Epidemiological, molecular characterization and risk factors of human brucellosis in Iran

Objective: To determine epidemiological, molecular characterization, and potential risk factors of human brucellosis. Methods: This descriptive study was carried out in the clinical setting in Iran between 2017 and 2018. A total of 297 participants enrolled in the study. The sample size was calculated based on the occurrence rate of brucellosis in different areas. Patients were assessed using serological tests and conventional culture methods. Phage and multiplex PCR methods typed all of Brucella isolates. Potential risk factors of disease were determined. Results: A total of 141 of 297 (47.5%) Brucella strains were isolated and all of them were detected as Brucella melitensis biovar 1. Based on serologic titers, high culture positivity was recorded at 1/640 titer (P< 0.006). The risk factors for brucellosis were patients older than 40 years (OR=2.23, 95%CI: 1.4-3.55, P=0.001), animal keeper (OR=7, 95%CI: 1.51-32.41, P=0.005), housewife (OR=8.76, 95%CI: 1.85-41.37, P=0.002), farmer (OR=6.42, 95%CI: 1.21-33.97, P=0.019), and contact with animal (OR=1.31, 95%CI: 0.60-2.85, P=0.005). Conclusions: To the best of our knowledge, this is the first comprehensive report from Iran presenting the detection of Brucella species by the multiplex PCR. Brucella melitensis biovar 1 is still the dominant causative agent in Iran. The consumption of unpasteurized dairy products, living in rural areas, and animal contact were risk factors of brucellosis.

Serotyping, antibiotic susceptibility and related risk factors aspects of nasopharyngeal carriage of streptococcus pneumoniae in healthy school students

Streptococcus pneumoniae is an important problem worldwide and nasopharyngeal colonization plays significant role in pneumococcal infections. The aims of this study were to determine the nasopharyngeal colonization rate, serotyping, antibiotics susceptibility and study the risk factors for nasopharyngeal colonization with S. pneumoniae in students in Kashan, Iran. A cross-sectional study was conducted on children aged 7 to 19 years from December 2011 to November 2012. Nasopharyngeal swabs were plated onto brain heart infusion agar plates with 5% sheep blood and 4 micro g/ml of gentamycin. Antimicrobial susceptibility profiles were determined on Mueller-Hinton agar in accordance with CLSI. S. pneumoniae strains were investigated for the presence of the most common pneumococcal serotypes using a multiplex polymerase chain reaction. 13.9% were found to be carriers. The most prevalent serogroups were 19F [30%], 6A/B [18.9%], 15A [16.5%], 11 [11.3%], 23F [8.2%], 1 [6.2%], 19A [3.4%], and 35B [2.4%]. Nine strains [3.1%] were non-typeable. The carrier rate was significantly higher in 12 to15 year old age group. Upper respiratory tract infections within the last month [OR=1.5, P<0.011], previous hospitalization [OR=1.6, P<0.001], previous antibiotic usage last two weeks [OR=1.89, P<0.001], rhinorea [OR=1.9P<0.001], male sex [OR=3.5 P< 0.001] and passive smoking [OR=1.56, P< 0.001] have been determined to be risk factors for S. pneumoniae carriage. The highest pneumococcal resistance was to tetracycline [25.4%]. All strains were susceptible to linezolid and levofloxacin. Our information leads to an important source to screen the future impact of pneumococcal vaccination on bacterial colonization

Prevalence of helicobacter pylori vacA, cagA, cagE, iceA, babA2, and oipA genotypes in patients with upper gastrointestinal diseases

