Iranian Journal of Microbiology
Volume:6 Issue: 4, Aug 2014

The high prevalence of resistance to penicillin by Streptococcus pneumoniaeis considered as a great concern, particularly in Asian countries. The aim of this study was to investigate the changing trend of penicillin-resistant S. pneumoniae (PRSP) in Asia over a 20 years period.A review of the literature was conducted using the PubMed database, Google Scholar, Scopus, two Persian scientific search engines “Scientific Information Database” (www.sid.ir), and “Mag Iran” (www.magiran.com) through 1993 to 2013. Our study provides a unique chance to investigate the changing trend in PSSP in Asia over a 20 years period. Susceptibility rates among different centers in each country varied widely. In Malaysia, the PSSP rate decreased from 97.2% in 1995-1996 to 69% in 2000. In Singapore, PSSP levels decreased from 72.6% in 1997 to 30.5% in 2007-2008. In Iran, PSSP ranged from 0% to 100%. In Taiwan, the rate of PSSP was 60.3% in 1995 and <50% in other years. In Lebanon, the rate of PSSP was less than 50% (ranging from 30.1% to 50%) in all published data. In Hong Kong, the level of penicillin susceptibility decreased from 71.1% during 1993-1995 to less 42% in 2007.Continuous surveillance of resistance data from clinical isolates as well as implementation of strict infection control policies is recommended. More studies are needed for better evaluation PSSP rate in some Asian countries such as Vietnam, Singapore, Philippines, Pakistan, Nepal, Kuwait, Korea and Indonesia.

Bacterial meningitis is one of the most serious infections and should be treated as emergency. As it has significant morbidity and mortality throughout the world, every country should have precise information regarding the etiological agents of disease and populations at risk to design public health prevention strategy. In the present study in addition of evaluation of common etiological agents (Haemophilusinfluenzae, Neisseria meningitidis, and Streptococcus pneumoniae) in bacterial meningitis cases, we sero-grouped or serotyped the obtained agents in order to predict the usefulness of existing vaccines against bacterial meningitis.Materials and Cerebrospinal fluid of 182 suspected meningitis patients were collected, from which 114 cases were approved by biochemical, microbiological and molecular tests as bacterial meningitis. The isolated bacteria were serogrouped or serotyped to determine the dominant serotypes.Streptococcus pneumoniaeaccounted for 36%,Haemophilus influenza for 26%and Neisseria meningitidisfor 14% of cases. From 13 serogroups of N. meningitides, the most frequent serogroups, were meningococcus group B (51%), C(24%) A (18%), Z(2%), W135 (1%) and 3% was not identified. In H. influenzae group only serotype b (100%) have been identified and in pneumococcal meningitis the most common serotype among our cases were 18C (44%) followed by14 (17%), 19A(13%), 6A (9%),7F (4%),4(3%), 3 (3%), 9V (2%), 8 (2%),23f (2%), 5(1%). Since there is no nationwide mass immunization program for common agents of bacterial meningitis in Iran, the result of this study can be used to improve the existing vaccines to cover the detected serotypes and consequently reduce the incidence of bacterial meningitis.

Mycoplasma hominis and Ureaplasmaurealyticum are important opportunistic pathogens that cause urogenital infections and accelerated newborn delivery in pregnant women. Moreover genital mycoplasmas have been implicated in different neonatal diseases such as pneumonia, sepsis and meningitis. This study was conducted to find out the prevalence and transmission rate of these two organisms in pregnant women and their neonates. Nasotracheal and pharyngeal specimens of 165 newborns hospitalized at Neonatal Intensive Care Unit (NICU) of RasoulAkram Hospital (during 2010 – 2011) were assessed by PCR to detect M. hominis and U. urealyticum. Moreover, PCR of vaginal specimens from their mothers were obtained to determine the prevalence of these organisms in pregnant women and rate of transmission to their newborns. data were analyzed using SPSS software. Totally, the results of PCR were positive in 33 newborns (20%). Vaginal colonization among the mothers was found to be 15% (25/165) for U. urealyticum and 15% (25/165) for M. hominis. The transmission rate to their infants was 72% and 60% for U. urealyticumand M. hominis, respectively. These data indicate that vertical transmission of mycoplasma and ureaplasma are prevalent in newborns. Since these organisms cause serious infections in neonates, it would be better to perform screening tests in pregnant women before the delivery in order to prevent transmission to neonates and consequent infections and morbidities amongthem.

