scholarly journals Growing Resistance to Vancomycin among Methicillin Resistant Staphylococcus Aureus Isolates from Different Clinical Samples

2014 ◽  
Vol 52 (196) ◽  
pp. 977-981 ◽  
Author(s):  
Prakash Chandra Pahadi ◽  
Upendra Thapa Shrestha ◽  
Nabaraj Adhikari ◽  
Pradeep Kumar Shah ◽  
Ritu Amatya
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Control Measures ◽  
Clinical Samples ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Methicillin Resistant

Introduction: Methicillin resistant Staphylococcus aureus (MRSA), majorly associated with nosocomial and community infections worldwide, are emerging as resistant strains to many antibiotics narrowing down the efficacy of antimicrobial therapy. In order to investigate the changing resistant pattern of MRSA to empirical drugs, the study was carried out at KIST Medical College and Hospital, Nepal. It also aims to determine the minimum inhibitory concentration of vancomycin among MRSA. Methods: Altogether 3500 clinical samples including 1303 blood, 1489 urine and 708 body fluids were collected and processed. Isolated S. aureus were further screened for methicillin resistance by Kirby-Bauer disk diffusion technique using cefoxitin (30μg) disk. All MRSA were subjected to in vitro determination of MIC of vancomycin by agar dilution method as recommended by CLSI guidelines. Results: Total 287 S. aureus were isolated from the different clinical samples. Altogether 248 (86.41%) were found to be multidrug resistance (MDR) while 42 (14.63%) of the isolates were methicillin resistance with the highest prevalence in the age group of 16-30. All 42 (100%) MRSA isolates were resistant to ampicillin and penicillin followed by 41 (97.62%), 32 (76.19%), 31(73.81%), 29 (69.05%), 9 (21.43%) and seven (16.67%) to cefotaxime, gentamycin, cotrimoxazole, erythromycin, tetracycline and ciprofloxacin respectively. Although all MRSA strains were sensitive to vancomycin on disc diffusion, four isolates were intermediates in vitro determination of MIC of vancomycin. The break point for vancomycin was found to be 15mm. Conclusions: The increment in vancomycin MIC among MRSA is alarming. Strict control measures to prevent MRSA spread and a routine surveillance for VRSA must be incorporated in hospitals.  Keywords: mdr; mrsa; mic; visa; vrsa.

scholarly journals In Vitro Activities of Ceftobiprole, Tigecycline, Daptomycin, and 19 Other Antimicrobials against Methicillin-Resistant Staphylococcus aureus Strains from a National Survey of Belgian Hospitals

2006 ◽  
Vol 50 (8) ◽  
pp. 2680-2685 ◽  
Author(s):  
Olivier Denis ◽  
Ariane Deplano ◽  
Claire Nonhoff ◽  
Marie Hallin ◽  
Raf De Ryck ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Therapeutic Potential ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Methicillin Resistant ◽  
Excellent Activity ◽  
Agar Dilution

ABSTRACT The in vitro activities of 22 antimicrobial agents, including ceftobiprole, daptomycin, and tigecycline, against 511 methicillin-resistant Staphylococcus aureus (MRSA) isolates from 112 Belgian hospitals were studied by using the CLSI agar dilution method. Isolates were characterized by pulsed-field gel electrophoresis (PFGE) analysis and by PCR detection of determinants of resistance to aminoglycosides, macrolides-lincosamides-streptogramins, and tetracyclines. A representative set of isolates with different PFGE genotypes was further characterized by multilocus sequence typing, determination of staphylococcal cassette chromosome mec (SCCmec) type, and multiplex PCR for toxic shock syndrome type 1 (TSST-1) and Panton-Valentine leukocidin genes. MRSA isolates belonged to nine epidemic MRSA clones, of which sequence type 45 (ST45)-SCCmec IV and ST8-SCCmec IV were predominant, accounting for 49 and 20% of isolates, respectively. The distribution of antimicrobial resistance and TSST-1 genes was strongly linked to clonal types. Ceftobiprole, daptomycin, and tigecycline showed high activity against all isolates of these sporadic and epidemic MRSA clones, as indicated by MIC90s of 2 mg/liter, 0.5 mg/liter, and 0.25 mg/liter, respectively. The MIC distribution of daptomycin and tigecycline was not different in isolates with decreased susceptibility to glycopeptides or tetracyclines, respectively. Ceftobiprole MICs were not correlated with oxacillin and cefoxitin MICs. These data indicate excellent activity of the newly developed agents ceftobiprole, daptomycin, and tigecycline against MRSA isolates recently recovered from hospitalized patients in Belgium, supporting their therapeutic potential for nosocomial MRSA infections.

