Microbiology
Mehrdad Gholami; Mohammadreza Haghshenas; Mona Moshiri; Shbnam Razavi; Abazar Pournajaf; Gholamreza Irajian; Mohsen Heidary
Abstract
Background & objective: Multidrug-resistant Acinetobacter baumannii (MDR-AB) is an important nosocomial pathogen which is associated with significant morbidity and mortality, particularly in high-risk populations. Aminoglycoside-modifying enzymes (AMEs) and 16S ribosomal RNA (16S rRNA) ...
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Background & objective: Multidrug-resistant Acinetobacter baumannii (MDR-AB) is an important nosocomial pathogen which is associated with significant morbidity and mortality, particularly in high-risk populations. Aminoglycoside-modifying enzymes (AMEs) and 16S ribosomal RNA (16S rRNA) methylation are two important mechanisms of resistance to aminoglycosides. The aim of this study was to determine the prevalence of 16S rRNA methylase (armA, rmtA, rmtB, rmtC, and rmtD), and the AME genes [aac(6′)-Ib, aac(3)-I, ant(3′′)-I, aph(3′)-I and aac(6')-Id], among clinical isolates of A. baumannii in Tehran, Iran. Methods: Between November 2015 to July 2016, a total of 110 clinical strains of A. baumannii were isolated from patients in two teaching hospitals in Tehran, Iran. Antimicrobial susceptibility testing was performed according to Clinical and Laboratory Standards Institute guidelines. The presence of genes encoding the AMEs and16S rRNA methylases responsible for resistance was investigated by multiplex polymerase chain reaction. Results: The results showed that colistin was an effective antibiotic and could be used as a last-resort treatment of infections caused by MDR-AB. The resistance rate to aminoglycosides were 100%, 96.36% and 90.9% for tobramycin, gentamicin and amikacin, respectively. In this study, AME genes of aac(6′)-Ib, aac(3)-I and ant(3′′)-I were most prevalent among the isolated strains. Conclusion Markedly high resistance to tobramycin, gentamicin and amikacin was noted in current study. Our results suggested that modifying enzyme genes in conjunction with methylation of 16S rRNA might contribute to aminoglycoside resistance induced in vivo in A. baumannii.Further studies are required to determine the prevalence of the aminoglycoside resistance genes in other hospitals of Iran.
Microbiology
Faramarz Masjedian Jazi; Gholamreza Irajian; Reza Mirnejad; Vahhab Piranfar; Taghi zahraei salehi; Noor Amir Mozafari; Ehsanollah Ghaznavi-rad; Mahmoud Khormali
Volume 11, Issue 3 , July 2016, , Pages 238-247
Abstract
Background: Brucellosis is an endemic zoonotic disease in the Middle East. This study intended to design a uniplex PCR assay for the detection and differentiation of Brucella at the species level and determining the antibiotic susceptibility pattern of Brucella in Iran. Methods: Sixty-eight Brucella ...
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Background: Brucellosis is an endemic zoonotic disease in the Middle East. This study intended to design a uniplex PCR assay for the detection and differentiation of Brucella at the species level and determining the antibiotic susceptibility pattern of Brucella in Iran. Methods: Sixty-eight Brucella specimens (38 animal and 30 human specimens) were analyzed using PCR (using one pair of primers). Antibiotic susceptibility patterns were evaluated and compared using the E-Test and disk diffusion susceptibility test. Tigecycline susceptibility pattern was compared with other antibiotics. Results: Thirty six isolates of B. melitensis, 2 isolates of B. abortus and 1 isolate of B. suis from the 38 animal specimens, 24 isolates of B. melitensis and 6 isolates of B. abortus from the 30 human specimens were differentiated. The MIC50 values of doxycycline for human and animal specimens were 125 and 10 μg/ml, respectively, tigecycline 0.064 μg/ml for human specimens and 0.125μg/ml for animal specimens, and trimethoprim/ sulfamethoxazole and ciprofloxacin 0.065 and 0.125μg/ml, respectively, for both human and animal specimens. The highest MIC50 value of streptomycin in the human specimens was 0.5μg/ml and 1μg/ml for the animal specimens. The greatest resistance shown was to tetracycline and gentamicin, respectively. Conclusion: Uniplex PCR for the detection and differentiation of Brucella at the strain level is faster and less expensive than multiplex PCR, and the antibiotics doxycycline, rifampin, trimethoprim-sulfamethoxazole, ciprofloxacin, and ofloxacin are the most effective antibiotics for treating brucellosis. Resistance to tigecycline is increasing, and we recommend that it be used in a combination regimen.
