scholarly journals Several Virulence Factors of Multidrug-Resistant Staphylococcus aureus Isolates From Hospitalized Patients in Tehran

Author(s):  
Abdolmajid Ghasemian ◽  
Shahin Najar Peerayeh ◽  
Bita Bakhshi ◽  
Mohsen Mirzaee
2002 ◽  
Vol 46 (3) ◽  
pp. 879-881 ◽  
Author(s):  
Jan M. Bell ◽  
John D. Turnidge

ABSTRACT As part of the SENTRY antimicrobial surveillance program, we examined the prevalence rates, types, and antibiograms of oxacillin-resistant Staphylococcus aureus from hospitalized patients from 17 institutions in eight countries in Asia-Pacific and South Africa (APAC). From April 1998 to December 1999, a total of 1,711 isolates of S. aureus (814 from blood, 392 from the respiratory tract, 467 from skin and skin structures, and 38 from urine) were collected from hospitalized patients within the APAC region. Multidrug-resistant oxacillin-resistant S. aureus (MORSA) isolates, defined as strains with three or more resistances to drug classes other than β-lactams, were the most common type of oxacillin-resistant S. aureus (ORSA). They were the most frequently identified pathogen in wound infections and were common in bloodstream and lower respiratory tract infections. In all contributing institutions combined, more than 45% (range, 4 to 74%) of S. aureus isolates were oxacillin resistant, and in six institutions, this rate exceeded 60%. MORSA accounted for 91.2% of all oxacillin-resistant isolates. Distinct resistance patterns predominated at various sites within the APAC region, suggesting the local evolution of resistant clones. Non-multidrug-resistant strains were frequent in one part of Australia. No vancomycin-intermediate strains were detected, and no strains were resistant to linezolid or quinupristin-dalfopristin. MORSA strains are a very common cause of infection in hospitalized patients in the APAC region.


PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254519
Author(s):  
Min Lu ◽  
Jean-Marie Parel ◽  
Darlene Miller

Background Methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant (MDR) S. aureus strains are well recognized as posing substantial problems in treating ocular infections. S. aureus has a vast array of virulence factors, including superantigens and enterotoxins. Their interactions and ability to signal antibiotics resistance have not been explored. Objectives To predict the relationship between superantigens and methicillin and multidrug resistance among S. aureus ocular isolates. Methods We used a DNA microarray to characterize the enterotoxin and superantigen gene profiles of 98 S. aureus isolates collected from common ocular sources. The outcomes contained phenotypic and genotypic expressions of MRSA. We also included the MDR status as an outcome, categorized as resistance to three or more drugs, including oxacillin, penicillin, erythromycin, clindamycin, moxifloxacin, tetracycline, trimethoprim-sulfamethoxazole and gentamicin. We identified gene profiles that predicted each outcome through a classification analysis utilizing Random Forest machine learning techniques. Findings Our machine learning models predicted the outcomes accurately utilizing 67 enterotoxin and superantigen genes. Strong correlates predicting the genotypic expression of MRSA were enterotoxins A, D, J and R and superantigen-like proteins 1, 3, 7 and 10. Among these virulence factors, enterotoxin D and superantigen-like proteins 1, 5 and 10 were also significantly informative for predicting both MDR and MRSA in terms of phenotypic expression. Strong interactions were identified including enterotoxins A (entA) interacting with superantigen-like protein 1 (set6-var1_11), and enterotoxin D (entD) interacting with superantigen-like protein 5 (ssl05/set3_probe 1): MRSA and MDR S. aureus are associated with the presence of both entA and set6-var1_11, or both entD and ssl05/set3_probe 1, while the absence of these genes in pairs indicates non-multidrug-resistant and methicillin-susceptible S. aureus. Conclusions MRSA and MDR S. aureus show a different spectrum of ocular pathology than their non-resistant counterparts. When assessing the role of enterotoxins in predicting antibiotics resistance, it is critical to consider both main effects and interactions.