scholarly journals COMPARATIVE IN- VITRO EVALUATION OF VANCOMYCIN MINIMUM INHIBITORY CONCENTRATIONBY AGAR DILUTION AND E-STRIP IN METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS

2021 ◽  
Vol 71 (1) ◽  
pp. 150-54
Author(s):  
Sheroze Ilyas ◽  
Tehmina Munir ◽  
Rabia Sadaf ◽  
Mehreen Gilani
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Military Hospital ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Methicillin Resistant ◽  
Medical College ◽  
National University ◽  
Agar Dilution

Objective: To compare the in-vitro efficacy by determining Minimum Inhibitory Concentration of Vancomycinusing the reference Agar Dilution to the E-Strip in Methicillin Resistant Staphylococcus aureus isolates. Study Design: Validation study. Place and Duration of Study: The department of Microbiology Army Medical College/National University ofMedical Sciences in collaboration with Pak Emirates Military Hospital Rawalpindi, from Dec 2016 to Dec 2017. Methodology: Non-duplicate 84 isolates of Methicillin resistant Staphylococcus aureus from various clinical specimens were included in the study. All these isolates were screened for susceptibility to glycopeptide by E-strips method (Bio mérieux) as well as Agar Dilution method, using vancomycin concentrations of 0.25, 0.50, 1.00, 2.00, 4.00 and 8.00µgm/ml respectively in two fold serial dilutions. Results: There was an overall agreement on 83 samples by both the methods i.e. 83 were Vancomycin SensitiveStaphylococcus aureus by both methods while one isolate with intermediate resistance to Vancomycin was onlydetected by Agar Dilution. The sensitivity of the E–strips compared to Agar Dilution was found to be 100%. Thepositive predictive value was 98.8% with a diagnostic accuracy of 98.8%. Specificity and negative predictive valuecould not be ascertained for E-strips because of the limitation of the method to detect the Vancomycin Intermediate Staphylococcus aureus isolates. Conclusion: E-strip can be a convenient alternative to the gold standard Agar Dilution but its inability to identifyVISA challenges its reliability in determining the Vancomycin resistance in MRSA isolates.

scholarly journals IDENTIFICATION AND DETECTION OF BIOFILM PRODUCING STAPHYLOCOCCUS AUREUS AND ITS ANTIBIOGRAM ACTIVITIES

2021 ◽  
pp. 150-156
Author(s):  
SAPANA SHARMA ◽  
UPASHANA BHANDARI ◽  
YOGESH OLI ◽  
GANESH BHANDARI ◽  
SUNITA BISTA ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Disk Diffusion ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Methicillin Resistant ◽  
Clinical Specimens ◽  
Biofilm Production ◽  
Diffusion Technique ◽  
Almost All

Objectives: The main aim of this work is to determine the antibiogram profile of biofilm-producing Staphylococcus aureus from various clinical specimens of the patients. Methods: Various bacterial cultures of non-repeated clinical specimens from a total of 3388 patients were determined using standard microbiological and biochemical methods. Results: Out of 3388 only 604 (17.02%) displayed growth positive. A total of 65 (51.58%) S. aureus isolates were recovered, 25 (38.46%) were identified as methicillin-resistant S. aureus (MRSA) by Cefoxitin (30 μg) disk diffusion technique, of which majority were from pus/wound swab 22 (37.29%). The antibiogram of the isolates was analyzed by Kirby-Bauer disk diffusion technique analyzing Linezolid to be the most effective drug with susceptibility of 100% to both MRSA and methicillin-sensitive S. aureus, followed by vancomycin, tigecycline, and tetracycline. In vitro biofilm production by tissue culture plate (TCP) and Congo red agar method detected 52 (80%) and 25 (38.46%) as biofilm producers, respectively. TCP identified 2 (3.07%), 7 (10.76%), and 44 (67.69%) as strongly, moderately, and weakly adherent. About 30.7% of MRSA obtained were positive biofilm producers. The minimum inhibitory concentration value of Oxacillin for S. aureus by agar dilution method ranged from 0.025 μg/mL to 128 μg/mL. Conclusion: This study shows that biofilm production was more in methicillin-resistant strains and displayed a high degree of resistance to almost all groups of antibiotics.

