scholarly journals β-lactam resistance in coagulase-negative Staphylococcus isolated from subclinical goat mastites

2021 ◽  
Vol 56 ◽  
Author(s):  
Amanda Pereira Lucas ◽  
Elizabete Cristina da Silva ◽  
Andriele Renata Barbosa de Farias ◽  
Maria Priscilla Borges de Albuquerque ◽  
Luciana Florêncio Vilaça Lopes ◽  
...  
Keyword(s):  
Meca Gene ◽  
Resistance Mechanisms ◽  
Disk Diffusion ◽  
Penicillin Resistance ◽  
Coagulase Negative Staphylococcus ◽  
Poor Agreement ◽  
Chain Reaction ◽  
Resistance To Penicillin ◽  
Polymerase Chain ◽  
Phenotypic Methods

Abstract: The objective of this work was to evaluate resistance mechanisms to β-lactam antimicrobials in 251 strains of coagulase-negative Staphylococcus (CoNS) isolated from subclinical goat mastitis, as well as to determine the sensitivity and specificity of the nitrocefin and disk diffusion methods to detect penicillin resistance, in comparison with the polymerase chain reaction (PCR). The isolates were evaluated for the presence of the blaZ and mecA genes, β-lactamase production, and susceptibility to penicillin. Of the total isolates, 228 (91%) carried the blaZ gene and, among these, 144 (63%) were positive for β-lactamase production. Resistance to penicillin was observed in 125 of the isolates, of which 96.8% carried the blaZ gene. The sensitivity of the phenotypic methods to detect β-lactamase production was low, but their specificity was high; the Kappa coefficient showed a poor agreement between the phenotypic methods and PCR. The mecA gene was detected in only 3% of the isolates, which were identified as belonging to the species: S. capitis subsp. ureolyticus, S. caprae, S. warneri, S. sciuri, S. simulans, and S. cohnii subsp. urealyticum. Coagulase-negative Staphylococcus are important mastitis-causing pathogens in goat and harbor the blaZ and mecA genes related to resistance to β-lactam antimicrobials. The sensitivity of the nitrocefin and disk diffusion methods to detect penicillin resistance is low in relation to that of PCR.

scholarly journals Detection of Methicillin Resistance in Staphylococcus Aureus by Polymerase Chain Reaction and Conventional Methods: A Comparative Study

2012 ◽  
Vol 4 (02) ◽  
pp. 083-088 ◽  
Author(s):  
Manju M Pillai ◽  
Ragunathan Latha ◽  
Gautam Sarkar
Keyword(s):  
Staphylococcus Aureus ◽  
Polymerase Chain Reaction ◽  
Methicillin Resistance ◽  
Meca Gene ◽  
Disk Diffusion ◽  
Chain Reaction ◽  
Mannitol Salt Agar ◽  
Polymerase Chain ◽  
Conventional Methods ◽  
Phenotypic Methods

ABSTRACT Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen worldwide, which has emerged over the past 30 years as a leading cause of both nosocomial and community-acquired infections. Accurate and rapid identification of MRSA in clinical specimens is essential for timely decision on effective antimicrobial chemotherapy. Aim: The present study was conducted to compare two conventional phenotypic methods, oxacillin disk diffusion (ODD) Aim: The present study was conducted to compare two conventional phenotypic methods, oxacillin disk diffusion (ODD) method and mannitol salt agar (MSA) with oxacillin, with polymerase chain reaction (PCR) for mecA gene (as standard). Materials and Methods: A total of 165 consecutive clinical isolates of S. aureus received at the Department of Microbiology in our tertiary care teaching hospital were included in the study. All the isolates were subjected to ODD (1 μg) method, culture in MSA with oxacillin, and PCR for mecA gene. Results: The sensitivity and specificity of ODD test were found to be 93.5% (86.4-97.3%) and 83.5% (79.2-85.8%), respectively, and that of MSA with oxacillin were found to be 87.1% (79.5-92.3%) and 89.3% (84.8-92.5%), respectively. The time taken for diagnosing MRSA by conventional methods is 48-72 h, which is more as compared to PCR which takes 18-24 h. Conclusion: This study recommends advocating PCR for mecA gene on a regular basis for detecting methicillin resistance in S. aureus isolates isolated from sterile body fluids or from special units such as intensive care units.

scholarly journals IDENTIFICATION OF AMPC Β-LACTAMASE-PRODUCING CLINICAL ISOLATES OF ESCHERICHIA COLI

2017 ◽  
Vol 10 (12) ◽  
pp. 357
Author(s):  
Tanushree Barua Gupta ◽  
Malini Shariff ◽  
Thukral Ss ◽  
S.s Thukral
Keyword(s):  
Escherichia Coli ◽  
Detection Method ◽  
Clinical Isolates ◽  
Confirmatory Test ◽  
Chain Reaction ◽  
E Coli ◽  
Resistance To Penicillin ◽  
Polymerase Chain ◽  
Third Generation Cephalosporins