Shigellosis is an acute gastroenteritis that is one of the most common causes of morbidity and mortality in children with diarrhea in developing countries. The purpose of this study was to describe the distribution of Shigellaserogroups and serotypes and their antibacterial drug resistance profiles.fecal samples of all children suffering from shigellosis who had been admitted to Abuzar Children’s Hospital in Ahvaz, southwestern Iran, from September 2008 to August 2010 were examined. Antibiotics susceptibility testing was performed according to the Kirby Bauer disk diffusion method.Shigellaflexneriwas the predominant serogroup and being identified in 87 isolates (49.8%). The most common S. flexneriserotypes were type 2 (57.56%) and type 1 (21.87%). High rates of resistance were observed to trimethoprime-sulfamethpxazole (85%) and ampicillin (87.5%).S. flexneri and its serotypes was the most frequently isolated Shigella species from southwest of Iran, Ahvaz. Identification of predominant S. flexneriserotypes in developing countries can help in prioritizing strategies such as development of effective vaccines.

Nanoscopic life forms called Nanobacteria or calcifying nanoparticles (CNP) are unconventional agents. These novel organisms are very small (0.1 to 0.5 microns) and possess unusual properties such as high resistance to heat and routine antimicrobial agents. Nanobacteria are 100 times smaller than bacteria and protected by a shell of apatite, so they could be as candidate for emerging and progress of in vivo pathological calcification. In this study, the inhibitory effect of broad-spectrum antibiotics on growth of these new forms of life has been investigated. Powdered urinary and kidney stones were demineralized with HCl and neutralized with appropriate buffers and became filtered. Finally suspension was incubated in DMEM medium with Fetal Bovine Serum (FBS) and broad-spectrum antibiotics (100U/ml for penicillin and 100µg/ml for streptomycin) for 60 days. In the presence of broad-spectrum antibiotics, Scanning electron micrographs (SEM) showed a spherical shape of these nanobacteria. Also, Energy Dispersive X-ray spectroscopy (EDS) showed a pick for calcium and phosphor. Transmission Electron Microscopy (TEM) results illustrated cover around the nanobacteria. The growth of calcifying nanoparticles after adding the broad-spectrum antibiotics may be due to their apatite hard shells supporting them against penetration of the antibiotics.

Fish mycobacteriosis is caused by the non-tuberculous mycobacteria. Infected fish are normally the primary source of infection, although non-tuberculous Mycobacteria can be found in the environment. The present study was designed to investigate the few recently found suspected cases of mycobacteriosis in Iranian ornamental fish tanks. Pathological specimens including granolumas from autopsied fish were used to inoculate Lowenstein-Jensen medium. Genomic material was extracted from all acid-fast positive cultures. The mycobacterial identity of bacterial isolates was authenticated using a PCR assessment targeting a 543 bp-long stretch of 16Sr RNA gene. Further more, a PCR assessment targeting a 294 bp-long stretch of heat shock protein hsp65 was performed and the amplicons were sequenced to identify the isolates. Characteristic mycobacterial bacilli were identified both in light and fluorescent microscopy of bacterial culture from all the suspected specimens. PCR-amplification of DNA templates from all isolates successfully resulted in production of the expected products. Existence of Mycobacterium fortuitum wasconfirmed by comparison analysis of nucleotide sequencing at hsp65 gene. The present work clearly shows mycobacteria are important in pathology of ornamental fish diseases. People who are keeping fish as pet in their homes should be cantioned about the bacterial contamination risks arise from close contact with exotic ornamental species of fish.

Molecular isolation of biodegradable mycobacteriafrom water supplies of Iranian hospitals 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. 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. 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, AW27-2as 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. 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.

To investigate coagulase gene polymorphisms of MRSA and MSSA isolates from Shiraz teaching hospitals from 2011 to 2012. A total of 302 isolates of Staphylococcus aureus were collected from clinical specimens in three major teaching hospitals andconfirmed on the basis of morphological characteristics and biochemical tests. The isolates were subjected to molecular typing on the basis of coagulase enzyme gene polymorphism by PCR-RFLP. There were 27 and 28 different RFLP patterns for AluI and HaeIII restriction enzymes respectively. This study showed that the discriminatory power of coagulase gene typing by Hae III enzyme was more than that of Alu I enzyme. PCR-RFLP method is rapid, reproducible, simple and efficient for typing Staphylococcus aureus isolated from clinical specimens. This study showed that Hae III discriminatory power is better than AluI for typing Staphylococcus aureus isolates.