Author(s):  
Amit Karmakar ◽  
Parimal Dua ◽  
Chandradipa Ghosh

Staphylococcus aureusis opportunistic human as well as animal pathogen that causes a variety of diseases. A total of 100Staphylococcus aureusisolates were obtained from clinical samples derived from hospitalized patients. The presumptiveStaphylococcus aureusclinical isolates were identified phenotypically by different biochemical tests. Molecular identification was done by PCR using species specific 16S rRNA primer pairs and finally 100 isolates were found to be positive asStaphylococcus aureus. Screened isolates were further analyzed by several microbiological diagnostics tests including gelatin hydrolysis, protease, and lipase tests. It was found that 78%, 81%, and 51% isolates were positive for gelatin hydrolysis, protease, and lipase activities, respectively. Antibiogram analysis of isolatedStaphylococcus aureusstrains with respect to different antimicrobial agents revealed resistance pattern ranging from 57 to 96%. Our study also shows 70% strains to be MRSA, 54.3% as VRSA, and 54.3% as both MRSA and VRSA. All the identified isolates were subjected to detection ofmecA,nuc, andhlbgenes and 70%, 84%, and 40% were found to harbourmecA,nuc, andhlbgenes, respectively. The current investigation is highly important and informative for the high level multidrug resistantStaphylococcus aureusinfections inclusive also of methicillin and vancomycin.


2021 ◽  
Vol 12 ◽  
Author(s):  
Bahman Mirzaei ◽  
Ryhaneh Babaei ◽  
Habib Zeighami ◽  
Maryam Dadar ◽  
Ali Soltani

Since the 1960s, the frequency of methicillin-resistant Staphylococcus aureus as a recurrent cause of nosocomial infections has increased. Since multidrug-resistant Staphylococcus has overcome antimicrobial treatment, the development of putative vaccines based on virulence factors could be a great help in controlling the infections caused by bacteria and are actively being pursued in healthcare settings. This mini-review provides an overview of the recent progress in vaccine development, immunogenicity, and therapeutic features of some S. aureus macromolecules as putative vaccine candidates and their implications against human S. aureus-related infections. Based on the reviewed experiments, multivalent vaccines could prevent the promotion of the diseases caused by this bacterium and enhance the prevention chance of S. aureus infections.


2015 ◽  
Vol 1 (2) ◽  
pp. 27-31 ◽  
Author(s):  
Abdolmajid Ghasemian ◽  
Shahin Najar Peerayeh ◽  
Bita Bakhshi ◽  
Mohsen Mirzaee

Background: The biofilm production is an important phenomenon by bacteria such as Staphylococcus aureus that contribute to the multiple drug resistance. Moreover, biofilm formation by multidrug-resistant Staphylococcus aureus causes evading from immune responses. Objective: The aim of this study was to detect biofilm formation and presence of several related genes among multidrug-resistant (MDR) isolates of Staphylococcus aureus. Methods: This cross sectional study was conducted at a hospital in Tehran, Iran from July 2012 to January 2013. Patients admitted with the infections of the different sites of the body were selected as study population. Staphylococcus aureus isolates were collected from hospitalized patients and identified by conventional diagnostic tests. The multidrug-resistant MRSA isolates were detected by antibiotic susceptibility test. The phenotypic biofilm formation was detected by micro-titre tissue plate assay. The polymerase chain reaction (PCR) was performed to detect the mecA, Staphylococcal Cassette Chromosome mec (SCCmec) types, accessory gene regulatory (agr) genes, the icaADBC and several genes encoding staphylococcal surface proteins including clfAB, fnbAB, fib, eno, can, ebps and bbp genes with specific primers. Results: A total number of 209 Staphylococcus aureus were isolated of which 64 (30.6%) isolates were methicillin-resistant; among which 36(56.2%) isolates were MDR. These isolates were resistant to amoxicillin, tetracycline, ciprofloxacin, gentamicin, erythromycin and trimethoprim-sulfamethoxazole. All the isolates were susceptible to vancomycin and linezolid. All the MDR-MRSA harbored SCCmec type III. All the MDR- MRSA isolates were strong biofilm producers in the phenotypic test. Conclusions: Multidrug-resistant MRSA isolates produced biofilm strongly and the majority of these isolates harbored most of biofilm related genes.Bangladesh Journal of Infectious Diseases 2014;1(2):27-31


