scholarly journals Multiplex Polymerase Chain Reaction Based Typing of Staphylococcal Chromosomal Cassette mec of Methicillin Resistant Staphylococcus aureus from Selected Hospitals in Lahore

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Romeeza T ◽  
Naeem R ◽  
Nadeem A

Introduction: Staphylococcus aureus is one of the leading causes of nosocomial infections. Prevalence of methicillin resistant Staphylococcus aureus (MRSA) has been reported in up to 42% of isolates in Pakistan. Methicillin resistance is encoded by the mecA gene and it is transferred by a unique genetic vector called staphylococcal chromosomal cassette (SCCmec). Depending upon the selection pressures of antibiotics, different types of SCCmec elements may prevail in different parts of the world. Materials and Methods: Therefore, this study was designed to fi nd out the major SCCmec types present in selected hospitals of Lahore. For this purpose thirty fi ve MRSA isolates were collected. These strains were reconfi rmed and SCCmec types were determined by multiplex PCR. Results: It was found that 21 (60%) isolates possess SCCmec type IA while 14 (40%) isolates possess SCCmec type IIC. Conclusion: These cassettes are shown to be multiresistant and have not been reported in other Asian countries so far.

2019 ◽  
Vol 12 (11) ◽  
pp. 1760-1768 ◽  
Author(s):  
Nimita Venugopal ◽  
Susweta Mitra ◽  
Rituparna Tewari ◽  
Feroze Ganaie ◽  
Rajeswari Shome ◽  
...  

Background and Aim: Methicillin-resistant staphylococci are among the emerging pathogens which have become a threat to both human and animal health. The present investigation intended to examine the occurrence and the molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci (MRCoNS) recovered from cattle, its handlers, and their environment. Materials and Methods: A total of 666 specimens were subjected to culture method and genus-specific polymerase chain reaction (PCR) for the identification of Staphylococcus. Methicillin resistance was substantiated by PCR identification of mecA and mecC resistance determinants. Species-specific identification of mecA positive isolates was conducted by multiplex PCR. The unidentified species were deciphered by 16S rRNA gene sequencing approach. The mecA positive isolates were further characterized by staphylococcal cassette chromosome mec (SCCmec) typing and multilocus sequence typing (MLST). Results: Duplex PCR identified 728 Staphylococcus isolates, of which 66 (9%) were positive for mecA gene. MRSA constituted 24% of the total mecA positive isolates. Among MRCoNS, Staphylococcus epidermidis (42%), and Staphylococcus haemolyticus (11%) were the most common species identified. Overall, 47% of the mecA positive isolates belonged to SCCmec type V. MLST analysis showed eight different sequence types (STs) among MRSA isolates of which five were novel STs. Among methicillin-resistant S. epidermidis, 19 different STs were found, of which nine novel STs were detected. Conclusion: The increase in the prevalence of mecA positive staphylococci, especially MRCoNS in cattle is a great concern in view of their transmission potential. Hence, continuous monitoring and molecular characterization of methicillin-resistant staphylococci should be elucidated in human and animal sectors so as to prevent the spread of these resistant pathogens.


Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 256
Author(s):  
Cyrille Ngassam Tchamba ◽  
Jean-Noël Duprez ◽  
Pierrick Lucas ◽  
Yannick Blanchard ◽  
Filip Boyen ◽  
...  

Methicillin-resistant Staphylococcus aureus (MRSA) and non-aureus staphylococci (MRNAS) cause different infections in animals, including mastitis, in livestock and humans. This study aimed to identify and compare the staphylococcal chromosome cassette mec (SCCmec) types of MRSA or MRNAS isolated from several animal species and humans in different countries. Of 1462 S. aureus and non-aureus staphylococci, 68 grew on Chrom MRSA ID® agar, were phenotypically resistant to cefoxitin and tested positive with the PCR for the mecA gene. These 60 MRSA and 8 MRNAS were isolated in Belgium mainly from cows (livestock-associated (LA) MRS) and humans (community-acquired (CA) MRS) and in Japan from dogs and cats. The SCCmec cassettes were identified by multiplex PCR in 52 MRSA and 7 MRNAS and by whole genome sequencing (WGS) in 8 additional MRSA. The SCCmec types IV and V were the most frequent in Belgian LA-MRS and CA-MRS, while the SCCmec type II was identified in four of the five Japanese MRSA. The remaining isolate was a bovine S. haemolyticus in which no SCCmec was identified. These results confirm the high prevalence of the SCCmec types IV and V in LA-MRS and CA-MRS in Belgium, emphasizing the possible public health hazard of the former, and the absence of SCCmec in some MRNAS.


Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 430
Author(s):  
Wichai Santimaleeworagun ◽  
Praewdow Preechachuawong ◽  
Wandee Samret ◽  
Tossawan Jitwasinkul

Methicillin-resistant Staphylococcus aureus (MRSA) is mostly found in Thailand in the hospital as a nosocomial pathogen. This study aimed to report the genetic characterization of a clinical community-acquired MRSA (CA-MRSA) isolate collected from hospitalized patients in Thailand. Among 26 MRSA isolates, S. aureus no. S17 preliminarily displayed the presence of a staphylococcal cassette chromosome mec (SCCmec) type IV pattern. The bacterial genomic DNA was subjected to whole-genome sequencing. Panton–Valentine leukocidin (PVL) production, virulence toxins, and antibiotic resistance genes were identified, and multi-locus sequence typing (MLST) and spa typing were performed. The strain was matched by sequence to MLST type 2885 and spa type t13880. This strain carried type IV SCCmec with no PVL production. Five acquired antimicrobial resistance genes, namely blaZ, mecA, Inu(A), tet(K), and dfrG conferring resistance to β-lactams, lincosamides, tetracycline, and trimethoprim, were identified. The detected toxins were exfoliative toxin A, gamma-hemolysin, leukocidin D, and leukocidin E. Moreover, there were differences in seven regions in CR-MRSA no. S17 compared to CA-MRSA type 300. In summary, we have reported the ST2885-SCCmec IV CA-MRSA clinical strain in Thailand for the first time, highlighting the problem of methicillin resistance in community settings and the consideration in choosing appropriate antibiotic therapy.


2020 ◽  
Vol 27 (07) ◽  
pp. 1363-1370
Author(s):  
Aneela Khawaja ◽  
Iffat Javed ◽  
Sohaila Mushtaq ◽  
Saeed Anwar ◽  
Faiqa Arshad ◽  
...  

Antimicrobial resistance (AMR) is a devastating question that is threatening the health globally. The extensive and indiscriminative use of antibiotics has evolved a notorious resistance in Staphylococcus aureus.  This resistance developed through possession of mecA gene, which codes for modified penicillin binding protein (PBP2a) and the emergent strain being labeled “methicillin resistant Staphylococcus aureus”. Conventional phenotypic techniques for detection of MRSA rely on standardization of cultural characteristics. The drawbacks of diagnostic error to report MRSA include: poor prognosis, expensive treatment, dissemination of multi-drug resistant strains and even treatment failure. Latex agglutination method can be adopted as a more accurate and quick strategy for rapid detection of methicillin resistance. Objectives: To compare detection of mecA gene in methicillin resistant isolates of Staphylococcus aureus by latex agglutination and PCR; by assessing the sensitivity and specificity of both methods. Study Design: Descriptive Cross-Sectional study. Setting: Pathology Department, Post Graduate Medical Institute, Lahore. Period: From January 2015 to December 2015; according to standard operating procedures at Microbiology laboratory. Material & Methods: A total 713 consecutive, non-duplicate isolates of Staphylococcus aureus were processed. Methicillin resistance was determined using cefoxitin (30mg) by Kirby-Bauer method using CLSI guideline (2016), latex agglutination method; and PCR for mecA gene. Results: The results showed that out of 713 Staphylococcus aureus isolates, 92 (12.90%) isolates were resistant to cefoxitin and were labelled as MRSA. majority MRSA isolates recovered from pus (44.57%) and wound swab (20.65%), followed by blood (13.04%), fluid (8.70%), CSF (4.35%), CVP (3.26%), HVS (3.26%) and tracheal secretion (2.17%). By latex agglutination method, 87 (94.50%) were positive for PBP2a; while on PCR mecA gene was detected only in 82 (89.10%) MRSA isolates. When assessed with PCR (gold standard) the sensitivity and diagnostic accuracy of latex agglutination was 100% and 94.57%, respectively. Conclusion: Latex agglutination test can be employed as rapid and reliable diagnostic technique in MRSA isolates for mecA gene detection, where resources for molecular methods are inadequate. This can effectually lessen the misdiagnosis of resistant strains, and over/ ill-use of antibiotics.


