International Journal of Molecular and Clinical Microbiology
Volume:4 Issue: 2, Summer and Autumn 2014

Vulvovaginal candidiasis (VVC) is a common disease among women worldwide, therefore, accurate and rapid diagnosis of causative agents based on molecular techniques utilizing amplification of target DNA is highly recomendad for epidemiological purposes and for effective treatment. The aim of this study was to identify clinically Candida species from VVC patients by restriction fragment length polymorphism (PCR-RFLP). A total of 155 patients with suspicious symptoms of VVC were screened. Candida strains isolated from specimens initially were identified by phenotypic methods and confirmed by molecular approaches based on PCR-RFLP. Fifty one (34%) strains of Candida were obtained from specimens collected from VVC patients. C. albicans was the most frequently isolated species (86.2%) followed by non-albicans, including C. glabrata (7.9%), C. kefir (3.9%), and C. tropicalis (1.9%). The restriction patterns of each Candida species were perfectly specific. The identification of Candida species in VVC due to developing antifungal resistance is very significant for appropriate treatment and to prevent the spread of VVC.

Streptococcus pyogenes is one of the most important causes of bacterial pharyngitis. Asymptomatic carriage of this organism especially among schoolchildren is a common issue. Study of the prevalence and antimicrobial susceptibility pattern of the flora strains, as clinical indicators, are useful for treatment of streptococcal infections. The aim of this study was to determine the prevalence and resistance pattern of S. pyogenes isolates detected from throat of healthy children in Tehran. After filling a questionnaire including general information, from preschoolers, primary school students and school age children referring to the follow up center of the Ali-Asghar hospital of pediatrics, throat samples were collected from 5-15 year old eligible children by a sterile cotton swab. Then the samples were immediately seeded onto %5 sheep blood agar media. The plates were streaked and incubated appropriately after transferring to the laboratory. Biochemical and serological identification of isolates were done and then Antimicrobial susceptibility pattern of all identified isolates was determined by the disk diffusion method. Finally, Penicillin, Erythromycin and clindamycin MICs were determined by the E-test method for all isolates.The total number of 423 sample swabs were collected during a period of 6 months, showing the carriage rate of %5.7(n=24).Using chisquare test showed that there were no significant differences in carriage rates between the age sub groups (p=0.095). All isolates were sensitive to Penicillin, Cefotaxime, Erythromycin, Vancomycin, Azithromycin and Clindamycin. The rate of intermediate sensitivity and resistance to Tetracycline was 25 and 12.5%, respectively. Two isolates had intermediate sensitivity to each of the agents Oflxacin and Chloramphenicol. The MIC level of Penicillin for all isolates were ≤0.016 μg/ml, and MIC level of clindamycin and erythromycin for all isolates were ≤0.25 μg/ml, which were in sensitive range.It is concluded that in contrast to thepublished reports about rising penicillin MIC and resistance to erythromycin, Penicillin remains the first choice of drug for streptococcal infections and also macrolides and lincosamides can be considered as the alternative choice of drug in allergic patients.

Pasteurella multocida is known as one of the main organisms causing pneumonia in sheep. As immunity in pasteurellosis is serogroup specific, identification of prevalent capsular group among endemic areas is essential. The aim of this study was to molecular identification and determine of the capsular type of the P. multocida strains isolated from sheep pneumonia in Iran. Bacteriological and biochemical characterization was confirmed by species specific PM-PCR. Genomic DNA was extracted by boiling method. Capsular typing was conducted by using type specific primers via Cap-PCR method. The PCR product was sequenced and analysed by BLAST software. The biochemical identification was confirmed by a species-specific PCR assay (PM-PCR). According to Cap-PCR results, all of the 52 P.multocida isolates belonged to the capsular type A. The PCR amplified a fragment of 1044 bp from all of tested isolates. The sequence alignment of the CAP-PCR product showed a high similarity (>98%) with the published sequences of P.multocida hya gene in the Gene Bank. It was found that capsular type A is dominant among P. multocida isolates from sheep pasteurellosis in endemic areas of Iran. Investigation on preparation and evaluation of an effective sheep pasteurellosis vaccine by using ovine isolates of P.multocida capsular type A is recommended.