Helicobacter pylori has been strongly associated with peptic ulcer diseases, chronic gastritis, ulcers, and reported as a risk factor for gastric cancer, too. The vaculating cytotoxin [vacA], the cytotoxin associated genes [cagA], the induced by contact with epithelium factor antigen [iceA gene], blood adhesion binding antigen [babA2], and outer membrane protein oipA have been described as different virulence factors of H. pylori. The aim of this study was to investigate the prevalence of the vacA, cagA, cagE, iceA, babA2 and oipA genotypes of H. pylori isolates from patients with upper gasterointestinal problem or dyspepsia. H. pylori isolated from endoscopic biopsies obtained from 222 studied patients. PCR was done only on cultured positive samples. The vacA alleles, cagA, cagE, iceA, babA2 and oipA genotypes were determined by PCR. The isolation rate of H. pylori strains from culture of gastric biopsies was 16.7%. The vacA alleles s1, s2, m1 andm2 were detected in 20 [54.1%], 14 [37.8%], 9 [24.3%] and 23 [62.2%] isolates, respectively. VacA s1c genotype was detected in 70.3% of isolates. s1m2 was the most frequent vacA allelic combination in the examined H. pylori strains. ThecagA gene was detected in 62.2%, cagE in 40.5%, iceA1 in 48.6%, iceA2 in 16.2%, oipA in 81.1% [95% CI: 0.0902-0.1798] and babA2 in 94.6% [95% CI: 0.113- 0.207]. A significant correlation was observed between vacAs1 and cagA genotypes [P < 0.008], vacAs1/cagE [P = 0.001], vacAs2/cagA [P < 0.047], and vacAs2/cagE [P = 0.016] with Non-ulcer dyspepsia; but there were not observed any correlation between other virulence markers. No significant correlation was found between the existence of vacA, cagA, cagE, iceA, babA2, and oipA genes with peptic ulcer diseases and non-ulcer dyspepsia groups of studied patients

Detection of ESBLs and MDR in Pseudomonas aeruginosa in a tertiary-care teaching hospital

Pseudomonas aeruginosa is characterized as an important nosocomial pathogen with increasing antimicrobial resistance. The multidrug-resistant [MDR] phenotype in P. aeruginosa is increasing worldwide. The purpose of this study was to evaluate the prevalence of antibiotic susceptibility, ESBLs [Extended spectrum beta lactamases] producing and multidrug resistant [MDR] P. aeruginosa, isolated from clinical specimens of patients and environment of hospital. This descriptive study was carried out on 76 isolates of P. aeruginosa from a 500-bed tertiary-care general teaching hospital in Kashan, Iran in 2010. Susceptibility testing according to the CLSI [Clinical Laboratory Standards Institute] recommended to eight antipseudomonal agents was performed. ESBLs producing strains were confirmed by double disk diffusion method. Multidrug-resistant isolates were defined as those resistant to three or more classes of antipseudomonal agents. The highest resistance rates from the isolated P. aeruginosa were shown against piperacillin, imipenem, cefotaxime, ceftriaxone, gentamicin, ceftazidime, aztreonam, and ciprofloxacin, respectively. Seven isolates [9.2%] were ESBL producers. More than 30% of the isolates were resistant to at least three classes of antibiotics, and 13% of MDR strains were resistant to all eight tested classes of antimicrobials. Among the total isolates, 6.6% were susceptible to all studied agents, and 9.2% were resistant to a single agent. The isolated bacteria from the tracheal samples showed the highest MDR rate. Prevalence of P. aeruginosa producing ESBL and MDR strains from our clinical samples and environment is still low

[Antifungal activities of fluconazole and ketoconazole agents against Malassezia species]

Malassezia, a yeast-like fungus found in normal skin flora is known to be associated with various skin diseases, along with systemic infections. Our aim was to determine the in -vitro susceptibility of Malassezia spp. to ketoconazole and fluconazole. In this study, we identified 99 Malassezia isolates from patients with pityriasis vesicular by morphological and biochemical criteria. In vitro susceptibility testing was in macro-broth dilutions, conducted based on the National Committee for Clinical Laboratory Standards [NCCLS] M27-A proposed standard. The results were analyzed statistically by Mann-Whitney. The Malassezia isolates were identified as M. globosa [42], M. furfur [39], M. obtusa [10], M. sympodialis [6], and M. slooffiae [2]. The rate of MFC of ketoconazole against Malassezia spp. was 0.06-2 micro g/ml, while the MFC of fluconazole against Malassezia spp. was 2-64 micro g/ml. The minimal inhibitory concentration [MIC90] of ketoconazole against Malassezia spp. was 0.03-1 micro g/ml, while the minimal inhibitory concentration [MIC90] of fluconazole against Malassezia spp. was 0.5-32 micro g/ml. Although fluconazole can be an effective treatment option for pityriasis versicolor, in our study, fluconazole MICs were higher than ketoclonazole

