Iranian Journal of Microbiology
Volume:6 Issue: 2, Apr 2014

The prevalence of Vibrio parahaemolyticus has been reported from Ponnani earlier, however incidence of multidrug resistant strains have been encountered recently in clinical laboratories. The source for such strains and their presence in this major fish landing centre has been investigated. Antibiotic sensitivity tests on isolates of V. parahaemolyticus isolated from three different substrates were conducted following disc diffusion method. Populations of V. parahaemolyticus (cfu/ml) were relatively high in sediment samples (7.67 ± 2.08), compared to shrimp (5.33 ±1.53) and water samples (3.67 ± 1.15). V. parahaemolyticus isolated from water showed relatively higher antibiotic resistance pattern compared to other two groups. The highest incidence of antibiotic resistance was recorded against cephalothin and nitrofurantonine; the lowest was against tobramycin, piperacillin and amikacin. Maximum multiple drug resistant (MDR) strains were encountered from water samples followed by shrimps. Results emerging from the present study clearly showed that Ponnani has a fairly good population of antibiotic resistant strains of V. parahaemolyticus. The present study provides an insight on the microbial population of V. parahaemolyticus in Ponnani harbour and warrants the need to develop control measures to reduce incidences of post-harvest contamination of seafood.

The toxin co-regulated pilus A (TcpA) has been described as a critical pathogenicity factor of Vibrio cholerae. TcpA is a candidate for making subunit vaccine against cholera. The aim of this study was to produce a candidate vaccine by expressing recombinant TcpA in E. coli. In this study, the toxin co-regulated pilus A gene from EL-Tor, V. cholerae subspecies, was amplified by PCR and sub-cloned into prokaryotic expression vector pGEX4T1. E. coli BL21 (DE3) was transformed with pGEX4T1- TcpA and gene expression was induced by IPTG and purified by GST resin. The integrity of the product was confirmed by Western blot analysis using a standard rabbit anti-V. cholerae antibody. Sera reactivity of infected individuals was further analyzed against the recombinant TcpA protein. The concentration of purified recombinant protein was calculated to be 8 mg/L of initial culture. The integrity of product was confirmed by Western blot analysis using a standard rabbit anti V. cholerae antibody. Sera reactivity of infected individual was further analyzed against the recombinant TcpA protein. The obtained data indicated that recombinant TcpA protein from V. cholerae was recognized by patient serum and animal sera. These results show that the recombinant TcpA is antigenic and could be used in a carrier host as an oral vaccine against cholera.

Urinary tract infections (UTIs) are the most common infections in renal transplant recipients and are considered a potential cause of bacteremia, sepsis, and affects graft outcomes. The aim of the present study was to determine the incidence of UTI among renal transplant recipients and investigation of antimicrobial susceptibility pattern of causative agents. In total, 1165 patients from March 2009 to December 2012, in transplant center of Golestan Hospital, Ahvaz, Iran, were investigated. Qualitative urine cultures were performed for all cases, causative microorganisms were identified and colony count was performed according to the standard protocol. Antibiotic susceptibility testing was then performed to determine the susceptibility pattern of recovered bacteria from confirmed UTIs. UTI was diagnosed in 391 patients (33.56%). Gram-negative bacteria were the most prevalent isolated microorganisms with E. coli (43.53%), followed by Enterobacter spp. (35.37%) as the major organisms. Among Gram positives, Coagulase-negative Staphylococci was isolated from 6.8% of cases. The rate of resistance to all tested antibiotics was highest in Enterobacter spp., however the most common resistance were seen against cefixime, cephalotin, and cotrimoxazole in all tested gram negatives. the rate of UTIs among renal transplant recipients was noticeable in this study with high antibiotic resistance. Multi-resistant bacterial infections are potentially life-threatening emerging problem in renal transplantation. Prophylactic measures must be applied to patients at greater risk.

