S. aureus – afrjcem.org

¹*Abouelnour, A., ²Zaki, M. E.,³Hassan R., and⁴Elkannishy, S. M. H.
^1,2Department of Clinical Pathology, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt
³Department of Medical Microbiology, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt
⁴Department of Toxicology, Mansoura Hospital, Mansoura University, Mansoura 35516, Egypt
⁴Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Tabuk, Tabuk, 71491, Saudi Arabia
Correspondence to: aalaa_abo@yahoo.com

Abstract:

Background: Clindamycin has been a good alternative drug to penicillins in the treatment of infections caused by Staphylococcus aureus but resistance to this agent has led to therapeutic failure. Inducible clindamycin resistance in staphylococci carrying erm genes may not be detectable by routine disk diffusion test. The objective of this study is to phenotypically detect clindamycin resistance in clinical S. aureus isolates and determine the prevalence of ermA, ermB and ermC carriage among these isolates.
Methodology: A total of 230 non-duplicate S. aureus were isolated from children admitted to Mansoura University Children Hospital during the period January 2016 and June 2017 by conventional microbiology method. Invitro antibiotic susceptibility to selected antibiotics including erythromycin was performed by the disk diffusion technique. The „D-zone‟ test was used to phenotypically detect inducible clindamycin resistance. The presence of ermA, ermB and ermC genes was confirmed by multiplex polymerase chain reaction (m-PCR) assay. Results: One hundred and seven (46.6%) isolates were phenotypically resistant to erythromycin while 109 (47.3%) were methicillin (cefoxitin) resistant S. aureus (MRSA). The macrolide-lincosamin-streptograminB (MLSB) phenotypes among the erythromycin resistant isolates were 47 (44%) inducible MLSB and 46 (43%) constitutive MLSB, while 14 (13.0%) were MS phenotype. Although, the MLSB phenotype was more predominant in MRSA (n=60, 56.1%) than MSSA (n=33, 30.7%) while the MS phenotype was more predominant in MSSA (n=9, 8.4%) than MRSA (n=5, 4.6%) isolates, the difference was not statistically significant (p=0.0777). The ermA (29.0%, n=31) and ermC (18.7%, n=20) were the most prevalent genes carried by the isolates while ermB was carried by a few (4.7%, n=5). Forty six (43%) isolates did not carry any detectable erm gene.
Conclusion: In this study, both inducible and constitutive clindamycin resistance phenotypes were common among S. aureus isolates. Although the genetic basis for this may be attributed to carriage of ermA, ermB and ermC genes, a number of the resistant isolates did not carry any of these genes.

Keywords: phenotypic, genotypic, macrolide-lincosamide-streptogramin B, S. aureus, children
Received July 20, 2019; Revised September 22, 2019; Accepted September 28, 2019
Copyright 2020 AJCEM Open Access. This article is licensed and distributed under the terms of the Creative Commons Attrition 4.0 International License (//creativecommmons.org/licenses/by/4.0), which permits unrestricted use, distribution and reproduction in any medium, provided credit is given to the original author(s) and the source.

Identification phénotypique et génotypique de Staphylococcus aureus résistant à la clindamycine à l’Hôpital Universitaire Mansoura, Egypte

¹*Abouelnour, A., ²Zaki, M. E., ³Hassan R., et ⁴Elkannishy, S. M. H.
^1,2Département de pathologie clinique, Faculté de médecine, université Mansoura, Mansoura 35516, Égypte
³Département de microbiologie médicale, Faculté de médecine, université Mansoura, Mansoura 35516, Égypte 4ème département de toxicologie, hôpital Mansoura, université Mansoura, Mansoura 35516, Égypte
⁴Département 3D de pharmacologie et de toxicologie, faculté de pharmacie, université de Tabuk, Tabuk, 71491, Arabie saoudite
Correspondance à: aalaa_abo@yahoo.com

Abstrait:

Contexte: La clindamycine était un bon médicament alternatif aux pénicillines dans le traitement des infections causées par Staphylococcus aureus, mais la résistance à cet agent a entraîné un échec thérapeutique. La résistance inductible à la clindamycine chez les staphylocoques porteurs du gène erm peut ne pas être détectable par le test de diffusion systématique sur disque. L’objectif de cette étude est de détecter phénotypiquement la résistance à la clindamycine dans les isolats cliniques de S. aureus et de déterminer la prévalence du portage d’ermA, d’ermB et d’ermC parmi ces isolats. sélection d‟antibiotiques, notamment à l‟érythromycine, a été réalisée par la technique de diffusion sur disque. Le test de la «zone D» a été utilisé pour détecter phénotypiquement la résistance inductible à la clindamycine. La présence des gènes ermA, ermB et ermC a été confirmée par un test de réaction en chaîne de la polymérase multiplexe (m-PCR).
Résultats: Cent sept isolats (46,6%) étaient phénotypiquement résistants à l’érythromycine, tandis que 109 (47,3%) étaient résistants à la méthicilline (céfoxitine) S. aureus (MRSA). Les phénotypes macrolide-lincosamin-streptogramine B (MLSB) parmi les isolats résistants à l’érythromycine étaient 47 (44%) MLSB inductibles et 46 (43%) MLSB constitutifs, alors que 14 (13,0%) étaient des phénotypes MS. Bien que le phénotype MLSB soit plus prédominant dans le SARM (n=60, 56,1%) que le MSSA (n=33, 30,7%), le phénotype MS était plus prédominant dans le MSSA (n=9, 8,4%) que le SARM (n=5, 4,6%), la différence n’était pas statistiquement significative (p=0,0777). ErmA (29,0%, n=31) et ermC (18,7%, n=20) étaient les gènes les plus prévalents portés par les isolats, tandis que ermB était porté par quelques-uns (4,7%, n=5). Quarante-six (43%) isolats ne portaient aucun erm gène détectable.
Conclusion: Dans cette étude, les phénotypes de résistance à la clindamycine tant inductibles que constitutifs étaient courants parmi les isolats de S. aureus. Bien que la base génétique de ceci puisse être attribuée au portage des gènes ermA, ermB et ermC, un certain nombre des isolats résistants ne portaient aucun de ces gènes.

Clindamycin resistant S. aureus in Egypt Afr. J. Clin. Exper. Microbiol. 2020; 21 (1): 30 – 35

Mots-clés: phénotypique, génotypique, macrolide-lincosamide-streptogramine B, S. aureus, enfants

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Phenotypic and genotypic identification of Staphylococcus aureus resistant to clindamycin in Mansoura University Children Hospital, Egypt

A.M. Andrianarivelo, T.H. Andriamandimbisoa, L.M. Rakotondraoelina, A.B.A. Ratsimbazafy, F.E. Razafimanantsoa, A.A. Raharisoa, C Rafalimanana, A Rasamindrakotroka

Abstract

Introduction: On contact of antibiotics, S. aureus has gradually acquired multiple antibiotic resistances, including the methicillin (MRSA) and without lose its virulence. The aim of the present study was to report the evolution of resistance of S. aureus to different common antibiotics and to determine the antibiotics active against MRSA.

Materials and methods: This is a retrospective and descriptive study for 10 years from January 2005 to December 2014 at the Laboratory of Microbiology of the HU-JRA Antananarivo, the biggest academic hospital located in the capital of Madagascar. All demands for standard bacteriological examination were registered in the laboratory for various bacteriological exams or from samples taken from hospitalized patients and we included all positive cultures for S. aureus. The variables selected and used for the study were community or nosocomial sources of patients and results of susceptibility testing.

Results: A total of 906 results from 282 (31.12%) community-acquired and 624 (68.88%) nosocomial infections were studied an average of 100±25strains by year of study. Overall, the prevalence of MRSA was 13.83% (39 of 282 isolates)for community-acquired strains, and 15.70% (98 of 624) for nosocomial infections (p> 0.05)with a total of 29.53%. Resistance rate to trimethoprim-sulfamethoxazole was significantly higher in nosocomial infection than in community-acquired. No significant difference was observed in other antibiotics. Of the 137 MRSA, except vancomycin, fusidic acid is the antibiotic that worked the most in 114 cases (83.21%) followed by gentamicin in 96 cases (70.07%). Apart from ciprofloxacin and tetracycline that we have noticed an increase in resistance rates in 2012 and 2013, almost all antibiotics tested have a stable rate of resistance.

Conclusion: The antibiotics tested showed extremely high rates of resistance and that the problem of antibiotic resistance in S. aureus is effective in our center.

Keywords: Resistance, antibiotics, S. aureus , HU-JRA ,Antananarivo

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Status of resistance to antimicrobial agents of Staphylococcus aureus strains at the laboratory of microbiology of the HU-JRA Antananarivo