Microbial biofilms has remained a major complication of tracheal intubation in patients requiring ventilator equipment. The aim of this study was to characterize bacterial and fungal biofilms in endotracheal tubes from intensive care unit (ICU) patients in Ahwaz, Iran. In this cross-sectional descriptive study, patients admitted to ICU that required mechanical ventilation for at least 24 hours were evaluated. Specimens were collected from tracheal tubes of patients with endotracheal aspiration, when they had clinical manifestation of pneumonia. The specimens were microbiologically investigated and the bacterial and fungal isolates were identified by using standard cultural and biochemical tests. In total, 350 cases had tracheal tube aspirate positive cultures. The most of isolates are known to cause colonization of endotracheal tube included: Coagulase negative staphylococci (18.2%), E.coli (18%), Enterobacter spp. (16.2%), Pseudomonas spp. (14.6%), Acinetobacter spp. (9.7%), S.aurous (8.1%), Klebsiella spp. (6.7%), and Serratia spp. (0.4%). 7.4% were colonized with Candida spp. that the most common species was C.albicans (42.3%). The coagulase negative staphylococci species identified by mass spectrometry were: S.epidermidis (64%), S.haemolyticus (17.1%), S.lugdune (3.1%), S.warnerii (6.25%), S.hominis (6.25%), S.pasteur (3.1%). There was significant association between duration of being intubated and S.aurous, Enterobacter spp. (P=0.002). The presence of bacterial and fungal biofilms of endotracheal tube suggests that it may be important in biofilm development and may provide a therapeutic target for the prevention of ventilator-associated pneumonia.

Biogenic reduction of silver ion to base metal is quite rapid, readily conducted at room temperature and pressure, and easily scaled up. Synthesis mediated by plant extracts is environmentally benign. The objective of this study was to synthesis of silver nanoparticles (Ag-NPs) using leaves aqueous extract of Nasturtium Officinale R. Br. (NO) and its antibacterial activity. X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were performed to determine the formation of Ag-NPs. XRD confirmed the crystalline nature of the nanoparticles of 22 nm size. The XRD peaks at 38ºC, 44ºC, 64ºC and 77ºC can be indexed to the (1 1 1), (2 0 0), (2 2 0) and (3 1 1) Bragg’s reflections of cubic structure of metallic silver, respectively. Antibacterial activities of Ag-NPs were tested against the growth of Gram-positive (S.aureus) using SEM. The inhibition was observed in the Ag-NPs against S.aureus. The results of SEM showed that most of S. aureus was damaged and extensively disappeared by the addition of Ag-NPs. The results confirmed that the NO is a very good eco-friendly and nontoxic source for the synthesis of Ag-NPs.

Herpes simplex virus (HSV) causes a wide range of pathologies in the human central nervous system (CNS) such as stroke. It was proposed that there is an association between HSV infection and stroke with different results reported by the researchers using different methods. This study aimed to investigate the frequency of HSV among stroke patient and control groups. We detected HSV in 28 stroke patients and 28 controls that admitted in Beheshti, Emam Reza, Rajaee and Emam Sajad Hospital in 2013 north of Iran. DNA was extracted from blood samples and the infection with HSV was examined by PCR technique. The results obtained by this study showed that 15(53.6%) out of 28 in patients were infected by HSV, while the number of control samples infected by this virus was 9(32.1%). Statistical analysis has shown that there is not any significant association between the frequency of HSV and stroke, while in other studies the significant association between HSV and stroke has been demonstrated. These contradictory results could be due to the use of different diagnosing techniques, sample type and epidemiological differences.

Some parasites can be transferred from fish to human via eating of contaminated meat and make serious problems in consumers. In the present study zoonotic parasites of abdominal cavity in pike-perch, Sander lucioperca, in south eastern part of the Caspian Sea have been surveyed. In this regard, 30 fish were caught by purse seine net and abdominal cavity, digestive tract and other organs (kidney, spleen, liver, gonads and mesentery) of specimens were fully examined for helminthic parasites. Totally two zoonotic nematodes including Anisakis simplex and Eustrongylides sp were isolated from pike-perch. According to the result, 46.67 % of specimens were infected at least with one type of mentioned parasites. In this study the prevalence of Anisakis simplex and Eustrongylides sp infections in pike- perch were recorded as 36.67 % and 23.33 %, respectively. Mean intensity of parasite infection were calculated as 12.13 ± 5.8 and 2.57 ± 1.51, respectively for Anisakis simplex and Eustrongylides sp in pike-perches. This study described that the pike-perches in south-eastern part of the Caspian Sea are infected with mentioned zoonotic parasites, so health care of consumers in this area should be considered.

