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Molecular detection of antimicrobial resistance genes in multidrug-resistant Gram-negative bacteria isolated from clinical samples in two hospitals in Niger

*1Abdoulaye, O., 2Abdoulaye, I., 3Alassane Halawen, M., 4Ibrahim Mamadou, A. K., 1,5Maman Sani Falissou, S., 5,6Adamou Amatagas, S., 1Boureima, H., 2Boubacar Issaka, B., 2Ide, H., 7Yacouba, A., 1,5Sidi Maman Bacha, B., 3Chaibou, S., 2Hamadou, I., 1Harouna Amadou, M. L., 2Ousmane, S., 5Doutchi, M., and 7Mamadou, S.

1Faculté des Sciences de la Santé, Université de Dan Dicko Dankoulodo de Maradi, BP 465, Niger

2Centre de Recherche Médicale et Sanitaire, Niamey, Niger

3Hôpital Général de Référence de Niamey, Niger

4Centre Hospitalier Régional de Dosso, Niger

5Hôpital National de Zinder, Niger

6Faculté des Sciences de la Santé, Université André Salifou de Zinder, Niger

7Faculté des Sciences de la Santé, Université Abdou Moumouni, Niamey, Niger

*Correspondence to: ousmaneabdoulaye2010@yahoo.com; Cel: (+227) 96354580

Abstract:
Background: According to the World Health Organization (WHO), bacterial resistance to antibiotics is a global public health challenge, which is also developing in Niger. The aim of this study was to determine the prevalence of antibiotic resistance genes in Gram-negative bacilli isolated from clinical samples in the biological laboratories of two selected health facilities in Niger. Continue reading “Molecular detection of antimicrobial resistance genes in multidrug-resistant Gram-negative bacteria isolated from clinical samples in two hospitals in Niger”

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Polymerase chain reaction detection of haemolysin D gene (hlyD) in uropathogenic Escherichia coli as a novel diagnostic test for urinary tract infection

[1]Abubakar, N. H., [2]Aliyu, M., *[3]Jibril, M., and 2Mohammed, Y.

1Kano State Secondary Schools Management Board, Kano, Nigeria                     

2Department of Medical Microbiology and Parasitology, Faculty of Clinical Sciences, College of Health Sciences Bayero University, Kano, Nigeria

3Department of Pharmacology and Therapeutics, Faculty of Pharmaceutical Sciences, College of Natural and Pharmaceutical Sciences, Bayero University, Kano, Nigeria

*Correspondence to: murtalamj@yahoo.com; +2348034453990; ORCID: 0000-0003-2554-5552

 

Abstract:

 Background:  Urinary tract infection (UTI) is a common and sometime serious infectious disease diagnosed using conventional urine culture as the ‘gold standard’ for identifying Escherichia coli, the most common causative agent. However, due to the slow turn-around-time and other challenges of urine culture, this study explores the use of a novel biomolecular polymerase chain reaction (PCR) approach to detect the presence of haemolysin D gene (hlyD) that encodes a unique virulence factor of uropathogenic E. coli (UPEC) for its rapid identification in UTI.

Methodology: Primers from UPEC CFT073 and non-pathogenic E. coli K-12 MG1655 strains provided by Nottingham Trent University, England, UK were used to investigate the presence of haemolysin D gene (hlyD) in UPEC. The hlyD primers were developed from hlyD with locus number C_RS01660 on UPEC CFT073 strain using the NCBI, virulence finder, and Island viewer, and used in a PCR assay to target the hlyD in UPEC. Three sets of PCR templates were designed (UPEC, E. coli, and “No template”), each with internal and external controls amplified in a multiplex PCR assay, and agarose gel electrophoresis was used to separate the amplicons, and determine the specificity of hlyD for UPEC. Continue reading “Polymerase chain reaction detection of haemolysin D gene (hlyD) in uropathogenic Escherichia coli as a novel diagnostic test for urinary tract infection”

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Phenotypic and genotypic characterization of plasmid-mediated AmpC beta-lactamases in enteric Gram-negative bacteria from patients with lower respiratory tract infections in a tertiary hospital, southwest Nigeria

*1,2Thonda, O. A., 2Oluduro, A. O., 3Adewole, O. O., and 4Obiajunwa, P. O.
*1Department of Biological Sciences, Microbiology Unit, Kings University, Odeomu, Nigeria

