Masoud Marashifard | Yasuj University of Medical Sciences (original) (raw)

Papers by Masoud Marashifard

Background and Objective: Pseudomonas aeruginosa is an opportunistic pathogen causing nosocomial ... more Background and Objective: Pseudomonas aeruginosa is an opportunistic pathogen causing nosocomial burn infections. Disease results from the production ofnumerous virulence factors, some of which are injected directly into the eukaryotic host cells via the type III secretion system (T3SS).The aim of this study was to determine the prevalence of cytotoxins encoding exoT, exoY, exoS and exoU genes among the P. aeruginosa isolated from burn patients. Materials and Methods: Over one year periodof study, a total of 95 isolates of P. aeruginosa were collected and identified from burn infections in hospitalized patients. Polymerase chain reaction (PCR)-based method was used for detection of exoT, exoYexoSand exoU genes. According to CLSI (Clinical Laboratory Standards Institute) guidelines antimicrobial susceptibility testing was performed by disc diffusion method against 10 antibiotics. The data were analyzed by÷ 2 test. A p value of <0.05 was considered as statistically significant Results: All of the isolates of P. aeruginosa contained exoT gene while exoY gene was detected in 69.5 % of isolates. The prevalence of exoU and exoS genes was 44.1% and 35.8%, respectively. 8.42% of isolates harbored all of the four genes. Coexistence of exoS and exoU was seen in 10.5% of the isolates. High resistance rates were seen for cefipime, Azteronam and Ofloxacin. Conclusion: Considering the low prevalence of exoS in P. aeruginosa causing burn infection in comparison with other infections caused by this bacterium, it seems that this gene has a minor role in the P. aeruginosa pathogenesis isolated from burn infection. Instead, exoT and exoY were found in nearly all isolates and probably, these genes may have a greater role in burn infections.

Microbial pathogenesis, 2016

Staphylococcus aureus by producing biofilm and facilitating chronic infection is a common cause o... more Staphylococcus aureus by producing biofilm and facilitating chronic infection is a common cause of mastitis in cows and thereby can cause food poisoning by production of enterotoxins in milk. The agr typing method is an important tool for epidemiological investigation about S. aureus. The aims of the present study were to detect biofilm related genes, 5 classical enterotoxin genes and the agr types among S. aureus isolates. The ability of S. aureus isolates to produce biofilm was evaluated by modified CRA plate. Six biofilm related adhesion genes (icaD, icaA, fnbA, bap, clfA and cna), five classical enterotoxin genes (sea, seb, sec, sed and see) and tst-1 gene were detected by PCR methods. Multiplex-PCR was used to determination of the agr groups. 55 out of 80(68.8%) S. aureus isolates were biofilm producer. The icaD gene was detected in 70 (87.5%) of isolates. The prevalence rates of fnbA, icaA, clfA, cna and bap were 72.5, 56.25, 50, 22.5, and 5% respectively. The agr group I and ...

Objective(s): The aim of the present study was to determine the aminoglycoside modifying enzymes ... more Objective(s): The aim of the present study was to determine the aminoglycoside modifying enzymes (AMEs) encoded genes, tetracycline resistance genes, and the coa based typing of Staphylococcus aureus isolates in the Southwest of Iran. Materials and Methods: Antimicrobial susceptibility of isolates was carried out by agar disk diffusion methods. Two sets of multiplex PCR mixture were used for detection of AME genes and tet genes. All of the isolates were typed with the coagulase gene typing method. Of the 121 isolates, 29.75% and 47.93% were resistant to at least one aminoglycosides and tetracyclines, respectively. Results: The aac(6’)-Ie-aph(2”) was the most frequent gene (97.22%), and aph (3’)-IIIa and ant (4’)-Ia genes were detected in 61.11% and 11.11% of aminoglycoside resistant isolates, respectively. The tetK and tetM genes were detected in 82.75% and 56.9% of tetracycline resistant isolates, respectively. Overall 31.4% of isolates were MRSA. Totally 17 distinct coa gene RFLP ...