The genus Malasezia currently includes fourteen species that have been isolated from healthy and diseased human and animal skin. However, there were differences with respect to the species most commonly isolated, not only in patients with various skin diseases but also between healthy individuals.The aim of this study was to analyze the prevalence of Malasseziaspecies from clinically normal skin of the scalp and trunk of healthy individuals and to examine if the range of species varies according to body site, gender and age. The study was conducted at the Department of Dermatovenerology, University Clinical Center in Sarajevo, Bosnia and Herzegovina from December 2012 to May 2013. One hundred healthy men and women with no skin diseases and aged from <1 to 82 years were studied. The samples were obtained by scraping the skin surface from the upper and middle part of trunk and from scalps of all subjects and then incubated on modified Dixon agar. The yeasts isolated were identified by their morphological and physiological properties according to Guillotet al. method. M. sympodialiswas the predominant species on trunk skin in older subjects, M. restricta on scalp skin in age groups 21-35 years, while M. globosa was identified as common species in adults (36-50 years), both from scalp skin and trunk skin. From the trunk skin M. furfur was the most frequent in children. This study confirmed that cutaneous Malasseziamicrobiota in healthy subjects varies by body part and age but not by gender.

Long-term usage of fixed and removable orthodontic appliances creates a favorable environment for the augmentation of oral normal microflora particularly Candida species, which can increases the risk of periodontal lesions. The aim of this study was to assess quantitative and qualitative alterations in the carrier rate of Candida spp. after placement of fixed and removable orthodontic appliances on permanent dentition. Patients enrolled in this study were children aged 7-18 years, who having fixed or removable orthodontic appliances, attended in orthodontics clinic for periodical provision. Six months after beginning of their orthodontic therapy, saliva samples were collected and cultured on Sabouraud dextrose agar for identification and enumerating of isolated Candida colonies. Candida species were identified using the germ tube test and API 20C AUX identification system. Data was analyzed with T-test and Chi square using SPSS 17 software. The average number of Candida colonies isolated from saliva in patients with fixed orthodontic was more than patients with removable appliance (P=0.001). Also frequency of non-albicansCandida species was higher in patients with fixed orthodontic appliances in compare with fixed group (p=0.001). The results suggest that fixed orthodontic appliances treatment promotes an increase in salivary Candida carriers particularly non-albicansCandida species in compare with removable ones. This can indicate a more cautious approach when providing fixed orthodontic treatments for immunocompromised children regarding the increased possibility of candidal infection.

Recently, use of herbal medicine and plant extracts as a substitute for commercially available chemical drugs for control of infectious diseases such as dental caries and periodontal disease has become increasingly popular. The present study was aimed to evaluate the effect of Rhuscoriaria L. water extract on five common oral bacteria and bacterial biofilm formation on orthodontic wire. For primary assessment of the antibacterial properties of Rhuscoriaria L. water extract, the well-plate method in BHIA (Brain Heart Infusion Agar, Merck, Germany) medium was used. Using macrodilution method, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract against each microorganism were determined. The effect of Rhuscoriaria L. on bacterial biofilm formation on orthodontic wire was assessed using viable cell count in biofilm medium (BM) containing 3% sucrose. In the final phase, after fixation of samples in alcohol and glutaraldehyde, samples were prepared for SEM (Scanning Electron Microscopy) analysis. The diameter of the zone of growth inhibition was proportionate to the tested concentrations of the extract. The lowest MIC (0.390 mg/ml) and MBC (1.5 mg/ml) of the Rhuscoriaria L. were found to be against Streptococcus sobrinusATCC 27607. Rhuscoriaria L. water extract decreased bacterial biofilm formation on orthodontic wire at MIC and 1/8 of MIC by S. sanguinis ATCC 10556, S. sobrinusATCC 27607, S. salivarius ATCC 9222, S. mutans ATCC 35608 and E. faecalis CIP 55142 by24.2%-43%, 68.5%-91.6%, 10.6%-79.1%, 22.2%-86.1% and 40.6%-76.4%, respectively. Based on the results, Rhuscoriaria L. water extract had significant antibacterial properties against five common oral bacteria and was able to inhibit bacterial biofilm formation on orthodontic wire. Further investigations are recommended for widespread clinical use of this extract.

