METHODS: MSCs and Oh-LAAO were isolated and characterized by standard methodologies. The effects of the experimental therapies were evaluated in C57/BL6 mice. The animal study groups consisted of full-thickness uninfected and MRSA-infected wound models which received Oh-LAAO, MSCs, or both. Oh-LAAO was administered directly on the wound while MSCs were delivered via intradermal injections. The animals were housed individually with wound measurements taken on days 0, 3, and 7. Histological analyses and bacterial enumeration were performed on wound biopsies to determine the efficacy of each treatment.
RESULTS: Immunophenotyping and differentiation assays conducted on isolated MSCs indicated expression of standard cell surface markers and plasticity which corresponds to published data. Characterization of Oh-LAAO by proteomics, enzymatic, and antibacterial assays confirmed the identity, purity, and functionality of the enzyme prior to use in our subsequent studies. Individual treatments with MSCs and Oh-LAAO in the infected model resulted in reduction of MRSA load by one order of magnitude to the approximate range of 6 log10 colony-forming units (CFU) compared to untreated controls (7.3 log10 CFU). Similar wound healing and improvements in histological parameters were observed between the two groups. Co-administration of MSCs and Oh-LAAO reduced bacterial burden by approximately two orders of magnitude to 5.1 log10 CFU. Wound closure measurements and histology analysis of biopsies obtained from the combinational therapy group indicated significant enhancement in the wound healing process compared to all other groups.
CONCLUSIONS: We demonstrated that co-administration of MSCs and Oh-LAAO into a mouse model of MRSA-infected wounds exhibited a synergistic antibacterial effect which significantly reduced the bacterial count and accelerated the wound healing process.
METHODS: A retrospective review was performed on children with orbital cellulitis aged below 18 years who were admitted to Hospital Universiti Sains Malaysia, Kelantan, Malaysia, between January 2013 and December 2017.
RESULTS: A total of 14 paediatric patients fulfilling the diagnostic criteria for orbital cellulitis were included. Their mean age was 6.5 ± 1.2 years. Boys were more likely to have orbital cellulitis than girls (71.4% vs. 28.6%). Involvement of both eyes was observed in 14.3% of the patients. Sinusitis (28.6%) and upper respiratory tract infection (21.4%) were the most common predisposing causes. Staphylococcus aureus (28.6%) was the leading pathogen. Longer duration of hospitalisation was observed in those infected with methicillin-resistant Staphylococcus aureus and Burkholderia pseudomallei. 10 (71.4%) patients were treated with a combination of two or three antibiotics. In this series, 42.9% had surgical interventions.
CONCLUSION: Young boys were found to be more commonly affected by orbital cellulitis than young girls. Staphylococcus aureus was the most common isolated microorganism. Methicillin-resistant Staphylococcus aureus and Burkholderia pseudomallei caused severe infection. Sinusitis and upper respiratory tract infection were the most common predisposing factors. A majority of the children improved with medical treatment alone. Our findings are in slight disagreement with other published reports on paediatric orbital cellulitis, especially from the Asian region.
METHODS: Polymerase chain reaction (PCR) was used to detect the presence of sasX, qacA/B and mupA genes from 47 paired MRSA isolates. A paired isolate was defined as one nasal swab (colonising) isolate and clinical isolate that caused infection in the same patient. 22 selected paired isolates were subjected to multilocus sequence typing (MLST). The genetic relatedness among the isolates and association between the putative genes with epidemic sequence types (STs) were investigated.
RESULTS: 7 (14.9%, n = 14) paired isolates were positive for the sasX gene. qacA/B genes were positive in 7.4% (n = 7) of the isolates, from three paired isolates and one clinical isolate whose paired colonising isolate was negative. The paired sample of three patients were positive for both genes. The mupA gene was not detected in all the isolates. MLST revealed two epidemic STs, ST22 and ST239, and a novel ST4649. sasX and qacA/B genes were found in ST239 in 29.5% (n = 13) and 13.6% (n = 6) of cases, respectively. Gene co-existence occurred in 13.6% (n = 6) of MRSA ST239 and 2.3% (n = 1) of MRSA ST4649.
CONCLUSION: sasX and qacA/B genes were present in the MRSA isolates, while the mupA gene was undetected. ST22 and ST239 were the major MRSA clones. The circulating MRSA genotypes conferred different virulence and resistance determinants in our healthcare settings.