[Fungus paranasal sinusitis in non-immunocompromised patients in Tehran, Iran [2006-07]]

Incidence of fungal infections particularly fungal sinusitis is increasing in Iran and identification of causative agents is essential for its control and treatment. This study was carried out to determine the fungus paranasal sinusitis in non-immuno-compromised patients in Tehran, Iran. This cross-sectional study was done on 108 patients [73 males, 35 females] with chronic sinusitis ranged from 9 to 68 years, admitted to Amir Alam and Emam Khomeini hospitals in Tehran, Iran during 2006-07. Sinusitis in patients confirmed by radiologic images. Complementry information were obtained using questionnaires which including gender, job, presence of disposing disease diabetes and consumption immunocompromised drugs. Sinus samples were collected by washing and biopsy were carried out by two methods of fenestration and Cald-wel luc operations. Subsequently they were cultured on Sabouraud dextrose agar [SDA], SDA+chloramphenicol and blood agar [BA] media at 30 C and 37 C. Direct examination and fixative sample for histhologic evaluation was done and for colonies confirmation the slide culture method also was used. 8 cases [7.4%] were positive for fungal sinusitis with following sub type: 6 cases [Alternaria Spp], 1 case [Paecilomyces] and 1 case [Aspergillus flavus]. The most fungal sinusitis [5 cases] were observed in 30-39 years patients. Considering the prevalence of 7.4% fungal sinusitis and isolation of paecilomyces which is a rare subtype complematry investigation is recommended, in the field of research

[ effect of sub-minimum inhibitory concentration [S-MIC] of ciprofloxacin and ampicillin on hemolysin activity of Escherichia coli]

Sub-minimum inhibitory concentration [S-MIC] can induce changes in morphology, virulence factors and biochemical properties of bacterial pathogens. The goal of this study is to determine the Sub-MIC effect of ciprofloxacin and ampicillin on the haemolytic activity of E. coli. Two clinical isolates of E. coli with high haemolytic activity was selected. Changes in haemolytic activity of the isolates was assessed after exposing them to MIC and Sub-MIC of ciprofloxacin and ampicillin. Ciprofloxacin decreased haemolytic activity at 1/2, 1/4 and 1/8 Sub-MIC, whereas ampicillin showed no effect on haemolytic activity. We conclude that Sub-MIC concentrations of ciprofloxacin decreased the haemolytic activity of E. coli, whereas ampicillin had no such effect

[Prevalence of haemophilus influenzae biotypes and their clinical significance]

Haemophilus influenza can lead to several infections in humans. For example it can lead to meningitis, epiglottitis, pneumonia, cellulitis, bacteremia, septic arthritis and conjunctivitis. H. influenza can be classified into seven biotypes independent of their serotypes. Biotypes are determined by three tests including indol production, urease and ornithine decarboxylase. As specific biotypes are associated with different types of infections, sources and antimicrobial resistance patterns, this study was designed to evaluate biotyping in H.influenza and its relationship with the type of infection. In an 18 month period from April 2005 to September 2006, all clinical specimens that were candidate for Haemophilus isolation, were cultured on standard chocolate agar and blood agar with staphylococcal streak technique. Those isolates that showed the phenomenon of satellitism were biotyped by indol production, urease and ornithine decarboxylation tests. From 24 samples positive for Haemophilus influenza, 11 were isolated from eyes, 11 from paranasal sinuses, one from cerebrospinal fluid [CSF] and one from blood. The isolates from sinuses belonged to the biotype III, the biotype of 6 of the eye isolates was II and that of the other 5 biotypes were III, and the isolates from blood were type I. Another biotype was not isolated from these samples. In other studies, biotype I was the most frequently isolated biotype from CSF and blood. Biotypes II and III have been isolated from the eyes and sputum. The relationship between biotypes II and III in conjunctivitis is well documented. In this study, the most frequently isolated biotypes from conjunctivitis samples were II and III, type III was also common in sinusitis. Biotype IV has been isolated from genital tracts. Due to correlation of biotype and antimicrobial resistance, biotyping is recommended in Haemophilus isolates