Background and purpose: Staphylococcus aureus is one of the most common nosocomial pathogens espe... more Background and purpose: Staphylococcus aureus is one of the most common nosocomial pathogens especially among burn patients. Aminoglycoside is usually used in combination with other antibiotics for treatment of serious S. aureus infections. Resistance to aminoglycoside antibiotics is one of the most important problems in treatment of S.aureus infections. The aim of the present study was to determine the frequency of aminoglycoside resistance genes in S. aureus isolated from burn patients. Materials and methods: A total of 81 isolates of S.aureus were collected from burn wounds of patients hospitalized in Taleghani hospital in Ahvaz, Iran. Conventional laboratory tests were used for identification of S. aureus at species level and then confirmed by detection of nucA gene. Antimicrobial susceptibility pattern was tested against 11 different antibiotics by Disc Agar Diffusion Method. Frequency of aminoglycoside resistance genes (aac(6’)-Ie-aph(2’’)-I, aph(3’)-IIIa, and ant(4’)-Ia) were...

Background: Neonatal sepsis is a serious worldwide problem causing significant rates of mortality... more Background: Neonatal sepsis is a serious worldwide problem causing significant rates of mortality and morbidity in newborns, especially in cases with delayed infection diagnosis and management. The present study aimed to evaluate the bacteriological profiles, antibiotic susceptibility patterns, risk factors, clinical manifestations, and laboratory findings in neonatal sepsis in southwest of Iran. Methods: In this descriptive-analytic study, 342 neonates with suspected sepsis admitted to the neonatal ward and NICU were included. Using standard protocols, blood samples were transported to the BACTEC blood culture system. Then, conventional biochemical tests were used for the identification of bacterial genera and species. The bacterial antimicrobial susceptibility patterns were determined usingagardisk diffusion method according to the CLSI guidelines. Demographic data, clinical findings, risk factors, mortality rates, and laboratory parameters were collected for each patient. Results...

Molecular Genetics, Microbiology and Virology

Abstract The emergence of multidrug (MDR) isolates of Escherichia coli has made the treatment of ... more Abstract The emergence of multidrug (MDR) isolates of Escherichia coli has made the treatment of urinary tract infections (UTI) very challenging. Integrons are considered to be one of the most important mechanisms in the dissemination of resistance genes. In the current study, we sought to investigate the antibiotic resistance patterns, class 1–3 integrons and corresponding gene cassettes in urinary isolates of E. coli in the southwest of Iran. A total of 144 E. coli isolates were collected from the patients with UTIs. Antibiotic susceptibility test conducted by the disc diffusion method using 12 different antibiotics. The polymerase chain reaction (PCR) was used for the detection of intl1 , intI2 , and intI3 genes. To analyze the gene cassettes, variable regions of class 1 integron were amplified by PCR and subjected to sequencing. The highest rates of resistance were exhibited to amoxicillin/clavulanic (73.6%), trimethoprim-sulfamethoxazole (63.9%) and tetracycline (63.2%). Totally, intI1 and intI2 genes were identified in 62.5 and 9% of isolates. One-hundred and nine (75.7%) E. coli isolates were multidrug resistance (MDR), among which 78% harbored intI1 gene. Also, all of the intI2 positive E. coli isolates were MDR. Ten different gene cassette arrays were found in intl1 positive E. coli including dfrA5 , dfrA25 , dfrA7 , aacA4 , aadA1 , aadB-catB3 , dfrA17-aadA5 , dfrA12-orfF-aadA2 , aadA1-bla OXA-30 , and dfrA5-catB3-aacA4. The dfrA17-aadA5 was the most prominent gene cassette array among E. coli isolates. Characterization of resistance gene cassettes located in integrons in this study showed a high frequency of dfrA and aad genes which confer resistance to trimethoprim and aminoglycosides. The obtained result from this study could be useful in planning to prevent the rising rate of antibiotic resistance.