scholarly journals Emergence of Vancomycin Resistant Staphylococcus aureus during Hospital Admission at a Tertiary Care Hospital in Bangladesh

2017 ◽  
Vol 3 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Shahana Khanam ◽  
Jalaluddin Ashraful Haq ◽  
SM Shamsuzzaman ◽  
Md Motlabur Rahman ◽  
Kazi Zulfiquer Mamun
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Tertiary Care ◽  
Control Measures ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Care Hospital ◽  
Medical College ◽  
Nasal Swab Sample ◽  
Vancomycin Resistant

Background: Glycopeptides such as vancomycin are frequently the choice of antibiotics for the treatment of infections caused by methicillin resistant Staphylococcus aureus (MRSA). For the last 7 years incidence of vancomycin intermediate S. aureus and vancomycin resistant S. aureus (VISA and VRSA respectively) has been increasing in various parts of the world.Objective: The present study was carried out to find out the presence of VISA and VRSA among isolated MRSA strains.Methodology: This cross sectional study was carried out in the Department of Microbiology in Dhaka medical college during period of January 2010 to December 2011. All S. aureus isolates were screened to detect methicillin resistance and then all MRSA isolates were subjected for MIC testing against vancomycin and oxacillin by agar dilution method, disc diffusion testing and PCR for mecA and pvl genes detection.Result: A total 112 S. aureus were isolated from 500 nasal swab sample collected from adult patients who were admitted in various departments and wards in Dhaka Medical College Hospital. Among 38 MRSA strains out of 112 Staph aureus isolates 3(7.89%) strains were resistance to vancomycin of which 2(5.26%) strains had MIC > 256 mg/mL and one strain had MIC 256mg/mL. All vancomycin resistance strains had MIC of oxacillin > 256 mg/mL. All isolates possess mec-A gene.Conclusion: The present study reveals that emergence of VRSA upon admission at a tertiary care of hospital in Bangladesh. Continuous efforts should be made to prevent the spread and the emergence of VRSA by early detection of the resistant strains and using the proper infection control measures in the hospital setting.Bangladesh Journal of Infectious Diseases 2016;3(1):11-16

Treatment of Infection and Colonization Caused by Methicillin-Resistant Staphylococcus aureus

1991 ◽  
Vol 12 (01) ◽  
pp. 29-35 ◽  
Author(s):  
Henry F. Chambers
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Active Agent ◽  
Methicillin Resistant ◽  
Drug Of Choice ◽  
Serious Infections ◽  
Combination Regimens ◽  
Higher Doses

AbstractThe mechanism of methicillin resistance confers resistance to all available B-lactam antibiotics; consequently, B-lactam antibiotics have no role in therapy of methicillin-resistant Staphylococcus aureus (MRSA) infections. Vancomycin remains the drug of choice. Teicoplanin and daptomycin are two investigational antibiotics related to vancomycin in structure and in spectrum of activity. In clinical trials employing relatively low doses, neither was as effective as vancomycin. Trials at higher doses are on-going. Quinolones, ciprofloxacin in particular, have been used successfully to treat infections caused by MRSA; however, the usefulness of quinolones may be limited by the tendency of resistance to emerge during therapy. Quinolones probably should be used only in combination with another active agent, such as rifampin, when treating serious infections caused by MRSA. Other agents may be active in vitro against MRSA, but clinical data showing their effectiveness are lacking. Rifampin combination regimens appear most effectively to eradicate colonization with MRSA.

scholarly journals Importance of penicillinase production for activity of penicillin alone or in combination with sulbactam in experimental endocarditis due to methicillin-resistant Staphylococcus aureus.