2Department of Microbiology, Faculty of Science, OAU, Ile-Ife, Nigeria
3Department of Medicine, College of Health Sciences, OAU, Ile-Ife, Nigeria
4Department of Paediatrics and Child Heath, Faculty of Clinical Sciences, OAU, Ile-Ife, Nigeria

Correspondence to: thondakemi22@gmail.com

Abstract:
Background: AmpC or class C or group 1 beta lactamases are class C cephalosporinases that hydrolyse a wide variety of beta-lactam antibiotics including alpha methoxy beta-lactams (cefoxitin), narrow and broad spectrum cephalosporins. This study was conducted to characterize plasmid-mediated AmpC producing enteric Gram- negative bacteria from patients with lower respiratory tract infections in Obafemi Awolowo University Teaching Hospital Complex (OAUTHC) Ile Ife, Osun State, Nigeria

Methodology: A total of 149 patients with clinical features of lower respiratory tract infections (LRTI) were selected by simple random sampling for the study. All Gram-negative isolates recovered from standard microbiological cultures of respiratory specimens of these patients were tested against cefoxitin, third generation cephalosporins (3GCs), and other antibiotics using the disc diffusion AST method, and also screened for production of AmpC beta-lactamases phenotypically by the CLSI method. Plasmid DNA extraction was carried out on twenty-nine cefoxitin-resistant selected isolates using the Kado and Lin method, while genotypic detection of plasmid-mediated AmpC gene was carried out by the polymerase chain reaction (PCR) assay. Continue reading “Phenotypic and genotypic characterization of plasmid-mediated AmpC beta-lactamases in enteric Gram-negative bacteria from patients with lower respiratory tract infections in a tertiary hospital, southwest Nigeria”

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Non-tuberculous mycobacteria isolated from patients with suspected tuberculosis in Abidjan, Ivory Coast

*1,2Ouassa, T., 1N’Guessan-Kacou, M. S., and 2Kouakou, K. A.

1Centre for Diagnosis and Research on AIDS and other Infectious Diseases (CeDReS), University Hospital of Treichville, Abidjan

2Department of Bacteriology-Virology, Faculty of Pharmacy, University Félix Houphouët-Boigny, Abidjan

*Correspondence to: timothee.ouassa@cedres.org; timouassa@yahoo.fr; 0022521258459; 0022502500078

Abstract:

Background: Apart from tuberculosis caused by Mycobacterium tuberculosis complex (MTBc) species, there are many other mycobacterial infections due to nontuberculous mycobacteria (NTM). These are rarely identified in many low resource settings in Africa because of the lack of accurate identification methods. The aim of the study is to identify NTM species involved in respiratory infections in Abidjan, Ivory Coast. Continue reading “Non-tuberculous mycobacteria isolated from patients with suspected tuberculosis in Abidjan, Ivory Coast”

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Klebsiella pneumoniae producing extended spectrum β-lactamase in Regional Military University Hospital of Oran, Algeria: antibiotic resistance, biofilm formation, and detection of blaCTX-M and blaTEM genes

*1Benbrahim, C., 1Barka, M. S., 2Benmahdi, L., 3Zatout, A., and 1Khadir, A.

1Laboratory of Applied Microbiology in Food, Biomedical and Environment (LAMAABE), Department of Biology, Faculty of Nature and Life, Earth and Universal Sciences, Abou Bekr Belkaid University, 13000 Tlemcen, Algeria

2Laboratory of Microbiology, Regional Military University Hospital, Oran, Algeria

3Laboratory of Microbiology and Plant Biology, Department of Biological Sciences, Faculty of Natural Sciences and Life, University of Abdlhamid Ibn Badis, Mostaganem, Algeria

*Correspondence to: chahla.benbrahim@univ-tlemcen.dz

Abstract:
Background: Klebsiella pneumoniae is a bacterial pathogen commonly associated with severe nosocomial and community acquired infections especially through the acquisition of extended spectrum β-lactamases (ESβL) and biofilm formation capacity. The objectives of this study are to determine the prevalence of K. pneumoniae ESβL (KP-ESβL)-producing isolates in the Regional Military University Hospital of Oran (HMRUO) Algeria, characterize their antibiotic resistance profile, genetically detect blaTEM and blaCTX-M genes, and evaluate their biofilm formation capacity. Continue reading “Klebsiella pneumoniae producing extended spectrum β-lactamase in Regional Military University Hospital of Oran, Algeria: antibiotic resistance, biofilm formation, and detection of blaCTX-M and blaTEM genes”

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Antifungal susceptibility and detection of mutant ERG11 gene in vaginal Candida isolates in University of Uyo Teaching Hospital, Uyo, Nigeria

Ikenyi, C. L., *Ekuma, A. E., and Atting, I. A.