A diverse group of Escherichia coli are known as enterohemorrhagicEscherichia coli (EHEC) including O157:H7 and non-O157EHEC. Enterohemorrhagic strains are related to severe clinical conditions in humans including hemorrhagic colitis and hemolytic uremic syndrome, and most of the recorded outbreaks occurred due to O157: H7 E. coli. The aim of the present study was to investigate the presence of O157:H7 E. coli among healthy cattle in Golestan province. Fecal samples were collected from 180 clinically healthy cattle in Golestan province. After primary enrichment, samples were streaked on sorbitol MacConkey agar supplemented with cefixime and potassium tellurite (CT-SMAC). Non-sorbitol fermenting (NSF) Escherichia coli isolates were subjected to serotyping using commercial O157 antisera and rfb O157 gene PCR. Isolates were additionally tested for major virulence factors of EHEC including stx1, stx2,eae and ehlyby multiplex-PCR. Eighteen NSF isolates were recovered from CT-SMAC confirmed as E. coli in biochemical tests. None of the obtained isolates belonged to O157 serogroup. Overall, two isolates harbored the tested virulence genes; one isolate possessed stx2 and ehly, and the other one carried stx2, eaeand ehly. The results of this study indicated that cattle in Golestan province could be the reservoir for non-O157 EHEC.

Contamination of cell lines and biological products is one of the major problems of cell culture techniques. Rapid detection of mycoplasma contamination in cell culture is an important part of quality control standards in related laboratories. The aim of this study was to evaluate the efficacy of PCR in detection of myroplasma as contaminants in cell cultures and other biological products. PCR assays were optimized for 16 S rRNA target gene. Also the utilized PCR method was evaluated in terms of sensitivity and specificity. Finally, a simple DNA extraction and PCR analysis of 164 cell culture of adipose tissue derived mesenchymal stem cells were performed. A 715 bp product was amplified and subsequently was confirmed by sequencing. The technique could detect 10 copies of the target DNA. No cross-reactivity with genomic DNA of other microorganisms was observed. The PCR technique in this study was based on 16S rRNA gene. It was highly sensitive and specific since it was able to detected Mycoplasma contamination in cell cultures

Azotobacter is a diazotroph bacterium reported to possess various plant growth-promoting characteristics. The aim of this study was to isolate Azotobacter strains capable of fixing nitrogen and effectively hydrolyzing both organic and inorganic Pi compounds. In this study, soil samples collected from a diverse range of slightly alkaline soil types were screened for Azotobacter isolates. The inorganic and organic phosphate solubilization potentials of twenty competent phosphate solubilizing Azotobacter isolates were assessed. Variations were noted in the solubilization potentials. Three isolates, identified as Azotobactervinelandii strains O2, O4 and O6, were able to fix atmospheric N2 effectively. The nitrogenase activity of these isolates ranged between 158.6 and 326.4 C2H4h-1vial-1 (ethylene). Bacterial growth rates and phosphate solubilization activities were measured quantitatively under various environmental conditions. A close association was evident between phosphate solubilizing ability and growth rate as an indicator of active metabolism. All three phosphate solubilizing bacteria (PSB) were able to withstand temperature as high as 45°C, high concentration of NaCl (upto 5%) and a wide range of initial pH from 5 to 10 while hydrolyzing phosphate compounds actively.Azotobactervinelandii strains O2, O4 and O6 are superior candidates for biofertilizers that may result in the reduction of chemical nitrogen and phosphate fertilizers leading to increase crop production.

Phytoplanktons are organisms with a very high diversities and global distribution in different habitats. The high distribution of phytoplankton is due to ecological flexibility and their ability to tolerate different climatic conditions and environmental stress.Phytoplankton is the most sensitive biological indicators of water resources. The purpose of this study was to identify the phytoplankton species with emphasis on DNA bar-coding method. The study of phytoplankton variation and the identification of their species composition can provide useful information about the water quality. In this research project, a clone library of the ribosomal small subunit RNA gene (18S rDNA) in the nuclear genome was constructed by PCR using A and SSU-inR1 primers, and then, after examining the clones, selected clones were sequenced. Eleven analyzed sequences were identified correctly and characterized by a similarity search of the GenBank database using BLAST (NCBI). In this study, we revealed a wide range of taxonomic groups in the Alveolata (Ciliphora and Dinophyceae), Stramenopiles (Bacillariophyta and Bicosoecida), Rhodophyta and Haptophyceae. Moreover, we found species of fungi and Metazoa (Arthropoda). Most of the sequences were previously unknown but could still be assigned to important marine phyla. Clone library of 18S rDNA is an accurate method to identify marine specimens and it is recommended as an efficient method for phylogenic studies in marine environments. There seems to be a high diversity and abundance of small eukaryotes in the marine regions of Persian Gulf.