Microbiology
Gholamreza Irajian; Mehri Sharifi; Shiva Mirkalantari; Reza Mirnejad; Mohammad reza Jalali Nadoushan
Volume 11, Issue 2 , April 2016, , Pages 138-143
Abstract
Background: In most cases, prostatitis can be caused by a bacterial agent such as Ureaplasma urealyticum. Considering to the cumbersome of the culture method for the detection of Ureaplasma species in clinical samples such as prostate; PCR method that is faster and more appropriate than the cultivation ...
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Background: In most cases, prostatitis can be caused by a bacterial agent such as Ureaplasma urealyticum. Considering to the cumbersome of the culture method for the detection of Ureaplasma species in clinical samples such as prostate; PCR method that is faster and more appropriate than the cultivation methods, can be utilized for the detection of U. urealyticum and U. parvum. PCR-RFLP method can differentiate both biovars and assist in studies of the clinical diagnosis, epidemiology and pathology of this species in human. The aim of this study was to molecular detection of U. urealyticumin in prostate tissue samples based on PCR- RFLP. Methods:Two hundred prostate tissue samples were collected from patient suffering from prostatitis. The PCR assay was used to amplify a 559 bp fragment of 16S-23SRNA interspace region of Ureaplasma. After sequencing, PCR products from positive samples were digested with TaqI restriction enzyme. Results: Seven cases (3.5%) out of 200 prostate tissue samples were positive for U. urealyticum. Results of PCR products sequencing demonstrated that all isolates were U. parvum biovar. PCR-RFLP results shown that there was not any differentiation in pattern of enzymatic digestion, in addition, all isolates were U. parvum, serovar 3. Conclusion: U. urealyticum can be one of the causing agents of prostatitis. Using PCR-RFLP with specific primer and restriction enzyme is a rapid and cost-effect method for detection and differentiation of Ureaplasma from clinical samples.
Masoume Bina; Abazar Pournajaf; Shiva Mirkalantari; Malihe Talebi; Gholamreza Irajian
Abstract
Background and Objective: The production of carbapenemases especially Klebsiella pneumoniae carbapenemase (KPC) is the most important mechanism of enzymatic resistance in isolated Enterobacteriaceae such as K. pneumoniae. The purpose of this study was detected of the carbapenemase producer K. pneumoniae ...
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Background and Objective: The production of carbapenemases especially Klebsiella pneumoniae carbapenemase (KPC) is the most important mechanism of enzymatic resistance in isolated Enterobacteriaceae such as K. pneumoniae. The purpose of this study was detected of the carbapenemase producer K. pneumoniae strains with phenotypic and genotypic methods. Method: Out of 800 strains, 270 K. pneumoniae strains (33.7%), were obtained. Antibiotic susceptibility test was performed by disk diffusion method in accordance with CLSI guidelines. Carbapenem resistant strains were identified by the Modified Hodge Test based on CLSI instruction and PCR for surveying the presence of bla-KPC gene. Results: A total 270 K. pneumoniae strains were collected. Antibiotic susceptibility test results showed the highest and lowest resistance was related to piperacillin (60.6%) and carbapenems (14.6%) respectively. 80.5% (33 of 41) isolates were positive by MHT, but all of them (100%) were negative for amplification of the bla-KPC gene in the PCR method. Conclusion: The MHT was an appropriate method for approving carbapenemase production. Moreover, a laboratory could accept the carbapenemase production with PCR method for the bla-KPC gene, which has the additional profit of validating which KPC is present. How to cite this article: Bina M, Pournajaf A, Mirkalantari S, Talebi M, Irajian G. Detection of the Klebsiella pneumoniae carbapenemase (KPC) in K. pneumoniae Isolated from the Clinical Samples by the Phenotypic and Genotypic Methods. Iran J Pathol. 2015;10(3):199-205.
