Molecular characterization of methicillin-resistant Staphylococcus aureus isolates from a hospital in Ghana

2Asante, J., 1Govinden, U., 2Owusu-Ofori, A., 3Bester, L., and 1Essack, S. Y.

Abstract

Background: Methicillin-resistant Staphylococcus aureus (MRSA) are a major cause of hospital- and community-acquired infection. They can colonize humans and cause a wide range of infections including pneumonia, endocarditis and bacteraemia. We investigated the molecular mechanism of resistance and virulence of MRSA isolates from a teaching hospital in Ghana. Methodology: A total of 91 S. aureus isolates constituted the initial bacterial sample. Identification of S. aureus was confirmed by the VITEK 2 system. The cefoxitin screen test was used to detect MRSA and antibiotic susceptibility was determined using the VITEK 2 system. The resistance (mecA, blaZ, aac-aph, ermC, and tetK) and virulence (lukS/F-PV, hla, hld and eta) genes were amplified by polymerase chain reaction (PCR) and positive samples subjected to DNA sequencing. Pulsed field gel electrophoresis (PFGE) was used to ascertain the relatedness of the isolates.
Results: Fifty-eight of 91 (63.7%) isolates were putatively methicillin resistant by the phenotypic cefoxitin screen test and oxacillin MICs. However, 43 (47%) of the isolates were genotypically confirmed as MRSA based on PCR detection of the mecA gene. Furthermore, 37.9% of isolates displayed resistance to tetracycline, 19% to trimethoprim-sulphamethoxazole, 15.5% to clindamycin, 12.1% to gentamicin, 13.8% to ciprofloxacin and erythromycin, 6.9% to moxifloxacin and 7.0% to rifampicin. None of the isolates was positive for inducible clindamycin resistance. The prevalence of resistance (mecA, blaZ, aac(6’)-aph(2’’), tetK, and ermC) and virulence (hla and lukS/F-PV) genes respectively were 74%, 33%, 22%, 19%, 3%, 5% and 3%, with isolates organized in two highly related clades. Conclusion: Results indicate a fairly high occurrence of MRSA, which can complicate the effective therapy of S. aureus infections, necessitating surveillance and stringent infection control programmes to forestall its spread.

Keywords: MRSA, mecA, blaZ, hla, lukS/F-PV

Download full journal in PDF below

Molecular characterization of methicillin-resistant Staphylococcus aureus isolates from a hospital in Ghana

Revised April 9, 2019; Accepted April 11, 2019
Copyright 2019 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.

Prevalence of sulfate reducing bacteria in oral cavity: a narrative review

U Gopalakrishnan, A.S. Felicita, L Mahendra, S Premkumar, R Madasamy

 

Abstract

Sulphate is used as terminal electron acceptor for the respiration of sulphate reducing bacteria (SRB) forming a specialized group of microbes. SRB have been known to cause microbiologically induced corrosion by forming metallic sulfides and oxides in the process of their dissimilatory respiration. Since oral cavity provides a conducive environment for corrosion, presence of SRB in oral cavity and their corrosive potential needs to be assessed. This article provides a narrative review of the available literature with the primary objective of evaluating the presence of SRB in oral cavity of patients.

Keywords: SRB; corrosion, oral cavity, patients

Download full journal in PDF below

Prevalence of sulfate reducing bacteria in oral cavity a narrative review

Histopathological studies on kidney and liver of albino rat infected with toxigenic Aspergillus flavus after treatment with isolated Lactobacillus species from Kunu

O.O. Olonisakin, C.O. Ogidi, Y.A. Jeff-Agboola, B.J. Akinyele

 

Abstract

Background: Aflatoxin is a metabolic product of Aspergillus flavus that causes several injuries to vital organs in the body.

Methods: The liver and kidney tissue of healthy rats challenged with toxigenic A. flavus after treatment with Lactobacillus plantarum and Lactobacillus delbrueckii were examined.

Results: The weight of the liver (3.61 g) and kidney (11.33 g) of infected rats with toxigenic mould were significantly reduced (P<0.05) when compared to the group treated with Lactobacillus spp.; BD+AP+LP, BD+AP+LD and BD+ AP+LPD. The rats fed basal diet and Lactobacillusspp. have a normal histological structure. Necrotic lesions, thickening of the glomerular basement membrane and collapse of the glomerulus were observed in the liver and kidney of rats induced with A. flavus. The rats infected with Lactobacillus spp. regained their strength and activity after treatment but showed mild necrosis in the liver and thickening of glomerular basement in the kidney.

Conclusions: The use of Lactobacillus species suppressed the growth and eliminated the potential risk of toxigenic A. flavus in the infected rats. This showed that Lactobacillus spp. possess some therapeutic properties due to their ability to secret secondary metabolites. The bioactive compounds can be exploited and used in food products to inhibit the growth of food borne pathogens.

Keywords: Aflatoxins, Lactic Acid Bacteria, Bio-control, Fermented beverage

Download full journal in PDF below

Histopathological studies on kidney and liver of albino rat infected with toxigenic Aspergillus flavus after treatment with isolated Lactobacillus species from Kunu