Department of Medical Microbiology and Parasitology, University of Uyo, Uyo, Nigeria

*Correspondence to: agantemekuma@uniuyo.edu.ng; +2348023075572

Abstract:
Background: Candida vulvovaginitis is an important cause of morbidity among women. Fluconazole and other azoles are among the commonest antifungal agents used for the treatment of this condition. Azole resistance among Candida species is an increasing problem, and mutations in the ERG11 gene is the commonest cause of fluconazole resistance in Candida. The objectives of this study are to determine antifungal susceptibility of vaginal Candida isolates and detect carriage of mutant ERG11 gene by them.

Methods: High vaginal swabs obtained from 260 participants were cultured on Saboraud’s Dextrose agar (SDA) for isolation of Candida, and identified by growth on CHROMagar Candida, germ tube and carbohydrate fermentation tests. Antifungal susceptibility to fluconazole, voriconazole, nystatin and flucytosine was determined by the Kirby Bauer disc diffusion method on supplemented Mueller Hinton agar. ERG11 gene was detected by conventional singleplex polymerase chain reaction (PCR) assay.

Results: Candida was isolated from 126 of 260 (48.5%) participants, and the identified species were Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilopsis and Candida famata. There were 112 (88.9%) isolates susceptible to fluconazole, 122 (96.8%) to voriconazole, 111 (88.1%) to nystatin, and 16 (6.6%) to flucytosine. The mutant ERG11 gene was detected in all four fluconazole-resistant isolates but not from any of five randomly selected fluconazole susceptible dose dependent (SDD) isolates.

Conclusion: Azole resistance among Candida in this environment is associated with mutant ERG11 gene expression.

Keywords: antifungi, fluconazole, Candida, ERG11, PCR

Received March 6, 2020; Revised April 22, 2020; Accepted April 24, 2020

Copyright 2020 AJCEM Open Access. This article is licensed and distributed under the terms of the Creative Commons Attrition 4.0 International License <a rel=”license” href=”//creativecommons.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.

Sensibilité antifongique et détection du gène ERG11 mutant dans des isolats vaginaux de Candida à l’hôpital universitaire de Uyo, Uyo, Nigéria

Ikenyi, C. L., *Ekuma, A. E., et Atting, I. A.
Département de microbiologie médicale et de parasitologie, Université d’Uyo, Uyo, Nigéria *Correspondance à: agantemekuma@uniuyo.edu.ng; +2348023075572

Abstrait:
Contexte: La vulvovaginite à Candida est une cause importante de morbidité chez les femmes. Le fluconazole et d’autres azoles sont parmi les agents antifongiques les plus couramment utilisés pour le traitement de cette condition. La résistance à l’azole chez les espèces de Candida est un problème croissant, et les mutations du gène ERG11 sont la cause la plus fréquente de résistance au fluconazole chez Candida. Les objectifs de cette étude sont de déterminer la sensibilité antifongique des isolats vaginaux de Candida et de détecter le transport du gène ERG11 mutant par eux.

Méthodes: Des écouvillons vaginaux élevés obtenus auprès de 260 participants ont été cultivés sur gélose Dextrose de Saboraud (SDA) pour l’isolement de Candida, et identifiés par croissance sur CHROMagar Candida, tube germinatif et tests de fermentation des glucides. La sensibilité antifongique au fluconazole, au voriconazole, à la nystatine et à la flucytosine a été déterminée par la méthode de diffusion sur disque de Kirby Bauer sur de la gélose Mueller Hinton complétée. Le gène ERG11 a été détecté par un test classique de réaction en chaîne par polymérase (PCR).