Parasites & Vectors

Background Trichostrongylus is one of the most important zoonotic trichostrongylid nematodes, inf... more Background Trichostrongylus is one of the most important zoonotic trichostrongylid nematodes, infecting mostly livestock. Data on its genetic characteristics are lacking in Iran. Methods We determined the phylogenetic relationships of Trichostrongylus species in three counties of Kohgiloyeh and Boyerahmad (K-B) province, southwest Iran. Small intestine and abomasum of 70 sheep and goats were investigated. Results A total of 35 isolates of Trichostrongylus worms were detected and all were genetically identified as Trichostrongylus vitrinus. Analysis of 321 bp of the internal transcribed spacer 2 (ITS2) of ribosomal DNA revealed 16 genotypes. All genotypes were single nucleotide polymorphisms, including some hypervariable points. All sequences were trimmed to 170 bp, compared with sequences on GenBank including short sequences from other endemic foci of Iran and other countries and all isolates were used to generate a maximum likelihood phylogenetic tree, which consisted of two clades...

BioMed Research International

Iran is one of the six countries with the most cutaneous leishmaniasis (CL) patients. Understandi... more Iran is one of the six countries with the most cutaneous leishmaniasis (CL) patients. Understanding better the genotypes of the parasite population in relation to geography and climate is critical to achieving better CL control. We aimed to characterise the population structure ofLeishmania tropica, the cause of anthroponotic cutaneous leishmaniasis (ACL), from important foci in southeast (Bam and Kerman) and southwest (Shiraz) Iran. A total of 39L. tropicaisolates from ACL patients from southeast (Bam 14, Kerman 12) and southwest (Shiraz 13) Iran were analysed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) of the kinetoplast DNA (kDNA) using restriction enzymesMspI (HpaII) andClaI. 37 genotypes were identified among south IranL. tropicaisolates. The unweighted pair group method with arithmetic mean (UPGMA) tree obtained from the banding patterns ofClaI digested kDNA RFLP distinguished southeast from and southwestL. tropicaisolates with some subclus...

Tropical Animal Health and Production

Journal of Global Antimicrobial Resistance

OBJECTIVES Fluoroquinolones (FQs) are recommended as the drugs of choice for the empirical treatm... more OBJECTIVES Fluoroquinolones (FQs) are recommended as the drugs of choice for the empirical treatment of urinary tract infections (UTIs). This study investigated the molecular determinants of FQ resistance in Escherichia coli and Klebsiella pneumoniae isolates in Iran. METHODS A total of 364 clinical isolates of E. coli (n=144) and K. pneumoniae (n=220) were collected from patients with UTI. Susceptibility of the isolates to ciprofloxacin, levofloxacin, gatifloxacin and nalidixic acid was evaluated by disk diffusion. The presence of qnrA, qnrB and qnrS genes was assessed by PCR. Nucleotide sequences of the gyrA and parC genes were determined. RESULTS Eighty-seven (60.4%) and 15 (6.8%) E. coli and K. pneumoniae isolates, respectively, were resistant to at least one of the tested FQs. Plasmid-mediated quinolone resistance (PMQR) genes were detected in 12.6% and 60.0% of FQ-resistant E. coli and K. pneumoniae, respectively. Whilst qnrB predominated in K. pneumoniae, qnrS was the most prevalent PMQR gene in E. coli. S83L (98.9%) and D87N (59.8%) were the most frequent mutations identified in GyrA of E. coli, and 55.2% (n=48) of FQ-resistant E. coli isolates had mutation in ParC harbouring S80I and E84V substitutions. The GyrAS83L substitution was found in only one FQ-resistant K. pneumoniae isolate. CONCLUSIONS FQ resistance was much more common in E. coli isolates than in K. pneumoniae. Whilst mutations in the drug target-encoding genes gyrA and parC were the major mechanisms involved in FQ resistance in E. coli, PMQR determinants commonly mediated FQ resistance in K. pneumoniae.