2019 ◽  
Vol 7 (4) ◽  
pp. 121-125
Author(s):  
Fatemeh Mahdavi ◽  
Fatemeh Zaboli ◽  
Rahem Khoshbakht

Background: Methicillin-resistant Staphylococcus aureus (MRSA) strains are one of the most important multidrug resistant microorganisms that threaten human health. Objective: The present study was conducted to evaluate genotypic and phenotypic characteristics of erythromycin resistance among MRSA isolates recovered from raw milk in Iran. Materials and Methods: A total of 50 MRSA isolates were recovered from raw milk. Tests for erythromycin and clindamycin susceptibility and inducible clindamycin resistance were done. In addition, the presence of the methicillin resistance determinant (mecA), erythromycin resistance genes (ermA, ermB, ermC and msrA) and an important virulence gene (Panton– Valentine leukocidin) were investigated using polymerase chain reaction (PCR) method. Results: Forty-eight percent (24/50) and 46% (23/50) of the isolates were resistant to erythromycin and clindamycin, respectively. Seven (14%) isolates showed inducible clindamycin resistance phenotype. The mecA gene was detected in 88% (44/50) of MRSA isolates. The incidence of the ermA, ermB, ermC and msrA genes was 14%, 64%, 12%, and 26%, respectively and the PVL gene was present in 18% (9/50) of MRSA isolates. Conclusion: According to the results of the study, the incidence of erythromycin resistance genes and inducible clindamycin-resistant MRSA strains was high in raw milk samples in Iran.


2020 ◽  
Vol 6 (10) ◽  
pp. FSO619
Author(s):  
Ibrahim A Musawa ◽  
Yusuf Yakubu ◽  
Bashiru Garba ◽  
Fatimah M Ballah ◽  
Hassan Abdurrahman Jibril ◽  
...  

Aim: To evaluate the role of dressed chicken in the spread of methicillin-resistant Staphylococcus aureus (MRSA) in Sokoto, Nigeria. Materials and methods: 190 chicken carcass rinsates were subjected to culture and biochemical analyses to isolate and identify MRSA. PCR was used to amplify mecA gene that is responsible for methicillin resistance. Results & conclusion: Culture and molecular analysis showed 19.5% (37/190) of the rinse had MRSA on oxacillin-resistance screening agar base (ORSAB) with 7.9% (15/190) possessing the mecA gene. Significant association (p = 0.044) exist between local-chicken and presence of MRSA, being twice more likely to have MRSA compared to exotic-chickens (odds ratio [OR] = 2.132). Results indicate possible role of dressed-chicken in the spread of MRSA. Authorities should regulate the sale and use of antibiotics by farmers, and enhance hygienic practices at slaughterhouses.


Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 214 ◽  
Author(s):  
Kim ◽  
Kim ◽  
Chung ◽  
Chung ◽  
Han ◽  
...  

Methicillin-resistant Staphylococcus aureus (MRSA) is a serious pathogen in clinical settings and early detection is critical. Here, we investigated the MRSA discrimination potential of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) using 320 clinical S. aureus isolates obtained in 2005–2014 and 181 isolates obtained in 2018. We conducted polymerase chain reactions (PCR) for staphylococcal cassette chromosome mec (SCCmec) typing and MALDI-TOF MS to find specific markers for methicillin resistance. We identified 21 peaks with significant differences between MRSA and methicillin-susceptible S. aureus (MSSA), as determined by mecA and SCCmec types. Each specific peak was sufficient to discriminate MRSA. We developed two methods for simple discrimination according to these peaks. First, a decision tree for MRSA based on six MRSA-specific peaks, three MSSA-specific peaks, and two SCCmec type IV peaks showed a sensitivity of 96.5%. Second, simple discrimination based on four MRSA-specific peaks and one MSSA peak had a maximum sensitivity of 88.3%. The decision tree applied to 181 S. aureus isolates from 2018 had a sensitivity of 87.6%. In conclusion, we used specific peaks to develop sensitive MRSA identification methods. This rapid and easy MALDI-TOF MS approach can improve patient management.