Résultats: Candida a été isolé sur 126 des 260 participants (48,5%), et les espèces identifiées étaient Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilopsis et Candida famata. Il y avait 112 (88,9%) isolats sensibles au fluconazole, 122 (96,8%) au voriconazole, 111 (88,1%) à la nystatine et 16 (6,6%) à la flucytosine. Le gène ERG11 mutant a été détecté dans les quatre isolats résistants au fluconazole, mais pas dans aucun des cinq isolats dépendants de la dose (SDD) sensibles au fluconazole sélectionnés au hasard.

Conclusion: la résistance à l’azole chez Candida dans cet environnement est associée à l’expression du gène ERG11 mutant.

Mots-clés: antifongiques, fluconazole, Candida, ERG11, PCR

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Antifungal susceptibility and detection of mutant ERG11 gene in vaginal Candida isolates in University of Uyo Teaching Hospital, Uyo, Nigeria

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Genotypic identification of coliforms isolated from cases of subclinical mastitis among pastoral herds in parts of Kaduna State, Nigeria

1, 2*Makolo, D., 2Suleiman, A. B., 2Olonitola, O. S., 3Bello, M., and 4Ahmadu, I.

1Department of Sciences, School of Preliminary Studies, Kogi State Polytechnic, Lokoja, Nigeria

2Department of Microbiology, Faculty of Life Sciences, Ahmadu Bello University, Zaria, Nigeria

3Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, Ahmadu Bello University, Zaria, Nigeria

4National Tuberculosis Reference Laboratory, Zaria, Nigeria *Correspondence to: makolodaniel@gmail.com

Abstract:

Background: Mastitis caused by Staphylococcus aureus was initially considered the major problem in dairy herds, but over the last few decades, the incidence of coliform mastitis has increased among the pastoral herds in Nigeria due to poor environmental and milking hygiene. Hence, this study was aimed at genotypic identification of coliform bacteria isolated from cases of bovine mastitis among pastoral herds in parts of Kaduna State, Nigeria.

Methods: A cross-sectional survey of 30 herds of cows across 7 Local Government Areas of Kaduna State, Nigeria, was conducted. One hundred and forty seven cows were proportionately selected by purposive sampling technique. The milk samples were aseptically collected and bacteriologically screened for coliform bacteria following standard bacteriological techniques. Nine out of 12 coliforms identified phenotypically were selected for PCR amplification and sequencing of their 16S rRNA gene. The Basic Local Alignment Search Tool (BLAST) analysis of the sequences obtained was done on the National Centre for Biotechnology Information (NCBI) data base, and isolates confirmed based on similarity to 16S rDNA sequences in the Gen Bank Continue reading “Genotypic identification of coliforms isolated from cases of subclinical mastitis among pastoral herds in parts of Kaduna State, Nigeria”

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Fungal neonatal and infantile sepsis in Egypt: risk factors and identification of fungal isolates

1*Ahmed, S. H., 2Mokhtar, E. M., 3El-Kholy, I. M., 4El Essawy, A. K., 1El-Din, A. A., and 1Shetaia, Y. M.
1Microbiology Department, Faculty of Science, Ain Shams University, Cairo, Egypt 2Microbiology Department, Abou Al-azayem Hospital, Cairo, Egypt 3Clinical Pathology Department, Ain Shams University Specialized Hospital, Ain Shams University, Cairo, Egypt 4Microbiology Department, Ain Shams University Specialized Hospital, Ain Shams University Cairo, Egypt, *Correspondence to: sara_saifelnasr@hotmail.com; 00971563993304

Abstract:

Background: Invasive fungal diseases (IFDs) are opportunistic infections associated with significant mortality in paediatric patients, especially in those with compromised immune system and neonates with very low birth weight (VLBW). The objectives of this study are to determine the prevalence, clinical features and fungi isolates of neonatal sepsis in three hospitals in Egypt. Methodology: The study is a cross sectional survey of 176 neonates with clinical sepsis admitted to the neonatal intensive care units (NICU) of the three hospitals over a period of one year (February 2015 to January 2016). A minimum of two blood samples (collected within 24 hours) from each neonate were cultured for bacteria in automated BacT/AlerT and conventional culture bottles, while Saboraud-Brain Heart Infusion broth was inoculated for fungi culture. Positive growths from the broth were sub-cultured on Sabouraud Dextrose Agar (SDA) plates for aerobic incubation at 25oC and 37oC for 2 weeks. Identification of fungi colonies on SDA was by conventional morphology and confirmation on chromogenic agar media. Phylogenetic analysis of representative fungi isolates was done by partial nucleotide sequencing of D1-D2 domain of the large subunit rRNA gene.
Results: Of the 176 neonates, blood culture was positive for pathogens in 55 (31.3 %) samples and fungi were isolated in 26 (14.8 %); yeast (25) and mould (1). The commonly isolated yeasts were Candida albicans, Candida tropicalis, and Candida krusei representing 34.6%, 30.8% and 23.1%, respectively of the total fungi isolated. The phylogenetic analysis in comparison to Genbank data showed defined clades for Candida tropicalis, Candida parapsilosis, Candida albicans and Pichia kudriavzevii
Conclusion: This current study highlights the changing pattern of neonatal infections in Egypt caused by Candida, with increasing incidence of infections caused by non-albicans Candida species.