Microbial pathogenesis, Jan 5, 2016

Staphylococcus aureus remains a major cause of nosocomial infection worldwide. Characterization o... more Staphylococcus aureus remains a major cause of nosocomial infection worldwide. Characterization of S. aureus isolates circulating in the southwest of Iran will contribute to understand and control the spread of the strains in this area. spa and SCCmec typing methods were used for genotyping of 125 S. aureus isolates obtained from two teaching hospitals in Ahvaz. Drug susceptibility testing was performed by using disk diffusion method. Frequency of the methicillin resistant S. aureus (MRSA) isolates was 39% (n = 34) and 27% (n = 10) in Emam Khomeini and Golestan hospitals, respectively. Except for Erythromycin, MRSA strains showed high rate of resistance to antimicrobial agents including penicillin (100%), norfloxacine (80%), azitromycin (80%), ciprofloxacin (80%), gentamycin (77%), cotrimoxazole (75%), cephotaxime. All isolates were sensitive to vancomycin. Out of 44 MRSA strains, 39 (88.5%) were SCCmec III, three (7%) were IVc and two (4.5%) of them were nontypeable. spa types t037...

Avicenna Journal of Medical Biotechnology, 2020

Background: Growing antibiotic resistance among urinary opportunistic pathogens such as Klebsiell... more Background: Growing antibiotic resistance among urinary opportunistic pathogens such as Klebsiella pneumoniae (K. pneumonia) has created a worrisome condition in the treatment of the Urinary Tract Infections (UTIs) in recent years. Integrons play a significant role in the dissemination of antibiotic resistance genes. The present study was conducted to investigate class 1–3 integrons and the corresponding resistance gene cassettes in urinary K. pneumoniae isolates. Methods: In this study, from December 2015 to September 2016, a total of 196 K. pneumoniae isolates were collected from the patients with UTI referred to medical diagnostic laboratories in Yasouj, Southwestern Iran. Antibiotic susceptibility patterns of isolates were determined using 12 antibiotics by the disc diffusion method. Polymerase Chain Reaction (PCR) was used for detection of integron genes (intI1, intI2, and intI3). The variable regions of integrons were amplified by PCR and sequenced to identify the correspondin...

APMIS, 2015

Methicilin resistance Staphylococcus aureus (MRSA) infections are the major challenges in hospita... more Methicilin resistance Staphylococcus aureus (MRSA) infections are the major challenges in hospitals, especially in the burn units. The use of molecular typing methods is essential for tracking the spread of S. aureus infection and epidemiological investigations. The aim of this study was to find the profile of the spa types and also the prevalence of each SCCmec type of S. aureus strains in a central burn hospital in southwest of Iran. A total of 81 non-duplicate S. aureus were isolated from burn patients between April 2011 and February 2012. The susceptibility of the isolates against 13 different antibiotics was tested by disk agar diffusion (DAD) method. MRSA strains were identified by amplification of mecA gene. Multiplex-polymerase chain reaction (PCR) technique was used to determine the SCCmec types of MRSA strains and all the S. aureus isolates were typed by spa typing method. Detection of mecA gene showed that 70 (86.4%) of the isolates were MRSA. The highest rate of resistance was observed for penicillin (97.5%) and erythromycin (77.8%). None of the isolates were resistant to vancomycin. Sixty-seven of the 70 MRSA isolates harbored only SCCmec type III and three untypeable isolates. Five different spa types were detected. The most common spa types were t037 (42.5%) and t631 (34.5%) and were only found in MRSA isolates. Only SCCmec type III was found in burn patients which emphasizes the HA-MRSA origin of these strains. Only five different spa types identified in this study are in accordance with one SCCmec type which indicates that a limited number of bacterial colons are circulated in the burn unit in this hospital.