Alireza Nateghian; Gholamreza Irajian; Fatemeh Faraji
Volume 6, Issue 2 , April 2011, , Pages 79-85
Abstract
Background and Objectives: The aim of the study was to determine the role and characteristics of nosocomial and community acquired Staphylococcus sepsis in admitted children in tertiary centers in Iran. Patients and Methods: A cross sectional descriptive-analytic study was performed since March ...
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Background and Objectives: The aim of the study was to determine the role and characteristics of nosocomial and community acquired Staphylococcus sepsis in admitted children in tertiary centers in Iran. Patients and Methods: A cross sectional descriptive-analytic study was performed since March 2008 to March 2009 in which all blood cultures from various admitted patients were checked for Staphylococcu aurues in Aliasghar Children Hospital, Tehran, Iran. Upon diagnosis by appropriate microbiologic tests, antimicrobial testing was done according to CLSI methods. Results: Overall, 2647 blood culture samples from 5197 admitted children were sent from which, 25 cases of S. aurues septicemia were isolated; the rate was 4.8 in 1000 admissions;1.3 in 1000 admissions were nosocomial and 3.5 in 1000 admissions were community acquired sepsis. Ten cases were neonates and remainder was older. Eighteen cases were CA and 28% were NI septicemia with mean age of 38.8 months and 8.2 months, respectively. Mean duration of admission in NI group was 20.5 days, however it was 12.6 days in CA group; they also had higher mortality rate. Conclusion: The rate of Staphylococcus sepsis in this study was higher than developed countries for both CA and NI cases, both groups had high rate of resistance. Although most cases were CA in which significant proportion had underlying malignancy, NI group had a longer duration of admission and mortality.
Ali Jazayeri Moghadas; Gholamreza Irajian
Volume 4, Issue 3 , June 2009, , Pages 105-108
Abstract
Background and Objectives: Urinary tract infection is one of the most common bacterial infections in the human population, and more frequent infection during pregnancy. With notice to this point that most of urinary tract infections during pregnancy are asymptomatic, they could lead to serious ...
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Background and Objectives: Urinary tract infection is one of the most common bacterial infections in the human population, and more frequent infection during pregnancy. With notice to this point that most of urinary tract infections during pregnancy are asymptomatic, they could lead to serious complications such as prematurity, low-birth weight, hypertension, and higher fetal mortality rates ifuntreated. This study was aimed to determine the prevalence of asymptomatic bacteriuria, bacterial agents and their antibiotic susceptibility pattern in pregnant womenattendingSemnan public health centers during 2007-8. Patients and Methods: In this descriptive cross sectional study,pregnant women attending Semnan public health centers during May 2007 and June 2008 were investigated. Clean catch mid stream urine samples were collected and cultured on Eosin Metylene Blue agar and Blood agar by calibrated loop method. Suspected colonies were identified, antibiotic susceptibility test was done. Results: Of 297 samples, 10 (3.3%) were positive for asymptomatic urinary tract infection. The dominant bacterial isolate was Escherichia coli (70%). The antibiotic susceptibility was observed to ciprofloxacin, ceftazidime and cefotaxime (80%), the most resistance was amoxicillin- clavulanic acid (90%). Conclusion: Frequency of asymptomatic UTI in pregnant women in this study is significantly lower than similar studies. Antibiotic susceptibility rate to using antibiotics do not show significant differences with most other studies.
Ali Jazayeri Moghadas; Gholamreza Irajian; Reza Ranjbar
Volume 4, Issue 3 , June 2009, , Pages 128-132
Abstract
Background: and Objectives: Salmonella infections are endemic in many developing countries with poor sanitary conditions, but emerge sporadically as a serious public health threat in developed countries. Infections with multidrug resistant (MDR) strains of Salmonella have been associated with ...