Staphylococcus aureus is an important infection in hemodialysis patients. We studied the prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) and its antibiotic resistance pattern in patients receiving hemodialysis as well as in dialysis unit staff. From June to September 2012, we evaluated 74 cases including 61 patients on hemodialysis and 13 dialysis unit staff. Nasal swabs were taken from all cases and were cultured on a blood medium agar. We identified S. aureus based on conventional laboratory methods. For antimicrobial resistance patterns, we used disk diffusion method. Oxacillin MIC, oxacillin and cefoxcitin disk diffusion methods were used for detection of MRSA. Disk approximation test (D-test) was applied for the frequency of erythromycin induced clindamycin resistance. S. aureus carrier state was determined in 12 of the 61 patients on hemodialysis (19.67%) and 5 of the 13 dialysis unit staffs (38.46%). In hemodialyzed patients, MRSA and MSSA carrier of S. aureus were 6.56% and 13.11%, respectively. All nasal carriage states in studied staffs were MSSA. All isolated S. aureus were found to be sensitive to vancomycin, teicoplanin, and rifampin. However, reduced sensitivity of MRSA isolates to other antibiotics was noted. Resistance frequencies to tested antibiotic was as follows: cefteriaxone and penicillin (100%), tetracycline and doxycilin (75%), gentamycin, cloxacillin, and cefazolin (50%), ciprofloxacin, trimethoprim-sulfamethoxazol, erythromycin, and clindamycin (25%). The resistance rate of isolated MSSA against tested antibiotics was lower than isolated MRSA. Inducible clindamycin resistance was shown in 25% of identified MRSA strains. S. aureus nasal carrier state was lower than former reports from other parts of Iran. The antibiotic resistance patterns also differed, perhaps due to different pattern of administering antibiotics at our hospital. Screening of these patients should be noted as a health priority and microbial sensitivity tests should be considered in order to optimize treatment options.

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is increasingly reported worldwide. We aimed to determine the frequency of invasive CA-MRSA in children admitted to the pediatric wards of Imam Reza and Ghaem hospitals of Mashhad, Iran. In this retrospective study, data regarding S. aureus isolates from pediatric patients’ sterile body sites (i.e. blood‚ joint, bone and lymph node aspiration) were retrieved in a time period from March 2006 to March 2012. Disc diffusion data was analyzed to determine the resistance pattern of the isolates, and differentiation between community-acquired and nosocomial S. aureus was done according to CDC guidelines. Twenty three invasive community-acquired S. aureus isolates from sterile body sites were identified, of which 17 (74%) were CA-MRSA. The CA-MRSA isolates showed high frequency of resistance to non-β-lactam antibiotics (71% to erythromycin‚ 53% to co-trimoxazole, 44% to gentamicin and 36% to ciprofloxacin). In this study, the majority of invasive community-acquired S. aureus isolates were found to be CA-MRSA. Therefore, we recommend that primary treatment should be with antibiotics such as clindamycin, vancomycin, linezolid or daptomycin for any invasive infection suspected to be caused by S. aureus in these two hospitals.

Febrile convulsion is a common disorder in children. Viral infections such as human herpes virus 6 (HHV-6) which results in roseola infantum may contribute to developing seizure. The objective of this study was to determine the prevalence of HHV-6 by detecting DNA in cerebrospinal fluid (CSF) of children with febrile convulsion and without any rash of roseola infantum. In this descriptive cross-sectional study, CSF of 100 children younger than 2 years of age with febrile convulsion was evaluated for detecting HHV-6 DNA by PCR. All of them were referred to emergency ward in Pediatric Medical Center from March 2010 to March 2011. General information, clinical manifestations, laboratory tests and outcomes were collected in the questionnaires. One hundred children including 59 males and 41 females were evaluated. HHV-6 was detected from CSF in six patients (6%) by PCR. Mean age was 8 months old. All children were younger than 12 months old. The most common primary manifestation was fever alone. None of them had rash. Majority of cases occurred in winter. All patients recovered without any encephalitis. These findings showed that primary infection with HHV-6 is frequently associated with febrile convulsion in infants which may be at risk for subsequent development of epilepsy.