1996 ◽  
Vol 40 (5) ◽  
pp. 1219-1224 ◽  
Author(s):  
B Fantin ◽  
J Pierre ◽  
N Castéla-Papin ◽  
L Saint-Julien ◽  
H Drugeon ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Body Weight ◽  
Synergistic Effect ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Limiting Factor ◽  
High Dose ◽  
Methicillin Resistant

The activity of penicillin, alone and in combination with sulbactam, against a heterogeneously methicillin-resistant, penicillinase-producing clinical isolate of Staphylococcus aureus and its penicillinase-negative derivative was investigated in vitro and in a rabbit experimental endocarditis model. Penicillin was significantly more effective than vancomycin against the penicillinase-negative derivative in vivo (P < 0.001), and it sterilized 25% of the vegetations. The combination of penicillin and sulbactam exhibited an in vivo synergistic effect on the penicillinase-producing strain (P < 0.01) but did not produce any advantage over treatment with vancomycin, even when a high dose of sulbactam was used (100 mg/kg of body weight every 6 h). This combination was significantly less effective against the penicillinase-producing strain than was penicillin alone against the penicillinase-negative derivative (P < 0.03). In addition, the most resistant subpopulation of the surviving bacteria, which grew on agar containing 16 micrograms of methicillin per ml, was detected in 5 of 6 animals treated with penicillin and a high dose of sulbactam against the penicillinase-producing strain compared with only 1 of 12 animals treated with penicillin alone against the penicillinase-negative derivative (P < 0.01). We conclude that penicillin is highly effective against penicillinase-negative methicillin-resistant S. aureus and that penicillinase production, rather than methicillin resistance, appears to be the limiting factor for the activity of the penicillin-sulbactam combination against penicillinase-producing, methicillin-resistant S. aureus.

scholarly journals Susceptibility of community associated methicillin resistant Staphylococcus aureus isolated from faeces to antiseptics

2011 ◽  
Vol 6 (04) ◽  
pp. 317-323 ◽  
Author(s):  
Ezekiel Olugbenga Akinkunmi ◽  
Adebayo Lamikanra
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Property A ◽  
Biochemical Tests ◽  
Methicillin Resistant ◽  
Diffusion Technique ◽  
Significant Difference ◽  
Agar Dilution

Introduction: The study aimed to investigate the resistance of methicillin resistant Staphylococcus aureus (MRSA), an indicator used in hospitals but isolated from faecal samples of children in the community, to commonly used antibiotics and antiseptic agents. Methodology: S. aureus isolates were identified by phenotypic and genotypic techniques such as biochemical tests and polymerase chain reaction. Antibiotic susceptibility was investigated using the disc diffusion technique while the agar dilution method was used to determine the minimum inhibitory concentration (MIC) of antiseptics. Results: MRSA showed considerably higher resistance to other antibiotics than methicillin sensitive Staphylococcus aureus (MSSA). Twelve percent of the MSSA were susceptible to all the antibiotics studied while none of the MRSA had this property. A significant difference in susceptibility between MRSA and MSSA to the three antiseptic agents was observed as 68.8%, 75.0% and 100% of MRSA were less susceptible to benzalkonium chloride, chlorhexidine and cetrimide respectively, while 32.0%, 28.0% and 56.0% of MSSA respectively were less susceptible to these agents compared with S. aureus NCTC 6571. Overall, the MICs for the antiseptics were 2-3 times greater in the MRSA than in the MSSA (p < 0.001). Conclusion: Results show that the concentration of antiseptics used in the prevention of the transmission of infectious agents may have to be raised to cope with the possible presence of MRSA in patients coming into hospital.

scholarly journals In Vitro Antimicrobial Activity of Tigecycline

2015 ◽  
Vol 13 (2) ◽  
pp. 35-38
Author(s):  
Sabita Bhatta ◽  
Babli Basu ◽  
Chandrasekhar Narharrao Chaudhary ◽  
Ashok Kumar Praharaj
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Susceptibility ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Klebsiella Pneumonia ◽  
Methicillin Resistant ◽  
Agar Dilution ◽  
Vancomycin Resistant

