Co-detection of Group A Streptococcus and Viruses in Children with Pharyngitis (original) (raw)
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Novelty in Biomedicine, 2015
Background: Streptococcus group B (GBS) or Streptococcus agalactiae is typically associated with neonatal disease and infection in pregnant women. Mortality of GBS sepsis in neonates is over 50% and is particularly high in preterm infants. GBS also causes invasive infection in pregnant and non-pregnant women including urinary tract infection (UTI). Penicillin-derived antibiotics remained as choice drugs for treatment of GBS infection; however, Erythromycin and Clindamycin are useful in cases of allergic to Penicillin. The aim of this study was to investigate the resistance to Erythromycin and Clindamycin, especially inducible Clindamycin resistance, in GBS isolated from urinary samples of women who attended medical offices in Tehran, Iran. Materials and Methods: This study was conducted on 5000 urine samples from Jan. 2011 to Oct. 2012 that 104 GBS were isolated. The isolates were identified as GBS using laboratory criteria. Antimicrobial susceptibility test was done by Erythromycin disk 15µg and Clindamycin disk 2µg for observation inducible resistant D-zone test by double-disk diffusion method with Erythromycin and adjacent Clindamycin. Results: Among the 5000 urine samples 104 (2.08%) were Beta hemolytic GBS. Of the 104 isolated GBS, 22 (21.2%) were resistance, 24 (23%) were intermediate, and 58 (55.8%) were susceptible to Erythromycin; however, 24 (23%) were resistance, 5 (4.8%) were intermediate, and 75 (72.2%) were susceptible to Clindamycin. Of the 22 Erythromycin-resistant isolates, 10 (9.5% in total GBS isolated) displayed the D zone; it means they have inducible Erythromycin resistant to Clindamycin. Conclusion: Various studies in other countries report lower rates of inducible Clindamycin resistance; it indicates the use of more macrolides in the treatment of UTI.
Zentralblatt für Bakteriologie : international journal of medical microbiology, 1998
248 Strains of group A beta-haemolytic streptococci (GABHS) were tested against penicillin and the macrolide antibiotics, erythromycin, clarithromycin and azithromycin. 213 (85.9%) GABHS isolates were taken from throat swabs from patients with pharyngotonsillitis, 35 isolates (14.1%) were from other body sites or from invasive infections. The age of the patients ranged from 9 months to 89 years, 155 of the patients (62.5%) were below 10 years of age. The results of the E-test method and a disk diffusion assay were compared; to classify the phenotype of the erythromycin-resistant strains, a disk induction test was carried out. None of the 248 GABHS strains showed resistance to penicillin, whereas 53 GABHS isolates (21.4%) were resistant to the macrolide antibiotics included in the test. There were only minor discrepancies between the two testing methods. The MIC data obtained with the E-test method suggested that among the macrolides, erythromycin and clarithromycin had slightly high...
Susceptibility of Various Serogroups of Streptococci to Clindamycin and Lincomycin
Antimicrobial Agents and Chemotherapy, 1975
The minimal inhibitory concentration of lincomycin and clindamycin for a large number of strains from multiple serogroups of streptococci was determined. The median minimal inhibitory concentration for streptococci from groups A, B, C, F, G, H, L, and M and nongroupable organisms ranged from 0.02 to 0.39 μg of lincomycin per ml and from ≤0.01 to 0.09 μg of clindamycin per ml. Among the group D strains, Streptococcus faecium and Streptococcus faecalis were resistant to lincomycin and clindamycin, whereas Streptococcus bovis and four American strains of Streptococcus durans resembled nongroup D isolates in their susceptibility to these agents. Occasional strains of nongroup D streptococci were highly resistant to lincomycin and clindamycin.
Objective: This study was undertaken to assess the frequency of the phenotypic expression of the inducible resistance to clindamycin which was due to the expression of the erm genes in various clinical isolates of the Staphylococcus species. Materials and Methods: This was a cross sectional study conducted in the Dept. of Microbiology and Immunology, Veer Chandra Singh Garhwali Govt. Medical Sciences and Research Institute, Srikot, Uttarakhand, from July 2010 to December 2011. A total of 373 consecutive, non duplicate strains of Staphylococci isolated from various clinical samples like pus, wound swab, blood, urine and other body uids, were tested. The isolates which had a discordant resistance pattern (clindamycin-sensitive and erythromycin-resistant) by Kirby Bauer Disk Diffusion method were selected and subjected to the D-test for inducible clindamycin resistance, as per the Clinical and Laboratory Standards Institutes (CLSI) guidelines. Results: Amongthe373clinicalisolatesofStaphylococciwhich were studied, 134 isolates showed a discordant resistance pat- tern. Among these discordant strains, 45 (33.6%) isolates were D-test positive, which had inducible clindamycin resistance and belonged to the inducible macrolide lincosamide strepto- gramin-B phenotype (MLSBi). 89 (66.4%) isolates were D-test negative and they belonged to the macrolide streptogramin phenotype (MS). Among the MLSBi phenotypes, 6 (13.3%) iso- lates were methicillin-resistant Staphylococcus aureus (MRSA), 13 (28.9%) were Methicillin-sensitive S.aureus (MSSA) and 26 (57.8%) were coagulase negative staphylococci (CONS). Conclusion: The D-test is a simple, effective and an important method for the phenotypic detection of inducible clindamycin resistance and it should be used routinely, as it will help in guiding the empirical therapy. The possible clinical failures can thus be avoided.