Backgrounds and Classified as low pathogenic avian influenza (LPAI) viruses, the H9N2 subtype causes severe respiratory disease in poultry farms and occasional respiratory disease in humans. In this study, the neuraminidase (NA) gene of three Avian Influenza (AI) H9N2 strains isolated from poultry farms in Iran during 2010-11, as well as other reported Iranian H9N2 isolates, were genetically analyzed and their nucleotide changes were evaluated. The NA gene of three AIVs were sequenced and evaluated for genetic characteristics and phylogenetic relationship. One new potential glycosylation site (PGS) at amino acid position 306 was observed in one of the studied isolates (A/Chicken/Iran/N102/2011). Antigenic sites of NA in Iranian H9N2 isolates have varied in a yearly manner. The Iranian isolates can be divided into 2 main subgroups; 11-T like subgroup viruses isolated mainly during 1998-2004 and second subgroup viruses isolated during 2004-2009. Interestingly, the three studied isolates fell into a third subgroup. The nucleotide sequences of the three studied isolates showed high identity to recent Pakistani H9N2 isolates (94.5-97%) compared to former Iranian AIV isolates (89-94%). High frequency of substitutions in the NA gene of studied isolates in recent years and effects of those substitutions on the pathogenicity of AI virus highlight the need to continue surveillance of genetic characteristics of AIV H9N2 in Iran.

Onychomycosis is a common fungal infection which has been conducted in many parts of the world. The aim of this study was to evaluate the epidemiology and to identify the aetiological factors of onychomycosis in Mazandaran province, Iran. During the period of 10 years (2003–2012) 1100 patients suspected to onychomycosis, referred to the Mycology Laboratory of the Referral Laboratory and Boali Sina Hospital of Mazanadaran University of Medical Sciences, Sari, Iran, were assessed for the presence of onychomycosis with mycological examination based on conventional techniques. Among 1100 subjects (398 males and 702 females, aged 1-88 years) onychomycosis was diagnosed in 625(56.8%) cases. Among cases of onychomycosis, laboratorial confirmation was reached through direct examination with positive cultures in 464 samples (74.3%), while only by positive direct exam in 114 cases (18.2 %) or just positive culture in 47 cases (7.5%). The results of fungal culture revealed Candida spp. isolated in (61.9%) of the cases as the most common agents of onychomycosis while among dermatophytes, Trichophyton mentagrophytes was found in 17.7% followed by T. rubrum (1.7%), Epidermophyton floccosum (0.7%), T. violaceum (0.2%), T. verrucosum (0.2%), T. tonsurans (0.2%) and Microsporum gypseum (0.2%). Among the non-dermatophyte moulds, Aspergillus spp. was the most prevalent species 14.2%. The results demonstrated that onychomycosis was proved in 625(56.8%) cases and the most common isolates were Candida spp., followed by dermatophytes and moulds. This epidemiological data collected may be useful in the development of preventive and educational strategies.

Phosphlipases are a group of enzymes that breakdown phosphatidylcholine (phospholipids) molecules producing second products. These produced products have a divers role in the cell like signal transduction and digestion in humans. In this research the effect of phosphatidylcholine on the expression of plc genes of A. fumigatus was studied. The plc genes of this fungus were also interrogated using bioinformatics studies. Real-time PCR was performed to study the expression of plc genes and these genes were interrogated using bioinformatics studies. There was more significant expression for all three plc genes when A. fumigatus was grown on the presence of phosphatidylcholine in the medium. The sequence of plc genes of A. fumigatus was also interrogated using bioinformatics analysis and their relationship with the other microorganisms was investigated. Real-time PCR revealed that afplc1, afplc2 and afplc3 were up-regulated in the presence of phosphatidylcholine. In this study we suggest either the plc’s of A. fumigatus were present in an ancestral genome and have become lost in some lineages, or that they have been acquired from other organisms by horizontal gene transfer. We also found that plc’s of this fungus appeared to be more closely related to the plant plc’s than the bacterial plc’s.