2007 ◽  
Vol 28 (1) ◽  
pp. 95-97 ◽  
Author(s):  
Garrett E. Schramm ◽  
Jennifer A. Johnson ◽  
Joshua A. Doherty ◽  
Scott T. Micek ◽  
Marin H. Kollef

The incidence of community-associated, healthcare-associated, and hospital-acquired sterile-site infections due to methicillin-re-sistant Staphylococcus aureus (MRSA) isolates and the susceptibility of the isolates to non-β-lactam antibiotics were evaluated for 549 hospitalized patients during a 3-year period. The incidence of community-associated MRSA infection increased significantly. The annual percentage of MRSA isolates from cases of healthcare-associated and hospital-acquired infection that were susceptible to 3 or more non-β-lactam antibiotics increased significantly.


Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 427
Author(s):  
Martyna Kasela ◽  
Agnieszka Grzegorczyk ◽  
Bożena Nowakowicz-Dębek ◽  
Anna Malm

Nursing homes (NH) contribute to the regional spread of methicillin-resistant Staphylococcus aureus (MRSA). Moreover, residents are vulnerable to the colonization and subsequent infection of MRSA etiology. We aimed at investigating the molecular and phenotypic characteristics of 21 MRSA collected from the residents and personnel in an NH (Lublin, Poland) during 2018. All MRSA were screened for 20 genes encoding virulence determinants (sea-see, eta, etb, tst, lukS-F-PV, eno, cna, ebpS, fib, bbp, fnbA, fnbB, icaADBC) and for resistance to 18 antimicrobials. To establish the relatedness and clonal complexes of MRSA in NH we applied multiple-locus variable-number tandem-repeat fingerprinting (MLVF), pulse field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. We identified four sequence types (ST) among two clonal complexes (CC): ST (CC22) known as EMRSA-15 as well as three novel STs—ST6295 (CC8), ST6293 (CC8) and ST6294. All tested MRSA were negative for sec, eta, etb, lukS-F-PV, bbp and ebpS genes. The most prevalent gene encoding toxin was sed (52.4%; n = 11/21), and adhesins were eno and fnbA (100%). Only 9.5% (n = 2/21) of MRSA were classified as multidrug-resistant. The emergence of novel MRSA with a unique virulence and the presence of epidemic clone EMRSA-15 creates challenges for controlling the spread of MRSA in NH.


2021 ◽  
Vol 12 (1) ◽  
pp. 16-20
Author(s):  
Samiah Hamad S Al-Mijalli

Diabetic foot infections (DFIs) are a significant health issue and a common complication among patients with diabetes. To develop antibiotic therapy for these high-risk patients, the current study evaluates the scope of DFIs and identifies the causing microbes. It also measures spectrum and antibiotic susceptibility of the pathogens isolated from adults with DFIs in Saudi Arabia. To achieve the study objectives, a cross-sectional study was implemented and the baseline characteristics for 44 patients with DFIs were defined. Optimal aerobic and anaerobic microbiological techniques were utilized to culture specimens isolated from infected foot ulcers. The standard microbiological methods were employed to identify the bacterial isolates and antibiotic susceptibility testing was conducted following the procedures of the Clinical and Laboratory Standards Institute (CLSI). Results showed that 12 microorganisms were isolated from the participants’ diabetic foot ulcers. Staphylococcus Aureus was ranked first because it appeared in 29 (65.9%) cases. Streptococcus Agalactiae was ranked second and multi-microbial infections were also found. Most of the organisms were susceptible to Vancomycin, Ciprofloxacin, and Cefalexin, but they were resistant to Methicillin, Gentamicin, and Ampicillin antibiotics. Staphylococcus Aureus was most sensitive to Ciprofloxacin, while it was resistant to Methicillin. About 10% of the isolates were multidrug-resistant. The study concludes that while Vancomycin should be used empirically for Gram-positive isolates, Ciprofloxacin can be taken into consideration for most of the Gram-negatives aerobes. Based on including various microorganisms and the advent of multidrug-resistant strains, proper culture and sensitivity testing are necessary prior to the empirical therapy.


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