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Spread of methicillin-resistant Staphylococcus aureus (MRSA) isolates is a worldwide problem. Molecular typing is a useful tool to understand MRSA epidemiology. Herein, we determined vancomycin-resistant, SCCmec and spa types among MRSA isolates recovered from healthcare and community-acquired infections in Kerman, Iran. A total of 170 S. aureus isolates were collected from different patients who were admitted to affiliated hospitals of Kerman University of Medical science. MRSA and vancomycin-resistant S. aureus (VRSA) isolates were detected by phenotypic methods. Polymerase chain reaction (PCR) technique was used for detection of mecA, vanA and vanB genes. Staphylococcal cassette chromosomemec (SCCmec) and spa typing were used for molecular typing of among MRSA isolates. Overall, 53% of isolates were considered as MRSA. Two MRSA isolates were resistant to vancomycin and vanA was detected in only one of VRSA isolates. SCCmec type III belonged to spa types t030 and t459 which they were the dominant spa types among community-associated MRSA (CA-MRSA) and healthcare-acquired MRSA (HA-MRSA) isolates. Our findings showed that the SCCmec type I and III spread from hospital settings to community, although the SCCmec type IV spread from community to healthcare systems. We have also reported VRSA isolates from hospitalized patients, therefore, appropriate policies should be enforced in order to prevent the spread of antibiotic resistance isolates in hospitals settings.

Background and Objectives: The new beta-coronavirus, which caused Severe Acute Respiratory Coronavirus-2 Syndrome (SARS-CoV-2), a major respiratory outbreak in Wuhan, China in December 2019, is now prevalent in many countries around the world. Identifying PCR-based viruses is a well-known and relatively stable protocol. Unfortunately, the high mutation rates may lead to widespread changes in viral nucleic acid sequences, and so using specific primers for PCR can be recom- mended. In this study, we evaluated the power of a conventional RT-PCR to detect SARS-CoV-2 RNA among the five set primer sets. Materials and Methods: The five genomic regions of the Coronavirus SARS-2 virus including Nucleocapsids (N), Enve- lope (E), RNA depended RNA Polymerase (RdRp), ORF1ab and Spike (S) were selected for primer designing. A convention- al RT-PCR was performed to compare sensitivity, specificity and other analytical characteristics of primers designed against two Real Time PCR commercial kits. Results: The result of the comparative analysis showed that the ORF1ab, N and RdRp primers had a sensitivity, specificity and positive predictive value higher than other primers. A significant difference in the analytical sensitivity between the studied primer sets in RT-PCR kits was observed. Conclusion: In this study, the ORF1ab, Nucleocapsid and RdRp regions have the best primers for identifying the SARS- CoV-2 RNA between different genes that have been suggested.

Background:Extended spectrum β-lactamases (ESBLs) and AmpC β-lactamases enzyme are major sources of resistance to β-lactam antibiotics especially in Enterobacteriaceae such as Escherichia coli and Klebsiella pneumoniae. Increasing frequency of the co-existence of ESBLs with AmpC-β-lactamases in bacteria is a serious threat for treating bacterial infections.Objectives:The aim of this study was to determine the presence of AmpC and CTX-M types of β-lactamases in clinical isolates of E. coli and K. pneumoniae producing ESBLs.Materials and Methods:Resistance to different antibiotics was determined using the standard disk diffusion method. ESBLs, MBLs and AmpC-β-lactamases were detected by the combination double disk test (CDDT) method and polymerase chain reaction (PCR) was used to determine blaCTX-M genes in the ESBLs and AmpC positive isolates.Results:The prevalence of ESBLs and AmpC-β-lactamase producer isolates was 181 (43.8%) and 133 (37.2%), respectively. The prevalence of blaCTX-M among isolates was 61 (14.7%).Conclusions:Outbreak of isolates co-expressing AmpC-β-lactamases and ESBLs can cause serious problems in the future, regarding the treatment of infections caused by these common enteric pathogens.

Background: Escherichia coli is the main causative pathogen in urinary tract infections (UTIs). Antibiotic resistance in this bacterium is an important problem in public health. Objectives: The aim of this study was to identify the blaTEM, blaSHV, blaOXA, and blaPER genes and AmpC-β-lactamase in clinical isolates of E. coli recovered from patients with UTIs in Kerman, Iran. Methods: E. coli isolates (N = 105) were analyzed for their antibiotic susceptibility with the disk diffusion method. ESBL and AmpCproducing isolates were detected using phenotypic methods. PCR was used to identify the blaTEM, blaSHV, blaOXA and blaPER genes in ESBL and AmpC-positive isolates. Results: More than 50% of the isolates were multi-drug resistant. The prevalence of ESBLs, AmpC-β-lactamase, blaTEM and blaOXA in the inpatient isolates was 37.2%, 2%, 37.2% and 5.8%, respectively. Further, the prevalence of ESBLs, blaTEM, blaSHV and blaOXA in the outpatient isolates was 42.5%, 24%, 5.5% and 1.8%, respectively. Conclusions: The prevalence of ESBL-producing E. coli strains in the community (outpatients) is higher than that in inpatients in Kerman, Iran. An outbreak of ESBL-producing isolates in the community can be a serious problem for public health, as resistance to other classes of antibiotics such as aminoglycoside and fluoroquinolones is often related with ESBL and AmpC production, therefore, detection of ESBL and AmpC-producing isolates in the community and hospitals is very important for the treatment and prevention of such isolates.