Introduction: Tigecycline is a novel glycylcycline  derivative of the tetracycline with activity against a wide range of  organisms including Methicillin resistant Staphylococcus aureus, Vancomycin  resistant  Enterococcus , Extended spectrum beta lactamase   producing  (Escherichia coli , Klebsiella  pneumonia)  and Acinetobacter species.  The aim of the study was to assess effectiveness of the drug against methicillin resistant Staphylococcus aureus (MRSA), vancomycin resistant enterococci (VRE), ESBL producers and carbapenem resistant Acinetobacter baumannii and to compare the efficacy of different methods of antimicrobial susceptibility testing for Tigecycline.Methods: A total of 250 clinical isolates were processed and identified by conventional methods. In all the 250 isolates, antimicrobial susceptibility was carried out by disc diffusion method , Minimum inhibitory test by agar dilution method (MIC) and in 30 isolates of A baumannii  MIC was also done by E test.Results: Out of 250 isolates, 236 isolates were sensitive to tigecycline by agar dilution method while only 159 were sensitive by disk diffusion method.Conclusion: Marked discordance was observed between the results of two different methods (DDT & Agar dilution method) for E coli, Klebsiella spp and A baumannii, where significant number of isolates were resistant to tigecycline by DDT as compared to AD method. But results of MIC by agar dilution method & E test were in concordance for A. baumannii.

scholarly journals Phytochemical analysis, antibacterial activity of hydromethanol extracts from stems of Ximenia americana, Côte d’Ivoire species on methicillin-resistant Staphylococcus aureus

2021 ◽  
Vol 14 (9) ◽  
pp. 3429-3440
Author(s):  
Baudelaire Affi Kakou ◽  
Anoubile Benie ◽  
Alain Hugues N’Guessan ◽  
Konan K. Fernique ◽  
N.K. Guessennd ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Public Health Problem ◽  
Antibacterial Activities ◽  
Dilution Method ◽  
Phytochemical Analysis ◽  
Methicillin Resistant ◽  
Ximenia Americana

The emergence of bacteria resistant to several families of antibiotics is nowadays a public health problem in the world. To overcome this, it appeared necessary to explore sources of active molecules from natural substances. Thus, the objective of this study was to carry out the phytochemical sorting of hydromethanol extracts from Ximenia americana stems and to evaluate their antibacterial activities on the in-vitro growth of methicillin-resistant Staphylococcus aureus. The phytochemical screening performed allowed us to identify saponins, sterols and polyterpenes, polyphenols, tannins and flavonoids. HPLC-MS/MS analysis lead to the identification of a variety of flavan-3ol, quercetin and derivatives. The study of antibacterial activity carried out on 5 multi-resistant clinical strains and on a reference strain by the Muller-Hinton agar medium diffusion and dilution method showed that the extracts were active on all the strains with MICs ranging from 6.25 to 100 mg and MBCs ranging from 12.5 to 100 mg. The antibacterial potential of these extracts highlighted in this study could make this plant a candidate for in-depth investigations that could lead to the discovery of new antibacterial molecules. L’apparition de bactéries résistantes à plusieurs familles d’antibiotiques constitue, de nos jours, un problème de santé publique dans le monde. Pour y remédier, l’exploration de sources de molécules actives à partir des substances naturelles s’est avérée nécessaire. Ainsi, l’objectif de cette étude était de réaliser le tri phytochimique des extraits hydrométhanoliques de tiges de Ximenia americana et d’évaluer leurs activités antibactériennes sur la croissance in-vitro des Staphylococcus aureus résistant à la méticilline. Le screening phytochimique réalisé a permis d’identifier des saponines, des stérols et polyterpènes, des polyphénols, des tanins et des flavonoïdes. L’analyse à la HPLC-MS/MS a permis d’identifier une variété de flavan-3ol, de la quercétine et dérivées. L’étude de l’activité antibactérienne réalisée sur 5 souches cliniques multirésistantes et sur une souche de référence par la méthode de diffusion et de dilution en milieu gélosé Muller-Hinton a montré que les extraits étaient actifs sur toutes les souches avec des CMI variant de 6,25 à 100 mg et des CMB variant de 12,5 à 100 mg. Le potentiel antibactérien de ces extraits mis en évidence dans cette étude pourrait faire de cette plante une candidate à des investigations approfondies pouvant aboutir à la découverte de nouvelles molécules antibactériennes.

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