Toxoplasma gondii as an apicomplexan zoonotic parasite is able to infect humans and almost all other warm-blooded animals. Wild and domestic felids are the main definitive hosts. Also, canids such as dogs and jackals have been introduced as mechanical vectors since T. gondii oocysts can pass their intestinal tract and spread by feces in environment. Toxoplasmosis is a common zoonotic disease in Iran especially in North humid regions of Iran with 70% prevalence. The goal of this study was to evaluate the T. gondii antibody in jackals from Golestan province in East-North of Iran in order to analyze wild canids’ role in T.gondii’s life cycle. Blood samples obtained from 40 killed golden jackals. After separation of serum samples, the presence of T.gondii antibody was evaluated by ELIZA kit. T.gondii antibody has been detected in 31 out of 40 (77.5%) serum samples. Most positive jackals’ sera belong to older jackals. The T. gondii seropositivity was the same in male and female jackals.The relatively high prevalence of T. gondii in the samples of golden jackals gives valuable insight to T. gondii epidemiology and is useful for managing practical prevention and control programs.

Mycoplasmas hominis, Mycoplasmas genitalium and Ureaplasma urealyticum are associated with infections of the genitourinary tract, reproductive failure, and neonatal morbidity and mortality. A multiplex PCR was developed for simultaneously detection of these Mycoplasmas species in a single amplification reaction. The total number of 104 samples was collected from 104 women’s genital specimens with urogenital infections for identification of M.hominis, M.genitalium and U.realyticum by multiplex PCR. The High Pure PCR Template Preparation Kit purified nucleic acids from 100 μl of specimen (American, Roche Company). In addition to the kit, boiling method was used to extraction of DNA from samples. UUA2 and UUS2 primers were used for urease gene amplification of U.urealyticum, MH1 and MH2 used for 16S rRNA gene amplification of M.hominis, and Adhesionproteingene (MgPa) used for 16S rRNA gene amplification of M.genitaliumin all samples. The number of 28 samples (27%) was positive for Mycoplasmas. M.hominis, M.genitalium,and U.urealyticum were detected in 8.7, 3.9, and 14.5 percent of samples, respectively. The accumulated frequencies for M.hominis, M.genitalium,and U.urealyticum were 9(8.7%), 4(3.9%), and 15(14.5 %), respectively. The results of this study revealed that Multiplex PCR is a highly sensitive, specific and cost-effective test for screening of genitourinary tract infections.

The aim of the present study was to isolate cyanobacteria from oil refinery waste water and detection of antagonistic activity of their extracts on four species of pathogenic bacteria. The cyanobacterium was isolated and purified on Blue green algae medium number 11 (BG-11) medium. Methanol and water extracts prepared from the cultured cyanobacterium after 45 days growth on BG-11 medium. The bioactive antagonistic effect of extracts was investigated on Escherichia coli (PTCC 1399), Pseudomonas aeruginosa (PTCC 1707), Bacillus cereus (PTCC 1015) and Staphylococcus aureus (PTCC 1112) via well diffusion method. The chemical composition of the effective extracts was detected by gas chromatography Mass spectrometry (GC-MS). The isolated bacterium detected as Oscillatoria based on microscopic morphological characteristics. The methanol extract of the cyanobacterium showed considerable antagonistic effect on Gram-negative bacterial species (growth inhibition zone of 22.33±0.4 mm for Escherichia coli (PTCC 1399), and 18.6±1.52 mm for Pseudomonas aeruginosa, (PTCC 1707); while little effect on Gram-positive bacterial species (growth inhibition zone of 9.3±0.57 mm for Bacillu scereus (PTCC 1015) and 7.9±0.3 mm Staphylococcus aureus (PTCC 1112). The water extract of the cyanobacterium had no antagonistic effect on all experimented bacterial species. The chemical composition of the methanol extract detected as: 28.11% Dodecamethyl-cyclohexasiloxane, 25.76% Hexasiloxane, 3.75% Tetracosamethyl-cyclododecasiloxane (three related compounds) and 3.91% Bisabolol oxide A (unrelated compound). Minimal nutritional and environmental requirement, are advantages which set cyanobacteria as suitable candidates for production of antiviral, anti-tumor and antibacterial bioactive materials.