Microbiology
Meysam Manouchehrifar; Farzad Khademi; Hadi Peeri Doghaheh; shahram Habibzadeh; Mohsen Arzanlou
Abstract
Background & Objective: Staphylococcus aureus causes various hospital- and community-acquired infections. This study aimed to investigate the phenotypic and genotypic characteristics of erythromycin and inducible clindamycin resistance, virulence gene profiles, and spa types of S. aureus isolates ...
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Background & Objective: Staphylococcus aureus causes various hospital- and community-acquired infections. This study aimed to investigate the phenotypic and genotypic characteristics of erythromycin and inducible clindamycin resistance, virulence gene profiles, and spa types of S. aureus isolates collected from patients in Ardabil Province, Iran.Methods: A total of 118 clinical S. aureus isolates, including 50 (42.4%) methicillin-resistant S. aureus (MRSA) and 68 (57.6%) methicillin-susceptible S. aureus (MSSA) strains, were investigated. Resistance patterns were determined by the disk diffusion method and minimum inhibitory concentration (MIC) test. Inducible macrolide-lincosamide-streptogramin B (iMLSB) resistance was detected using D-test method. The polymerase chain reaction (PCR) was used to identify the virulence and resistance-encoding genes. Additionally, the spa types of the isolates were determined using the PCR, followed by sequencing.Results: In total, 49.1% (58/118) and 44% (52/118) of the isolates were resistant to erythromycin and clindamycin, respectively. Overall, 13.5% (16/118) of the isolates showed the iMLSB resistance phenotype. The ermC gene (72.4% [42]) was the most frequent erythromycin resistance-encoding gene, followed by ermA (60.3% [35]), ermB (60.3% [35]), ermTR (51.7% [30]), and msrA (15.5% [9]) genes among erythromycin-resistant isolates. The virulence genes hla, hld, sea, LukS PV, tst, seb, sed, eta, sec, and etb were detected in 93.2%, 74.5%, 70.3%, 32.2%, 29.6%, 17%, 8.5%, 8.5%, 5.9%, and 4.2% of the isolates, respectively. Ten different spa types were identified for 58 erythromycin-resistant S. aureus strains, of which t030 and t078 types were the most common types.Conclusion: A high frequency of macrolide- and lincosamide-resistant S. aureus isolates with different genetic backgrounds of resistance and virulence may be found in patients in Ardabil Province, Iran.
Microbiology
Shabnam khavandi; Mohsen Arzanlou; Roghayeh Teimourpour; Hadi Peeridogaheh
Abstract
Background & Objective: Carbapenem-resistant is Gram-negative bacteria representing a worldwide public health problem. The present study aims to survey the phenotypic and genotypic characteristics of carbapenem-resistant Escherichia coli isolates collected from hospitalized patients and outpatients ...
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Background & Objective: Carbapenem-resistant is Gram-negative bacteria representing a worldwide public health problem. The present study aims to survey the phenotypic and genotypic characteristics of carbapenem-resistant Escherichia coli isolates collected from hospitalized patients and outpatients in Ardabil province, Iran.Methods: Two hundred samples were collected from the patients who had already been referred to the hospitals in Ardabil, Iran, from January to June 2017. Each patient's social and demographic data were recorded in the first step. The resistance profile of all E. coli isolates against imipenem and meropenem antibiotics were determined using the Kirby-Bauer disk diffusion method. Moreover, the broth microdilution method determined the Minimum Inhibitory Concentration (MIC) of E. coli isolates to imipenem. The Carbapenem Inactivation Method (CIM) and Carba NP test were employed for screening carbapenem-resistant strains. The frequency of carbapenem-encoding genes was determined using Polymerase Chain Reaction (PCR) method. The Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR analysis was used to evaluate the genetic relatedness of E. coli isolates.Results: Out of 200 urine samples, 66% (n = 132) of the samples were collected from women. The patients' age varied from 1 month to 93 years. Results of the disk diffusion method revealed that 33% (n=66/200) of E. coli isolates were resistant to imipenem. However, imipenem resistance was detected in 37% (n = 74/200) of the E. coli isolates using broth microdilution method. All E. coli isolates were negative in CIM and Carba NP tests. Moreover, we could not detect any carbapenemase encoding genes among E. coli isolates. The ERIC-PCR method revealed the E. coli strains were classified into 39 clusters with 80% similarity.Conclusion: It appears that E. coli is the most common cause of urinary tract infection in Ardabil province.
Behnam Mohammadi-Ghalehbin; Shahram Habibzadeh; Mohsen Arzanlou; Roghayeh Teimourpour; Saeideh Amani Ghayum
Abstract
Background & objective: Pneumocystis pneumonia (PCP) is responsible for pulmonary infection in immunocompromised patients. This study aimed to investigating the frequency of Pneumocystis colonization in patients hospitalized in the intensive care unit (ICU) and evaluating the relationship between ...
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Background & objective: Pneumocystis pneumonia (PCP) is responsible for pulmonary infection in immunocompromised patients. This study aimed to investigating the frequency of Pneumocystis colonization in patients hospitalized in the intensive care unit (ICU) and evaluating the relationship between PCP and Pneumocystis colonization. Methods: In the current cross sectional study bronchoalveolar lavage (BAL)fluids of 100 patients were collected from surgery and neurosurgery ICUs with different underlying corticosteroid therapy conditions. Patients were divided into 2 groups (patients who received corticosteroids and not received corticosteroids). Direct examination on BAL fluids was performed by the Gomori methenamine silver andGiemsa staining techniques. Additionally, 2 filtered air samples of the 2 above mentioned units were collected. A nested-PCR targeted mtLSUrRNA gene and sequencing were used to identify Pneumocystis spp. Results: In direct microscopy, 31 out of 100 hospitalized patients (31%) showed positive results. Twenty-three (46%) of smear positive patients were from the group of patients who received corticosteroid, the other 8(16%) were from the group of patients who didn’t receive corticosteroids (P= 0.001). Pneumocystis jirovecii DNA was detected in 77 out of 100 BAL samples by nested-PCR (77%) in which 40(52%) and 37(48%) samples were obtained from the patients who received and not received corticosteroids, respectively. Pneumocystis genome was found in 1 of the 2 filtered air samples. Conclusion: A significant number of patients who received corticosteroids were also colonized by P. jirovecii that may predispose to PCP or be transmitted to susceptible patients. A significant relationship was observed between the mean hospital stay and detection rate.