Comparison of culture and microscopic methods by PCR for detection of Mycobacterium tuberculosis in sputum

It is difficult to diagnose Mycobacterium tuberculosis infection due to a lack of rapid, sensitive, and specific tests. Newer methods, which are easy and reliable, are required to diagnose TB at an early stage. Our aim is to evaluate the polymerase chain reaction [PCR] technique, using primers directed against the IS6110 gene, for the detection of M. tuberculosis in the sputum samples, and calculate the sensitivity and specificity of PCR. A total of 248 sputum samples from patients suspected of mycobacterial diseases were studied. DNA was extracted by boiling method. IS6110 PCR method by a specific pair of primers designed to amplify 123bp and 245bp sequences of the insertion sequence, 6110, in the M. tuberculosis genome was used to analyze sputum samples. Totally, 32 [12.9%] samples had positive culture. PCR yielded a sensitivity of 93.8% and specificity of 99.1% for the diagnosis of TB, when diagnosis was confirmed by culture. There were 2 out of 32[6.3%] PCR-positive cases among the patients with non-TB disease. We concluded that the performance of an IS6110 PCR assay is valuable in the rapid diagnosis of tuberculosis

Isolation and identification of Malassezia spp. in pytiriasis versicolor in Kashan, Iran

Pityriasis versicolor [PV] is a chronic superficial fungal disease caused by Malassezia spp. The incidence is as high as 30-40% in tropical climates. Epidemiological data suggest geographical variations in the rate of the isolated species from PV. Our aim was to identify Malassezia spp. from PV patients in Kashan, Iran. Isolates of Malassezia were collected from 118 PV patients [75 males and 43 females]. A direct microscopy with KOH and methylene blue was carried out. Cultures were made in modified Dixon agar medium and the isolates were identified by macroscopic and microscopic features, physiological characteristics [catalase test] and biochemical criteria [esculin and lipid assimilation tests]. Data were analyzed statistically by software SPSS [version 11] and Fischer's exact and descriptive statistical tests. The average age of 118 patients in this study was 28.42 +/- 8.53 years. The percentages of patients in this study were 64.4 and 35.6 for men and women respectively. Hyperhydrosis was reported as the most important finding with 58.1%. Back [42.2%] and extremities [7.4%] were the highest and the lowest involved parts respectively. The isolates found were M. globosa [43.8%], Malassezia furfur [38.4%], M. obtusa [9.8%], M. sympodialis [6.3%], and M. slooffiae [1.7%]. From these findings it was suggested that M. globosa presents the main species implicated in the pathogenicity of PV and M. furfur as the second agent of importance

prevalence of nasal carriage methicillin-resistant staphylococcus aureus in hospitalized patients

To determine the nasal colonization of methicillin-resistant Staphylococcus aureus in hospitalized patients. This descriptive study was carried out on 100 hospitalized patients at Shahid Beheshti Hospital in Kashan in 2007. The nasal samples were collected by sterile swabs, and transferred to Brain Heart infusion [BHI] culture medium and immediately refered to the microbiology lab in Kashan University of Medical Sciences. Samples were inoculated on blood agar and manitol salt agar media. Identification of the isolates was done by standard biochemical tests. Oxacillin susceptibilities of S. aureus isolates were determined using Mueller-Hinton oxacillin agar screen plate. The results were analyzed statistically by chi Square and Fischer's exact tests. The prevalence of nasal carriage of Staphylococcus aureus and MRSA were 38% [38 out of 100], and 52.6% [20 out of 38], respectively. The results showed that by urinary tract catheterization [P=0.005], administration of any antibiotic [p=0.008], history of diabetes mellitus [p=0.0303], and hospitalization time more than one week [p=0.0009] were the main predisposing factors for nasal colonization of MRSA. The ICU ward was the principle ward of nasal colonization by both Staphylococcus aureus [75%] and MRSA [100%], followed by infectious diseases ward with rates of 64.7% and 75%, respectively. The overall colonization rate of MRSA in the hospitalized patients in this study was high. A systematic selective screening of patients with high risk of carriage should be fruitful to implement barrier precautions and reduce cross-transmission