MALDI-TOF MS Based Identification and Characterization of Staphylococci Isolates from Human and Animal Sources

Chijioke A. Nsofor1*, Chibuzor M. Nsofor2, Nnamdi C.D. Ukwandu1, Achim J. Kaasch3
1Department of Biotechnology, Federal University of Technology Owerri, Imo State Nigeria
2Department of Medical Laboratory Science, Madonna University Teaching Hospital Elele, Rivers State Nigeria
3Institute of Medical Microbiology and Hospital Hygiene, Faculty of Medicine, Heinrich Heine University Düsseldorf, Düsseldorf, Germany

Corresponding Author: [email protected]; Tel: +23408038783955
Recieved Date: 13 June 2021; Accepted Date: 23 August; Published Date: 03 September
Citation: Nsofor CA, Nsofor CM, Ukwandu NCD, Kaasch AJ. MALDI-TOF MS Based Identification and Characterization of Staphylococci Isolates from Human and Animal Sources. Trop J Nat Prod Res. 2021; 5(8):1515-1520.
© 2021 Nsofor et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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Identification of microorganisms usually depends on phenotypic typing and culture which may not give proper identification. The aim of this study is to use matrix-assisted desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) technique to accurately identify Staphylococci isolates from human and animal specimens; preliminarily identified by conventional microbiological techniques. Among the 112 preliminarily identified staphylococci isolates, MALDI-TOF MS showed that 23(20.5%) were Staphylococcus aureus while 89 (79.5%) were coagulase-negative staphylococci (CoNS). The identified CoNS were Staphylococcus sciuri, 56 (50.0%), Staphylococcus haemolyticus 7 (6.3%), Staphylococcus cohnii 5 (4.5%), Staphylococcus arlettae 1 (0.9%), Staphylococcus simulans 12 (10.7%), Staphylococcus gallinarum 6 (5.4%), Staphylococcus lentus 1 (0.9%) and Staphylococcus piscifermentans 1 (0.9%). S. haemolyticus, S. cohnii and S. arlettae were identified only from human specimens while S. lentus and S. piscifermentans were identified only from poultry specimens. All the identified staphylococci were susceptible to fosfomycin and imipenem, however, a very high rate of resistance was seen in oxacillin and benzyipenicillin; 82.6% and 95.7% for S. aureus; 61.8% and 78.7% for CoNS respectively. A total of 15(65.2%) of the identified S. aureus were positive for mecA gene while the 4(17.4%) that were PVL-positive did not harbour the mecA gene. The spa typing revealed that the stains were genetically diverse with the detection of nine different spa types from the 23 S. aureus strains. The findings from this study have shown that MALDI-TOF MS is a powerfully useful tool for accurate identification of Staphylococci to the species level.

Keywords: MALDI-TOF MS, Staphylococci, Antibiotic Resistance, spa typing, Molecular characterization.
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ISSN: 2616-0684 (Print)
ISSN: 2616-0692 (Online)
DOI: 10.26538/tjnpr
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