Background: The present study was conducted to investigate the distribution of virulence factors, capsular serotypes and antibiotic resistance properties of classical Klebsiella pneumoniae (cKP) and hypermucoviscous/hypervirulent Klebsiella pneumoniae (hvKP) isolated from different clinical specimens in Kerman, south-east of Iran. Materials and Methods: A total of 146 K. pneumoniae isolates were obtained from different clinical specimens. HvKP isolates were identified using the string test. Genes of capsular serotypes K1, K2, K5, K20, K54 and K57 and virulence-associated genes, rmpA, kfu, fimH, mrkD, allS, iutA, magA, entB and ybtS were evaluated by PCR. Antimicrobial susceptibility was also determined using the disc diffusion method. Results: Out of 146 K. pneumoniae isolates, 22 (15.1%) were hvKP. More than half of the hvKP isolates, 13 (59.1%), belonged to non-K1, K2, K5, K20, K54, K57 serotypes. Out of 22 hvKP isolates, 3 and 3 had K1 and K2 serotypes respectively. Among all isolates, entB 140 (95.9%) and mrkD 138 (94.5%) were the most common virulence genes. RmpA, iutA and kfu were associated with hvKP isolates (P-value <0.05). However, no significant difference was found in fimH, allS, mrkD, entB and ybtS genes between hvKP and cKP strains. HvKP exhibited significantly lower resistance rates to all antimicrobial agents than cKP, except to trimethoprim-sulphamethoxazole and ampicillin (P-value <0.05). Conclusion:The frequency of hvKP was low, but overall, the prevalence of virulence-related genes was higher in hvKP than cKP. HvKP was not related to specific serotypes. Furthermore, hvKP isolates were more susceptible to antimicrobial agents compared to cKP isolates.

Enzymatic alteration of aminoglycosides by aminoglycoside-modifying enzymes (AMEs) is the major mechanism of resistance to aminoglycosides. The purpose of this study was to determine the frequency of AME genes, staphylococcal chromosomal cassette mec (SCCmec) types, and molecular analysis of the coagulase (coa) gene in Staphylococcus aureus strains isolated from clinical specimens. Totally, 102 S. aureus were tested by disk diffusion and microbroth dilution methods for susceptibility to aminoglycosides. AMEs genes and SCCmec types were determined by multiplex polymerase chain reaction (PCR). For polymorphism analysis, the 3' end region of the coa gene was amplified by PCR and the products were then subjected to restriction digestion with HaeIII enzyme. Of the 102 S. aureus, 42 (41.2%) were methicillin-resistant S. aureus (MRSA). Thirty-five (83%) of MRSA strains were resistant to kanamycin, 32 (76.2%) to tobramycin, 30 (71.4%) to gentamicin, 25 (59.5%) to amikacin, and 10 (23.8%) to netilmicin. The aac(6')-Ie-aph(2″) was the most frequent gene among MRSA isolates 19 (45.2%), followed by aph(3')-IIIa 8 (19%), ant(4')-Ia 6 (14.3%), and aph(2″)-Id 2 (4.8%). SCCmec types included type I 10 (23.8%), II 1 (2.4%), III 21 (50%), and IV 7 (16.7%). Three (7.2%) isolates were nontypeable. Digestion of the PCR products of the coa gene yielded 19 distinct restriction fragment length polymorphism patterns. In conclusion, given the alarming rate of resistance to aminoglycosides among MRSA, the monitoring of aminoglycoside resistance and AME genes should be performed to limit the spread of aminoglycoside resistance among MRSA isolates. Several variants of the coa gene were found in the studied isolates, although the majority of the MRSA isolates belonged to a limited number of coagulase types.

Molecular typing is an important tool for control and prevention of infection. A suitable molecular typing method for epidemiological investigation must be easy to perform, highly reproducible, inexpensive, rapid and easy to interpret. In this study, two molecular typing methods including the conventional PCR-sequencing method and high resolution melting (HRM) analysis were used for staphylococcal protein A (spa) typing of 30 Methicillin-resistant Staphylococcus aureus (MRSA) isolates recovered from clinical samples. Based on PCR-sequencing method results, 16 different spa types were identified among the 30 MRSA isolates. Among the 16 different spa types, 14 spa types separated by HRM method. Two spa types including t4718 and t2894 were not separated from each other. According to our results, spa typing based on HRM analysis method is very rapid, easy to perform and cost-effective, but this method must be standardized for different regions, spa types, and real-time machinery.