Key words: fungal infection, neonatal, risk factors, PCR, yeast

Received July 4, 2019; Revised September 16, 2019; Accepted September 18, 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.

Infection fongique néonatale et infantile en Égypte: facteurs de risque et identification des isolats fongiques

1*Ahmed, S. H., 2Mokhtar, E. M., 3El-Kholy, I. M., 4El Essawy, A. K., 1El-Din, A. A., et 1Shetaia, Y. M.
1Département de microbiologie, Faculté des sciences, Université Ain Shams, Le Caire, Égypte
2Département de microbiologie, Hôpital Abou Al-Azayem, Le Caire, Égypte
3Département de pathologie clinique, Hôpital spécialisé de l’Université Ain Shams, Université Ain Shams,
Le Caire, Égypte
4Département de microbiologie, Université de Ain Shams, Spécialisé Hôpital, Université Ain Shams,
Le Caire, Égypte
*Correspondance à: sara_saifelnasr@hotmail.com; 00971563993304

Abstrait:

Contexte: Les maladies fongiques invasives (IFD) sont des infections opportunistes associées à une mortalité significative chez les patients pédiatriques, en particulier ceux dont le système immunitaire est compromis et les nouveau-nés de très faible poids à la naissance (VLBW). Les objectifs de cette étude sont de déterminer la prévalence, les caractéristiques cliniques et les isolements fongiques de la sepsie néonatale dans trois hôpitaux en Égypte.
Méthodologie: L’étude est une enquête transversale menée auprès de 176 nouveau-nés présentant une septicémie clinique et admis dans les unités de soins intensifs néonatals des trois hôpitaux sur une période d’un an (de février 2015 à janvier 2016). Un minimum de deux échantillons de sang (recueillis dans les 24 heures) de chaque nouveau-né ont été cultivés pour la bactérie dans des flacons de culture automatisés BacT/AlerT et conventionnels, tandis que le bouillon Saboraud-Brain Heart Infusion a été inoculé pour la culture de champignons. Les croissances positives du bouillon ont été sous-cultivées sur des plaques de gélose Sabouraud Dextrose Agar (SDA) pour une incubation aérobie à 25°C et à 37°C pendant 2 semaines. L’identification des colonies de champignons sur la SDA a été réalisée par la morphologie conventionnelle et confirmée sur un milieu chromogène en gélose. L’analyse phylogénétique d’isolats de champignons représentatifs a été réalisée par séquençage partiel de nucléotides du domaine D1-D2 du gène de l’ARNr de grande sous-unité.
Résultats: Sur les 176 nouveau-nés, la culture de sang était positive pour les agents pathogènes dans 55 échantillons (31,3%) et les champignons ont été isolés dans 26 (14,8%); levure (25) et moisissure (1). Les levures communément isolées étaient Candida albicans, Candida tropicalis et Candida krusei, représentant respectivement 34,6%, 30,8% et 23,1% du total des champignons isolés. L’analyse phylogénétique comparée aux données de Genbank a montré des clades définis pour Candida tropicalis, Candida parapsilosis, Candida albicans et Pichia kudriavzevii
Conclusion: La présente étude met en évidence l’évolution du schéma des infections néonatales causées par Candida en Égypte, avec une incidence croissante des infections causées par des espèces de Candida non albicans.