Author(s):  
Seighazi Regina Egege ◽  
Nedie Patience Akani ◽  
Chidiebele Emmanuel Ikechukwu Nwankwo

Aims/Objective: Methicillin-Resistant Staphylococcus aureus (MRSA) is a dominant cause of severe healthcare-associated (HA) infections but has recently emerged as Community-Associated (CA-MRSA) and Livestock-Associated MRSA (LA-MRSA). This study was carried out to detect the presence of Methicillin-Resistant S. aureus in Ready-to-Eat (RTE) Corbiculid heterodont in Bayelsa state, Nigeria. Place of Study: This study was conducted in Yenagoa, Southern Ijaw and Sagbama Local Government Areas, Bayelsa State, Nigeria. Methodology: Fifty-three samples (dried, fried and stewed) of the RTE C. heterodont were collected and subjected to standard microbiological procedures. Results: Seventy Staphylococcus spp. were isolated, consisting of 65 (92.86%) S. aureus and 5 (7.14%) coagulase negative Staphylococcus (CONS). Out of the 65 S. aureus isolates, 53.8% were MRSA. Susceptibility pattern of MRSA showed a decreasing trend of resistance in the order: Amoxacillin, Ampicillin-Cloxacillin, Cefoxitin, and Oxacillin (100%) > Streptomycin (82.9%) >Ceftriaxone (40%) >Cefuroxime (31.4%), > Ciprofloxacin and Trimethoprim-Sulfamethoxazole (17.1%) > Gentamycin and Pefloxacin (8.6%) > Erythromycin (2.9%).Out of the 65 S. aureus isolates, 62 (95.4%) had Multidrug Resistance Index > 0.2 while 3 (4.6%) had 0.2 as their Multidrug Resistance Index. The MRSA isolates were 100% Multidrug Resistant (MDR) while the Methicillin-Sensitive S. aureus (MSSA) were 90% MDR. Molecular characterization of ten S. aureus isolates confirmed 80% S. aureus isolates and 20% CONS (S. sciuri and S. warneri).  Polymerase chain reaction (PCR) and Agarose gel-electrophoresis were used to detect the presence of mecA gene, a gene that confers methicillin resistance. The mecA gene with size 500bp was identified in 50% of MRSA. This study reported presence of MRSA and MDR S. aureus in C. heterodont sold in Bayelsa state, Nigeria. This could be the avenue for the spread of MRSA. Public health awareness campaigns should be advocated to enhance hygienic practices in the handling and distribution of food.


QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
R A Mohamed ◽  
L F Fathi ◽  
N N Salaheldeen

Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen that is associated with both hospital and community infections. Panton Valentine leukocidin (PVL) is an important virulence factor of S. aureus that is considered by many authors a marker of community acquired MRSA (CA-MRSA). Aim of the Work This study aimed to determine the prevalence of PVL genes among healthcare acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) and CA-MRSA isolates, and to test the hypothesis that PVL is a reliable marker of CA-MRSA isolates. Material and Methods This comparative cross-sectional study was done on fifteen community acquired methicillin resistant Staphylococcus aureus (CA-MRSA) and fifteen hospital acquired methicillin resistant Staphylococcus aureus (HA-MRSA), obtained from patients attending outpatient clinics, presenting with community-acquired pyogenic infections and patients with healthcare acquired pyogenic infections in Intensive Care Units (ICUs), during the period from May 2017 till February 2018. Clinical specimens included pus and different body fluids. Staphylococcus aureus was isolated and identified using conventional microbiological methods3. Isolates were then tested for methicillin resistance by culture on mannitol salt agar (MSA) with cefoxitin4. The presence of mecA and pvl genes in all MRSA isolates was subsequently detected by PCR5,6. Results Among 15 HA-MRSA isolates, mecA gene was positive in 40% (6/15) of isolates, while pvl gene was positive in 53.3% (8/15) of isolates. Among 15 CA-MRSA isolates, mecA gene was positive in 46.7% (7/15) of isolates, while pvl gene was positive in 26.7% (4/15) of isolates. Conclusion We conclude that pvl gene is not a sole genetic marker for diagnosis CA-MRSA, as there was no significant correlation between mecA that encodes for methicillin resistance and pvl genes among fifteen CA-MRSA isolates (P value =1).


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