SOURCE:

Faculty: Pharmaceutical Sciences
Department: Pharm. Microbio & Biotech

CONTRIBUTORS:

Enwa, F. O.
Esimone, C. O.
Iroha, R. I.

ABSTRACT:

Pneumonia is an acute or chronic infection of one or both of the lungs characterized by swelling of the inner parts (air sacs/alveoli) of the lungs resulting from direct inflammation of the lung tissue. It is a severe form of acute respiratory infection that specifically infects the lungs.This study was aimed at finding the prevalence, pathogenicity and molecular characterization of Staph. aureusisolated from children (1-7years) having pneumonia in Delta, Edo and Bayelsa States, South – South Nigeria. Specific objectives include: investigation of the resistance patternof Staph. aureus isolates in the studied zones;determination of biofilms and enterotoxins produced by the clinical isolates as well as its effect on the lungs;determination of the heamatological and clinical chemistry parameters of the Wistar rats; molecular characterization of methicillin resistance Staph. aureusand also to determine the activities of some selected plants extracts on clinical isolates.A purposive sampling technique was used to collect samples from clinically diagnosed pneumonia subjects over a period of six (6) months. A total of 1,500 sputa were collected from pneumonia subjects from fifteen (15) primary and tertiary hospitals. The isolates were inoculated into Albino Wistar rats for ten (10) days. The isolation and identification of Staph. aureusfrom the pneumoniae subjects were carried out using mannitol salt agar and catalase, oxidase and DNase test. Antimicrobial susceptibility studies were carried out using the Kirby-Bauer disk diffusion technique. Agar well diffusion technique was used to determine the antibacterial activity of the plant extracts. Biofilm detection was carried out using crystal violet binding technique, Enterotoxin detection using reverse passive latex agglutination method for enterotoxin (A, B, C, D and E). Histopathological examination of harvested lungs of Wistar rats stained by Haematoxylin and eosin (H&E) technique;Full blood count, and urea, creatinine, potassium, sodiumwere also analyzed using Sequential Multiple Analyzer and isolates wereevaluated for the presence of plasmid DNA and resistant genes by conventional polymerase chain reaction (PCR).Data were analyzed using Graph pad Instat Demo. A total of 79 (5.3%) sputa sample were positive for Staph. aureus out of the 1500 samples obtained from clinically diagnosed pneumonia subjects following cultural method on mannitol salt agar and other confirmatory biochemical test specific for Staph. aureus. Results of the antibiogram showed that the isolates were mostly resistant to oxacillin and highly susceptible to gentamicin followed by ofloxacin. There was no significant difference between rifampicin,vancomycin, and clindamycinused at P<0.05. The PCR showed no amplification for MRSA. Photomicrograph section of the lungs revealed interstitial pneumonitis with fat vacuole. The prevalence ofenterotoxin showed that enterotoxin B was the most prevalentin all centres except Irrua Specialist hospital in Edo state that had enterotoxin C. Ethanol extract of Curcuma longahad MIC of 30.37mg/ml while Zingiberofficinalehadminimum inhibitory concentration (MIC) of 394.92mg/ml.Allium sativumhad MIC of 274.22mg/ml. One of the isolates was resistant to all extracts used except ethanol extract of Curcuma longa.This study showed that the prevalence ofStaph. aureusinpneumonia patients in Edo, Delta and Bayelsa states is low. The biofilm forming capacity of Staph. aureusisolates is high and the most prevalent Staph. aureus enterotoxins in the selected study area is Enterotoxin B. These findings thereforesuggest, monitoring of the virulence and resistance patterns of Staph.aureusin pneumonia subjects in the study area.