 11.02 years (compared to 38.3 ± 11.5 years in noninfected subjects P=0.968). CONCLUSION: In our study, Iranian patients with active UC did not have a higher rate of CMV infection than controls.