Afr. J. Clin. Exper. Microbiol. Fungal neonatal and infantile sepsis 2020; 21 (1): 14 – 20

Mots-clés: infection fongique, néonatale, facteurs de risque, PCR, levure

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Fungal neonatal and infantile sepsis in Egypt: risk factors and identification of fungal isolates

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Coagulase negative staphylococci in Anti-Cancer Center, Batna, Algeria: antibiotic resistance pattern, biofilm formation, and detection of mecA and icaAD genes

1*Zatout, A., 2Djibaoui, R., 2Kassah-Laouar, A., and 3Benbrahim, C.
1Laboratory of Microbiology and Plant Biology, Department of Biological Sciences, Faculty of Natural Sciences and Life, University of Abdlhamid Ibn Badis, Mostaganem, Algeria
2Central Laboratory of Biology, Anticancer Center of Batna, Algeria
3Laboratory of Microbiology Applied to the Agroalimentary Biomedical and the Environment, Department of Biology, Faculty of Natural Sciences and Life, University Abou BekrBelkaid, Tlemcen, Algeria
*Correspondence to: asma.zatout@univ-mosta.dz

Abstract:
Background: Coagulase-negative staphylococci (CoNS) are normal microbial flora found on the skin and mucous membranes of mammals. Considered for a long time as avirulent commensals, these bacteria are now recognized as opportunistic pathogens by virtue of their high resistance to multiple antibiotics and capacity for biofilm formations, which made them important agents of nosocomial and community-acquired infections. The objectives of this study are to determine the antibiotic resistance pattern and biofilm formation, and to detect mecA and icaAD genes in clinical CoNS isolates from Batna’s Anti-Cancer Center (ACC) in Algeria. Methods: A total of 66 CoNS were isolated from different samples and identified by API Staph system. In vitro antibiotic susceptibility testing (AST) of each isolate to selected antibiotics was determined by the disk diffusion method, and minimum inhibitory concentrations (MICs) of oxacillin and vancomycin were determined by E-test. Biofilm formation was assessed by Tissue Culture Plate (TCP) and Congo Red Agar (CRA) methods. The polymerase chain reaction (PCR) was used to amplify mecA gene in 9 oxacillin-resistant and 1 oxacillin-sensitive CoNS, and icaAD gene in 9 biofilm forming and 1 non-biofilm forming CoNS. Sequencing of the 16S rDNA of 1 mecA and 1 icaAD positive isolates was performed by the Sanger method. Results: Nine species of CoNS were identified, with Staphylococcus epidermidis (n=29, 44%) and Staphylococcus haemolyticus (n=15, 22.7%) constituting the largest proportion, and isolated mainly from the onco-haematology service unit of the center. The isolates were resistant to penicillin G (98.5%), cefoxitin (80.3%) and oxacillin (72.2%). The TCP method was more sensitive (89.4%) than CRA method (31.8%) in detecting biofilm formation. The mecA gene was detected in 66.7% (6/9) of oxacillin resistant CoNS and the icaAD gene in 55.6% (5/9) of TCP positive CoNS isolates Conclusion: Invitro resistance to methicillin (oxacillin) and biofilm formation were high among the CoNS isolates in this study, but the association of these with respective carriage of mecA and icaAD genes was low.

Keywords: Coagulase negative staphylococci, identification, antibiotic resistance, biofilm, PCR

Received April 26, 2019; Revised October 2, 2019; Accepted October 5, 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.

Staphylocoques à coagulase négative au Centre Anti-Cancer du Batna, Algérie: résistance aux antibiotiques, formation de biofilms et détection des gènes mecA et icaAD

1*Zatout, A., 2Djibaoui, R., 2Kassah-Laouar, A., et 3Benbrahim, C.
1Laboratoire de Microbiologie et Biologie Végétale, Département des Sciences Biologiques, Faculté des Sciences de la Nature et de la Vie, Université Abdlhamid Ibn Badis, Mostaganem, Algérie
2Laboratoire Central de Biologie, Centre Anti-Cancer (ACC), Batna, Algérie
3laboratoire de Microbiologie Appliquée à l’Agroalimentaire au Biomédical et à l’Environnement, Département de Biologie, Faculté des Sciences de la Nature et de la Vie, Université Abou Bekr Belkaid, Tlemcen, Algérie
Correspondance à: asma.zatout@univ-mosta.dz
Coagulase negative staphylococci in Algeria Afr J. Clin. Exper. Microbiol. 2020; 21 (1): 21-29

Abstrait :