Penicillin susceptibility testing of streptococcus pneumoniae by oxacillin disk screening method and standard broth microdilution method

Despite the widespread use of new antibiotics, Streptococcus pneumoniae still remains a significant cause of infection-caused morbidity and mortality across all age groups the world over. Isolates of Pneumococci that are resistant to Penicillin and other antibiotics are being found with increasing frequency. Rapid recognition of Penicillin-resistant strains in the laboratory is therefore critical to proper selection of antimicrobial therapy. The present study, carried out on clinical specimens, compared the Oxacillin disk screening test with the standard broth microdilution method in order to determine antibiotic susceptibility of Penicillin-resistant strains of Streptococcus pneumoniae. For the purposes of this study, 327 clinical samples were collected and Pneumococci strains were isolated from various parts of human body including blood, sputum, CSF etc. The minimal inhibitory concentration [MIC] of Penicillin G was determined using the standard broth microdilution method. The diffusion method [Kirby and Bauer] with 1 microg Oxacillin disk was used for first screening of Penicillin-resistant Pneumococci. A total of 61 S. pneumoniae strains were isolated from the clinical samples. The disk diffusion method classified 85% of the isolates as highly Penicillin-resistant and 15% as susceptible, while the microdilution method identified 19.6% susceptible to Penicillin, 16.2% moderately susceptible, and 18.1% highly resistant to Penicillin. Comparison of the two methods applied showed that the Oxacillin disk screen test was false-positive in 25% of the cases but the susceptibility of the strains to Penicillin as detected by the two methods did not show significant differences [p>0.05]. The high percentage of Pneumococci resistance to P-lactam antibiotics, particularly to Penicillin, necessitates the application of Oxacillin disk screening test as a cost-effecfive and rapid test and as an essential tool for initial diagnosis of resistant strains. The test is regarded as very sensitive but of low specificity because it does not distinguish between isolates highly resistant to Penicillin and those with intermediate resistance. It is, therefore, advisable that the standard microdilution test should be used for serious infections like meningitis or bacteriome

Detection of icaAD gene and biofilm formation in staphylococcus aureus isolates from wound infections

Wound infections are a common cause of staphylococcal infections. An ability of S.aureus is to adhere and form biofilm on host surfaces. Biofilm is an exopolysaccharide, a slime matrix around multiple layers of cells and is mediated by expression of the icaADBC operon. The present study evaluated the biofilm forming capacity and the presence of icaAD gene among S.aureus isolated from wound infections. Slime production assay was performed by cultivation on Congo Red Agar plate. In addition, Quantitative biofilm formation determined by microtiter plate assay PCR method used for detection of icaAD gene. Fifty strains were identified, 54% of the isolates produced black colonies on CRA plate, 52% were positive biofilm forming, and all strains carried the icaAD gene. Regarding the ability of S.aureus to form biofilms helps the bacterium to survive hostile environments within the host, suggests that biofilm production is a risk factor for infection. It is important in rapid diagnosis and treatment biofilm forming strains, because biofilm formation may lead to increased antimicrobial resistance and create a significant impediment to wound healing

Two novel mutations and predominant 35delG mutation in the connexin 26 gene [GJB2] in Iranian populations

Mutations in the GJB2 gene encoding Connexin 26 [Cx26] protein are a major cause for autosomal recessive non syndromic and sporadic deafness in many populations. In this study we have investigated the prevalence of the GJB2 gene mutations using nested PCR pre screening strategy and direct sequencing method. Two hundred and sixty autosomal recessive non syndromic and sporadic deaf subjects from 199 families in two provinces of Iran [Gilan and Khorasan] were studied. Altogether 14 different genetic variants were identified from which 2 were novel variant [327delG+G109G and 431insC]. Eight GJB2 mutations including 35delG, 235delC, W77X, R127H, M34T, V27I+E114G, L90P and delE120 were also found in 54 of 199 families [27%]. Four polymorphysms V27I, S86T, V153I and G160S also were detected. Thirty two of 199 families were observed to have GJB2 mutations in both alleles [16%]. The most common mutation was 35delG so that 43 out of 55 GJB2 mutations [78.2%] contained 35delG mutation