The present work was carried out to investigate the ability of Spirulina platensis to produce antimicrobial substance against bacteria and fungi. The cells of the cyanobacterium were subjected to different extractions and the purified antagonistic compound proved to be effective against broad spectrum of bacteria and fungi. The antagonistic compound was purified using thin layer chromatography. The results indicated that the IR spectrum showed bands at 1269 cm-1, 1414 cm-1 (C-O-C), 1643 cm-1 (CO of amide),1563 cm-1 (C=C) and broad band 3441 cm-1 (of OH and NH)., 1HNMR showed δ 0.8 (-CH3), δ 1.2 (-CH2), δ 4.2(-OH), δ 7.2(-NH), δ 7.4 and δ 7.7 (aromatic CH)., Mass spectrum showed molecular ion beak at m/z = 341 (abundance (0.03%). Also, the elemental analysis gave molecular formula,C15H18NO8. The purified antimicrobial compound produced by S. platensis was more active against Gram positive, Gram negative bacteria and unicellular fungi, C. albicans. The highest biological activity was recorded against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Aspergillus niger. The results of this investigation proved that cyanobacteria could be a good source for production of antimicrobial agents which could be effective when compared with contemporary antimicrobial compounds.

The aim of our study was to characterize gizzard Lactobacillus fermentum-group strain on the basis of their phenotypic profiles regarding characteristics of lactobacilli. In addition, their in vitro potential probiotic properties were evaluated. The lactic acid bacteria were isolated and identified from gizzard contents of Algerian local poultry using criteria of Bergey’s Manual of Determinative Bacteriology and using methods and criteria of Sharpe. The strains were further characterized by tolerance to low pH and bile, coaggregation potential and adhesion to intestinal mucous. The antagonistic activity against some Enterobacteriaceae strains from poultry origin was also evaluated.Results and Among the strains identified, both physiological and biochemical characteristics differed noticeably. The strains coded LP3 and LP10 survived simulated gastrointestinal conditions and were considered to be acid and bile tolerant. The majority of the strains exhibited antagonistic activity towards Escherichia coli, Klebsiella spp., Enterobacter spp., Shigella spp., Salmonella spp and Citrobacter spp. The best co-aggregation properties were obtained with two isolates. Lb. fermentum LP3 alone showed adherence specificity to the chicken intestinal epithelium.

Bacillus species are attractive industrial organisms due to their rapid growth rates leading to a short fermentation cycle and for their capacity to secrete important enzymes and proteins such as xylanase into the extracellular medium. Considering the industrial importance of xylanase, in this current study, Bacillus spp. were isolated from different soils and were screened for their xylanase production. Bacillus isolates used in this study were obtained from a national screening program carried out during 2006-2007 in which soil samples that covered areas throughout the interior of Syria were collected. The prepared inoculum from each of Bacillus isolates was aliquoted onto xylan agar plates, incubated at 30°C for 72 h and screened for xylanase synthesis. Xylanolytic isolates were selected depending on the clear zones of xylan hydrolysis. Fifteen isolates having the highest clearing zone were determined and grown in a solid state fermentation. Of the 15 isolates, three bacilli namely SY30A, SY185C and SY190E that showed maximum xylanase production, were identified using the 16S rDNA sequencing method. According to 16S rDNA gene sequence data, the closest phylogenetic neighbor for SY30A was Bacillus pumilus and for SY185C and SY190E isolates was Bacillus subtilis. Optimal pH and temperature for xylanase activity was 7.0 and 55°C for SY30A and 6.0 and 60°C for SY185C and SY190E, respectively. Under these conditions, the following activities were found to be around 1157 ± 58, 916 ± 46 and 794 ± 39 (U/g) for SY30A, SY185C and SY190E, respectivly. Selected local Bacillus isolates were found to be a potential source of xylanase which was proven to be quite suitable for multiple biotechnological applications. These isolates might after extensive optimization steps be an alternative to commercially available strains.