Contexte: Les staphylocoques à coagulase négative (CoNS) sont une flore microbienne normale présente sur la peau et les muqueuses humaines des mammifères. Considérés depuis longtemps comme des commensales avirulentes, ces bactéries sont reconnues comme agents pathogènes opportunistes grâce à leurs multiples propriétés coexistantes de résistance aux antibiotiques et de formation de biofilms qui constituent des agents importants d’infections nosocomiales et communautaires. l’objectif de cette étude est de déterminer la résistance aux antibiotiques, la formation de biofilms et pour rechercher des gènes mecA et icaAD dans les isolats cliniques de staphylocoques à coagulase négative du Centre Anti-Cancer (AAC) de Batna en Algérie. Méthodes: au total de 66 des SCN ont été isolés de différents prélèvements et identifiés par galerie API Staph. Le test de sensibilité aux antibiotiques In vitro de chaque isolat par rapport aux antibiotiques sélectionnés a été déterminé par la méthode de diffusion sur disque, et les concentrations minimales inhibitrices (MICs) de l’oxacilline et de la vancomycine ont été déterminées par E-test. La formation de biofilm a été évaluée par la méthode de culture de tissu en plaque (TCP) et la méthode de Rouge Congo Agar (CRA). La réaction en chaîne par polymérase (PCR) a été utilisée pour amplifier l’ADN du gène mecA dont 9 des SCN résistants à l’oxacilline et 1 sensible à l’oxacilline et le gène icaAD dont 9 des SCN formant biofilm et 1 non-formant biofilm. Le séquençage de l’ADNr 16S des isolats positifs, 1 mecA et 1 icaAD ont été réalisés par la méthode de Sanger. Résultats: Neuf espèces des SCN ont été identifiées avec Staphylococcus epidermidis (n=29, 44%) et Staphylococcus haemolyticus (n=15, 22,7%) constituant la plus grande proportion, et isolées principalement de l’unité de service d’onco-hématologie du centre. Les isolats étaient résistants à la pénicilline G (98,5%), à la céfoxitine (80,3%) et à l’oxacilline (72,2%). La méthode TCP était plus sensible (89,4%) que la méthode CRA (31,8%) dans la détection de la formation de biofilm. Le gène mecA a été détecté dans 66,7% (6/9) des SCN résistants à l’oxacilline et le gène icaAD dans 55,6% (5/9) des isolats positifs des SCN pour CRA. Conclusion: La résistance à la méthicilline (oxacilline) in vitro et la formation de biofilms étaient élevées chez les isolats des SCN de cette étude, mais leur corrélation avec le portage respectif des gènes mecA et icaAD était faible.

Mots-clés: Staphylocoque à coagulase négative, identification, résistance aux antibiotiques, biofilm, PCR

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Coagulase negative staphylococci in Anti-Cancer Center, Batna, Algeria: antibiotic resistance pattern, biofilm formation, and detection of mecA and icaAD genes

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Non detection of mecA gene in methicillin resistant Staphylococcus aureus isolates from pigs

C.N. Nwaogaraku, S.I. Smith, J.A. Badaki

 

Abstract

Background: Methicillin resistant Staphylococcus aureus (MRSA) have become a global health problem causing infections in both humans and livestock, ranging from skin and soft tissue to life threatening blood stream infections. The mecA gene is known to confer resistance to MRSA isolates. This study investigated the carriage of mecA gene by MRSA isolates from pigs.

Methods: One hundred non duplicate staphylococcal isolates recovered from blood samples of pigs in Bariga district of Lagos State at the Molecular Biology and Biotechnology unit of the Nigerian Institute of Medical Research were used in the study. S. aureus was identified by cultural characteristics, and positive catalase, coagulase and deoxyribonuclease tests. Phenotypic methicillin resistance was determined by the modified Kirby Bauer disk diffusion method and mecA gene was detected by conventional polymerase chain reaction (PCR) assay.

Results: Twenty-five S. aureus were identified, of which 11 (44%) were MRSA by phenotypic method. All the isolates were mecA negative on PCR.

Conclusion: The MRSA phenotype observed in the pig isolates in this study appears not to be the classical mecA mediated resistance. There may be alternative mechanisms of resistance in MRSA isolates in pigs.

Keywords: MRSA, phenotypic, mecA gene, PCR, pigs

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Non detection of mecA gene in methicillin resistant Staphylococcus aureus isolates from pigs