A prospective study to determine the prevalent bacterial isolates of neonatal sepsis their antimicrobial susceptibility and prevalence of inducible clindamycin resistance (ICR) in these isolates in P.. Newborns with clinical signs of septicemia and positive blood culture during twelve months were prospectively studied. Identification and antimicrobial susceptibility of blood culture isolates were studied. Three hundred fortyseven isolates from the total of 1462 blood cultures were screened for septicaemia.Coagulase negative staphylococcus (CoNS) was the most common (22.19%) cause of sepsis. Oxacillin (93.5%), co-trimoxazole (88.4%), erythromycin (64.9%) All isolates were susceptible to vancomycin and linezolid. This study demonstrates a simple, reliable method (double-disc diffusion test) for detecting inducible resistance to clindamycin(CLI) in erythromycin-resistance (ER-R) isolates of S. aureus and CoNS. In Staphylococcus aureus, mecA and femA are the genetic determinants of methicillin resistance. \ .
2014
Methicillin resistant Staphylococcus aureus (MRSA) is a well-recognised hospital pathogen. In the recent years, MRSA is increasingly being isolated from the community. Clindamycin is frequently the drug of choice in such isolates. However, use clindamycin in erythromycin resistant Staphylococcus isolates could result in treatment failure as a result of inducible clindamycin resistancein spite of showingin vitro sensitivity. Current study was conducted to detect the presence of inducible clindamycin resistance in erythromycin resistant Staphylococcus isolates by D-zone test,correlate clindamycin resistance phenotypes with minimum inhibitory concentrations (MICs) of clindamycin, erythromycin, oxacillin and vancomycin among the isolates and. correlate various resistance phenotypes with methicillin resistance. One-hundred and fifty non duplicate isolates of Staphylococcus species were identified and antibiotic susceptibility testing was done using Kirby Bauer's disc diffusion method. MICs were determined using E-test for oxacillin, vancomycin,clindamycin and erythromycin using E-test strips (Himedia).Out of150 Staphylococcusclinical isolates, 96 were S.aureus and 54 were coagulase negativeStaphylococci (CONS).About 78 (81.2%) of the S.aureus isolates and 39 (72.2%) of the CONS were found to be methicillin resistant. Inducible clindamycin resistance was reportedin 59 (39.3%) of the isolates, constitutive resistance phenotype in 48% while 12.7% demonstrated MS phenotype.Out of inspected isolates 18 and 11.3% had MICs for clindamycin between 0.01-0.06 µg/mLand 0.06-0.1 respectively. However12.5% had MIC ranging from 4-8 µg/mLand more than half of the isolates(58%) had MIC > 8 µg/mL. Constitutive resistant phenotype (cMLS) was the predominant phenotype in methicillin resistant isolates. MS phenotype was the predominant among MSSA (methicillin sensitive S. aureus) while MSCNS (methicillin sensitive CONS) cMLS (46.7%) predominated.MIC of all erythromycin resistant isolateswere 240 µg/mL. Nearly16.7% of the cMLS and 57.9% of MS isolates were found to be oxacillin sensitive and 83% of iMLS and 83.3% of MS phenotype isolates were oxacillin resistant on MIC testing. 47.2% of cMLS and 73.6% of MS isolates had MIC 2 µg/mL for vancomycin and 52.7% of cMLS and 26.3% of MS isolates had MICs in intermediate range for vancomycin. D-testing might help clinicians to decide whether to use clindamycin in Staphylococcal infectionswhen erythromycin resistance is present. Determination of MICs helps to identify exact sensitivity profile of isolates in cases where clinical failure occurs due to misleading disk diffusion tests.
The pattern of susceptibility to a range of antimicrobials was tested for 1485 isolates of Streptococcus pyogenes and 1547 isolates of Staphylococcus aureus included in the international PROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin) surveillance study (1999)(2000). Overall, almost 10% of S. pyogenes isolates were erythromycin A resistant. There was a wide heterogeneity of resistance, with high levels of macrolide resistance in Poland (42%), Hong Kong (28%), Italy (25%), Portugal (24%) and Spain (21%), and no macrolide resistance in Indonesia, Austria, Belgium, the Netherlands or the UK. Using NCCLS tentative breakpoints, 97.6% of isolates were susceptible to telithromycin, with MIC 90 ≤ 0.015 mg/L in most regions. Resistance among S. pyogenes to the β-lactams (MIC 90 ≤ 0.12 mg/L for all except cefaclor) and fluoroquinolones was not detected. Macrolide resistance was present among the S. aureus isolates, and as with S. pyogenes, there was a wide heterogeneity of resistance, with lower rates in Australia, Indonesia, Hungary, Austria, Germany, the Netherlands, Portugal, Sweden and Switzerland. Methicillin-resistant isolates were resistant to the β-lactams and the macrolides. Resistance to telithromycin was detected in methicillin-resistant isolates in Latin and North America, Asia and Europe. Telithromycin resistance was nonexistent or low (MIC 90 range 0.06-0.25 mg/L) the Netherlands, Portugal, Sweden and Switzerland. Regardless of methicillin susceptibility, resistance to linezolid, teicoplanin or vancomycin was not apparent globally.