Molecular Epidemiology of Carbapenem-resistant Acinetobacter baumannii Isolates in a Senegalese University Teaching Hospital
Gora Lo *
Laboratoire de Bactériologie-Virologie, Centre Hospitalier National Universitaire (CHNU) Aristide Le Dantec, Dakar, Sénégal and Institut de Recherche en Santé, de Surveillance Epidémiologique et de Formation (IRESSEF), Dakar, Sénégal.
Assane Dieng
Laboratoire de Bactériologie-Virologie, Centre Hospitalier National Universitaire (CHNU) Aristide Le Dantec, Dakar, Sénégal.
Awa Ba-Diallo
Laboratoire de Bactériologie-Virologie, Centre Hospitalier National Universitaire (CHNU) Aristide Le Dantec, Dakar, Sénégal and Institut de Recherche en Santé, de Surveillance Epidémiologique et de Formation (IRESSEF), Dakar, Sénégal.
Marieme Samb
Laboratoire de Bactériologie-Virologie, Centre Hospitalier National Universitaire (CHNU) Aristide Le Dantec, Dakar, Sénégal.
Alioune Tine
Laboratoire de Bactériologie-Virologie, Centre Hospitalier National Universitaire (CHNU) Aristide Le Dantec, Dakar, Sénégal.
Serigne Mbaye Lo Ndiaye
Laboratoire de Bactériologie-Virologie, Centre Hospitalier National Universitaire (CHNU) Aristide Le Dantec, Dakar, Sénégal.
Farba Karam
Laboratoire de Bactériologie-Virologie, Centre Hospitalier National Universitaire (CHNU) Aristide Le Dantec, Dakar, Sénégal.
Habsa Diagne-Samb
Laboratoire de Bactériologie-Virologie, Centre Hospitalier National Universitaire (CHNU) Aristide Le Dantec, Dakar, Sénégal.
Safietou Ngom-Cisse
Laboratoire de Bactériologie-Virologie, Centre Hospitalier National Universitaire (CHNU) Aristide Le Dantec, Dakar, Sénégal.
Aissatou Sow Ndoye
Laboratoire de Bactériologie-Virologie, Centre Hospitalier National Universitaire (CHNU) Aristide Le Dantec, Dakar, Sénégal and Institut de Recherche en Santé, de Surveillance Epidémiologique et de Formation (IRESSEF), Dakar, Sénégal.
Halimatou Diop-Ndiaye
Laboratoire de Bactériologie-Virologie, Centre Hospitalier National Universitaire (CHNU) Aristide Le Dantec, Dakar, Sénégal and Institut de Recherche en Santé, de Surveillance Epidémiologique et de Formation (IRESSEF), Dakar, Sénégal.
Coumba Toure-Kane
Institut de Recherche en Santé, de Surveillance Epidémiologique et de Formation (IRESSEF), Dakar, Sénégal.
Aïssatou Gaye-Diallo
Laboratoire de Bactériologie-Virologie, Centre Hospitalier National Universitaire (CHNU) Aristide Le Dantec, Dakar, Sénégal and Institut de Recherche en Santé, de Surveillance Epidémiologique et de Formation (IRESSEF), Dakar, Sénégal.
Souleymane Mboup
Laboratoire de Bactériologie-Virologie, Centre Hospitalier National Universitaire (CHNU) Aristide Le Dantec, Dakar, Sénégal and Institut de Recherche en Santé, de Surveillance Epidémiologique et de Formation (IRESSEF), Dakar, Sénégal.
Cheikh Saad Bouh Boye
Laboratoire de Bactériologie-Virologie, Centre Hospitalier National Universitaire (CHNU) Aristide Le Dantec, Dakar, Sénégal.
Makhtar Camara
Laboratoire de Bactériologie-Virologie, Centre Hospitalier National Universitaire (CHNU) Aristide Le Dantec, Dakar, Sénégal and Institut de Recherche en Santé, de Surveillance Epidémiologique et de Formation (IRESSEF), Dakar, Sénégal.
*Author to whom correspondence should be addressed.
Abstract
Background: The emergence and spread of carbapenem-resistant Acinetobacter baumannii are critical in hospitals, particularly in intensive care units (ICUs), which represents a public health concern worldwide. In this study, we investigated the molecular epidemiology of multi-drug resistant A. baumannii (MDR-AB) in Dakar, Senegal.
Methods. The A. baumannii was isolated from Eosin Methylene Blue Agar culture and identified using API 20NE strip test and MALDI-TOF. The antimicrobial susceptibility testing was performed using the disk diffusion method. Simplex and multiplex-polymerase chain reactions with appropriate primers were used to detect and sequence the following β-lactamase genes: Two class D carbapenem hydrolyzing oxacillinases (blaOXA-51 and blaOXA-23), three class B metallo-β-lactamase genes (blaIMP, blaVIM and blaNDM), and five class A β-lactamase genes (blaPER, blaSHV, blaVEB, blaTEM, and blaGES).
Results: A total of 29 strains of MDR-AB were isolated from patients hospitalized at Aristide Le Dantec University teaching hospital in Dakar, Senegal. Among the 29 MDR-AB strains isolated, 11 (37.9%) were isolated from ICUs, 5 (17.2%) from pediatric surgery, and 13 (44.8%) from other departments. The MDR strains were isolated from urine and pus samples with 12 (41.4%) and 9 (31.0%), respectively. All isolates were positive for the A. baumannii specific gene blaOXA-51. The blaOXA-51 and blaOXA-23 genes coexisted in 26 (89.65%) of the strains. The blaIMP and blaVIM genes were not detected among the selected strains. Moreover1 (3.4%) strain elicited the gene coding for metallo-β-lactamase NDM-1. 2 (6.9%) isolates turned out to produce the penicillinase TEM-2.
Conclusions: Carbapenem resistance in Senegalese strains of A. baumannii is predominantly due to the worldwide disseminated gene blaOXA-23, with a subset of strains due to NDM-1 and TEM-2. Systemic molecular surveillance network should be established for further efficient monitoring of MDR strains in Senegal.
Keywords: Acinetobacter baumannii, Carbapenemase, molecular epidemiology, multiplex PCR, NDM-1, TEM-2