Predominance of Acinetobacter spp., Harboring the blaIMP Gene, Contaminating the Hospital Environment in a Tertiary Hospital in Mwanza, Tanzania: A Cross-Sectional Laboratory-Based Study

Vitus Silago; Eveline C Mruma; Betrand Msemwa; Conjester I Mtemisika; Shukurani Phillip; Reuben A Ndagula; Maria M Said; Martha F Mushi; Stephen E Mshana

doi:10.3390/pathogens11010063

Predominance of Acinetobacter spp., Harboring the bla_IMP Gene, Contaminating the Hospital Environment in a Tertiary Hospital in Mwanza, Tanzania: A Cross-Sectional Laboratory-Based Study

Pathogens. 2022 Jan 4;11(1):63. doi: 10.3390/pathogens11010063.

Authors

Vitus Silago¹, Eveline C Mruma¹, Betrand Msemwa¹, Conjester I Mtemisika^{1

2}, Shukurani Phillip^{1

3}, Reuben A Ndagula⁴, Maria M Said^{1

5}, Martha F Mushi¹, Stephen E Mshana¹

Affiliations

¹ Department of Microbiology and Immunology, Weill Bugando School of Medicine, Catholic University of Health and Allied Sciences, Mwanza P.O. Box 1464, Tanzania.
² Molecular Biology Department, Central Pathology Laboratory, Bugando Medical Centre, Mwanza P.O. Box 1370, Tanzania.
³ Institute of Allied Health Sciences, Ruaha Catholic University, Iringa P.O. Box 774, Tanzania.
⁴ National Public Health Laboratory, Dar es Salaam P.O. Box 9083, Tanzania.
⁵ Department of Clinical Laboratory, Kondoa District Hospital, Dodoma P.O. Box 40, Tanzania.

Abstract

Data on colonization and hospital contamination of carbapenem-resistant Gram-negative bacteria (CR-GNB) are limited in low- and middle-income countries. We designed this study to determine the prevalence and co-existence of carbapenemase genes among CR-GNB isolated from clinical, colonization, and hospital environmental samples at a tertiary hospital in Mwanza, Tanzania. The modified Hodge test (MHT), the combined disk test (CDT), and the double-disk synergy test (DDST) were used for the phenotypic detection of carbapenemases. A multiplex PCR assay was used to detect bla_IMP and bla_KPC, and a singleplex PCR assay was used to detect bla_OXA-48. Data were analyzed by STATA version 13.0. Overall, 68.8% (44/64) of the CR-GNB had at least one phenotype by phenotypic methods, whereby 60.9% (39/64) were both CDT and DDST positive and 31.3% (20/64) were MHT positive. A total of 23/64 (35.9%) had at least one of the genes tested with the predominance of bla_IMP (91.3%; 21/23). In addition, 47.7% (21/44) of the CR-GNB phenotypes had at least one gene. Around 47.8% (11/23) of the CR-GNB carried multiple genes encoding for carbapenem resistance, with the maximum co-existence of bla_IMP/bla_KPC/bla_OXA-48 (45.5%; 5/11). The majority of carbapenem-resistant genes were detected in Acinetobacter spp. (82.6%; 19/23) and isolated from bed swabs (69.6%; 16/23). Acinetobacter spp. carrying the bla_IMP gene predominantly contaminated the hospital environment. Therefore, we recommend routine decontamination of inanimate hospital surfaces, including patient beds.

Keywords: Gram-negative bacteria; Mwanza; antimicrobial resistance; carbapenem resistance; carbapenemase genes; combination disk test; double-disk synergy test; modified Hodge test.