  Objective: Indiscriminate use of β-lactam antibiotics has resulted in the emergence of β-lactamase enzymes. AmpC β-lactamases, in particular, confer resistance to penicillin, first-, second-, and third-generation cephalosporins as well as monobactams and are responsible for antibiotic resistance in nosocomial pathogens. Therefore, this study was undertaken to screen nosocomial Escherichia coli isolates for the presence and characterization of AmpC β-lactamases. The study also envisaged on the detection of inducible AmpC β-lactamases and extended-spectrum β-lactamases (ESBLs) in AmpC β-lactamase-producing E. coli.Methods: A total of 102 clinical isolates of E. coli, were subjected to cefoxitin screening, and screen-positive isolates were further subjected to inhibitor-based detection method, phenotypic confirmatory test, disc antagonism test, polymerase chain reaction (PCR), and isoelectric focusing (IEF).Results: In this study, 33% of E. coli were resistant to cefoxitin, of which 35% were found to be positive for AmpC β-lactamase by inhibitor-based phenotypic test. Of the AmpC-positive isolates, 83% were positive for ESBLs, whereas 25% were producing inducible AmpC β-lactamases. PCR and IEF showed CIT and EBC types of AmpC β-lactamases present in the tested isolates.Conclusion: Our study showed the presence of inducible AmpC enzymes and ESBLs in E. coli isolates and PCR identified more isolates to be AmpC producers.

scholarly journals Antimicrobial Resistance of Staphylococcus sp. Isolated from Cheeses

Animals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 36
Author(s):  
Jana Výrostková ◽  
Ivana Regecová ◽  
František Zigo ◽  
Boris Semjon ◽  
Gabriela Gregová
Keyword(s):  
Polymerase Chain Reaction ◽  
Antimicrobial Resistance ◽  
Meca Gene ◽  
Common Species ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Chain Reaction ◽  
Coagulase Negative Staphylococci ◽  
Flight Mass Spectrometry ◽  
Polymerase Chain

S. aureus and some species of coagulase-negative staphylococci, including S. chromogenes and S. simulans, commonly cause intramammary infections. However, little attention was paid to the antimicrobial resistance of these species with respect to their occurrence in dairy products, for example, popular sheep and goat cheeses made from unpasteurized milk. The aim of this study was to investigate such sheep and goat cheeses for the occurrence and antimicrobial resistance of the relevant staphylococci species. The staphylococcal isolates were identified by polymerase chain reaction (130 isolates) and matrix assisted laser desorption/ionization time-of-flight mass spectrometry. The most common species of S. aureus (56 isolates) were identified, as well as S. chromogenes (16 isolates) and S. simulans (10 isolates). Antimicrobial resistance to penicillin, oxacilin, ceftaroline, teicoplanin, gentamicin, erythromycin, tetracycline and ofloxacin was subsequently determined in these species using the agar dilution method. The highest resistance was confirmed in all species, especially to penicillin (91%) and erythromycin (67%). The highest sensitivity was confirmed to ofloxacin (83%). Due to the high incidence of penicillin and oxacilin-resistant staphylococci, the mecA gene was detected by polymerase chain reaction, which was confirmed only in S. aureus isolates (19%). Our study shows that the tested strains (77%) were resistant to more than one antibiotic at a time.

Ceftazidime – Avibactam susceptibility among carbapenem-resistant Enterobacterales in a pilot study in Turkey

2021 ◽  
Author(s):  
Hasan Selcuk Ozger ◽  
Ebru Evren ◽  
Serap Suzuk Yildiz ◽  
Cigdem Erol ◽  
Fatma Bayrakdar ◽  
...  
Keyword(s):  
Practical Method ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Drug Resistant ◽  
Chain Reaction ◽  
Disk Diffusion Method ◽  
Carbapenem Resistant ◽  
Therapeutic Choice ◽  
Polymerase Chain

AbstractThis study aimed to detect carbapenemase genes and to determine the in vitro susceptibility of Ceftazidime-Avibactam (CZA) in Enterobacterales isolates. Carbapenemase genes were detected by polymerase chain reaction. CZA sensitivity of isolates was evaluated with broth microdilution (BMD) and disk diffusion methods. A total of 318 carbapenem-resistant Enterobacterales isolates were included. Most of the isolates (n = 290, 91.2%) were identified as Klebsiella pneumoniae. The most common carbapenemase type was OXA-48 (n = 82, 27.6%). CZA susceptibility was evaluated in 84 isolates with OXA-48 and KPC carbapenemase activity. Both BMD and disk diffusion methods revealed that 95.2% of the isolates were sensitive to CZA; whereas, 4 (4.76%) isolates were resistant to CZA. Among colistin resistant isolates, 96.5% (n = 80) of them were susceptible to CZA. Our study demonstrated high in vitro efficacy of CZA in Enterobacterales isolates producing OXA-48 carbapenemase. High susceptibility rates against colistin resistant isolates which generally are also pan drug resistant, makes CZA a promising therapeutic choice for difficult-to-treat infections. Due to its high correlation with the BMD, disk diffusion method is a suitable and more practical method in detecting CZA in vitro activity.

scholarly journals Detection of mecA Gene of Methicillin Resistant Staphylococci from Oral Swabs by Polymerase Chain Reaction

1993 ◽  
Vol 67 (1) ◽  
pp. 12-17 ◽  
Author(s):  
Yasuhito HIGASHIYAMA ◽  
Hironobu KOGA ◽  
Shigeru KOHNO ◽  
Shigefumi MAESAKI ◽  
Mitsuo KAKU ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Meca Gene ◽  
Chain Reaction ◽  
Methicillin Resistant ◽  
Polymerase Chain
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