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Background: and Objectives: Salmonella infections are endemic in many developing countries with poor sanitary conditions, but emerge sporadically as a serious public health threat in developed countries. Infections with multidrug resistant (MDR) strains of Salmonella have been associated with treatment failures. Salmonella spp. resistant to extended spectrum cephalosporins are increasing in prevalence worldwide. The aim of this study was to determine the antimicrobial susceptibility, multidrug resistance and extended spectrum beta lactamase (ESBL) production among clinical isolates of Salmonella spp. during 2007 in Tehran, Iran. Patients and Methods: In this cross-sectional study, fifty Salmonella spp. were identified by API 20E system and serotyped by the slide agglutination test. Disk diffusion test was performed. Double disk synergy test was used as a screening test for ESBL production, using disks of cefotaxime and ceftazidime with and without clavulanic acid. Results: From 50 Salmonella spp. 12 (24%) were S. enterica serotype paratyphi B, 24 (48%) S. enterica serotype paratyphi C and 14 (28%) were S. enterica serotype Typhi. The most susceptibility and resistance were observed to ceftazidime (98%) and amoxicillin-clavulanic acid (96%), respectively. 28(56%) were resistant to 5 or more antibiotics. ESBL production was detected by double disk synergy test in one isolate (2%). Conclusion: Results showed increase in antibiotic and multidrug resistance pattern of Salmonella spp. comparing to previous studies in Iran and other countries.It seems that this is the first report of Salmonella spp. ESBL producing in Iran.
Farahnaz Bineshian; Gholamreza Irajian; Seyed Kaveh Koochak-Alavi; Mohammad Reza Fredonian
Volume 1, Issue 4 , September 2006, , Pages 141-144
Abstract
Background and Objective: Otitis externa is a common condition affecting the external auditory canal. Predisposing factors implicated in the pathogenesis of the condition include preexisting aural disease, genetic factors, infection, trauma, and climatic conditions. Bacteria are the most common cause ...
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Background and Objective: Otitis externa is a common condition affecting the external auditory canal. Predisposing factors implicated in the pathogenesis of the condition include preexisting aural disease, genetic factors, infection, trauma, and climatic conditions. Bacteria are the most common cause of infection and fungi play a smaller but significant role in the disease. Otomycosis is characterized by inflammation, pruritus, pain, and scaling, usually in a unilateral pattern. Otomycosis has a worldwide distribution with a higher prevalence in the hot, humid, and dusty climate of the tropical and subtropical regions. The objectives of this study were to determine the prevalence of mycotic infections in inflammatory conditions of the ear and to determine fungal species responsible for otitis. Materials and Methods: The study was conducted on 70 cases who presented with symptoms of otitis from September 2000 to December 2003. Patients were admitted in ENT clinic of Amir- Al-Momenin hospital. To determine the species of fungi present in the ears, samples were collected from the external auditory meatus using sterile swabs for mycological examination. These specimens were processed at the department of microbiology. A part of the samples was used for direct microscopy in 10% potassium hydroxide and Gram’s method was employed to stain the smears from all specimens cultured on Sabouraud Dextrose agar with chloramphenicol (Sc). To identify yeasts, assimilation tests were used by API 20C AUX. Results: Otomycosis was diagnosed in 8 (11. 4%) of 70 investigated patients. Yeast species responsible for otitis were classified as belonging to the genus Candida. The most frequent fungal species detected were Candida parapsilosis (5 cases), Candida glabrata (2 cases), Candida.krusei (1 case). In other patients, the bacterial agents isolated were as follow as: Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus, S. epidermidis, S. saprophyticus, and Enterobacteriaceae. Conclusion: In the present study fungi on average were the etiological factor of otomycosis in 11.4% of cases. A similar rate for ear fungal infections was observed by Kurnatowski and Filipiak. In order to solve the therapeutic difficulties and to apply the most adequate treatment, comprehensive mycological examinations, often avoided during routine clinical procedures, must be performed. Underestimation and sometimes ignorance of the role of these pathogens in the etiology of diseases of the ear may lead to a prolonged and/or ineffective treatment of patients.