scholarly journals Comparative activity of linezolid and other new agents against methicillin-resistant Staphylococcus aureus and teicoplanin-intermediate coagulase-negative staphylococci

2001 ◽  
Vol 48 (6) ◽  
pp. 911-913 ◽  
Author(s):  
C. Betriu
2020 ◽  
Author(s):  
Ujjwal Ranjan Dahiya ◽  
Arnab Sikidar ◽  
Priyanka Sharma ◽  
Chitra Rawat ◽  
Benu Dhawan ◽  
...  

Methicillin-resistant staphylococcus aureus (MRSA) is an extremely infectious hospital acquired bacterial pathogen often found in post-surgical patients globally. Early detection of such pathogens is a critical requirement to eliminate or reduce the incidence of antimicrobial resistance as well as for effective management of the disease. Despite the development of multiple biochemical, microbiological and nucleic acid amplification techniques (NAATs), conventional culture methods are widely used clinically owing to high variability between the methods, technical skills, and infrastructural needs. Further, multiple reports suggest a significant variation among diagnostic output for MRSA detection. This work attempts to probe the discordance among the diagnostic output of three commonly used methods while trying to understand the underlying cause of variability. MRSA detection on 217 clinical pus isolates was carried out using three different methods namely, conventional culture method, qPCR-based amplification, and a modern LAMP-based detection approach. Also, to confirm the presence of MRSA and distinguish from coagulase-negative staphylococci (CoNS), as well as to investigate the observed differences between qPCR and LAMP outputs, melt curve analysis was performed on discordant samples. LAMP-based MRSA detection was found to be the optimum method. In summary, this study evaluates the diagnostic efficiency of the different detection methods, while probing for possible explanations for the observed differences.


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.


2000 ◽  
Vol 44 (3) ◽  
pp. 489-495 ◽  
Author(s):  
Rie Nagano ◽  
Kaneyoshi Shibata ◽  
Yuka Adachi ◽  
Hideaki Imamura ◽  
Terutaka Hashizume ◽  
...  

ABSTRACT The in vitro activities of the novel 1β-methylcarbapenems J-111,225, J-114,870, and J-114,871, which have a structurally unique side chain that consists of a trans-3,5-disubstituted 5-arylpyrrolidin-3-ylthio moiety at the C-2 position, were compared with those of reference antibiotics. Among isolates of both methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci (MRCoNS), 90% were inhibited by J-111,347 (prototype), J-111,225, J-114,870, and J-114,871 at concentrations of 2, 4, 4, and 4 μg/ml (MICs at which 90% of isolates are inhibited [MIC90s]), respectively, indicating that these agents were 32- to 64-fold more potent than imipenem, which has an MIC90 of 128 μg/ml. Although these drugs were less active in vitro than vancomycin, which had MIC90s of 1 and 2 μg/ml for MRSA and MRCoNS, respectively, the new carbapenems displayed better killing kinetics than vancomycin. The potent anti-MRSA activity was ascribed to the excellent affinities of the new carbapenems for penicillin-binding protein 2a of MRSA. Since the new carbapenems also exhibited good activity against gram-positive and -negative bacteria including clinically important pathogens such as penicillin-resistantStreptococcus pneumoniae, Haemophilus influenzae, members of the family Enterobacteriaceae,Pseudomonas aeruginosa, and Clostridium difficile, as well as MRSA, the novel carbapenems are worthy of further evaluation.


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