Molecular analysis and the toxin, MSCRAMM, and biofilm genes of methicillin-resistant Staphylococcus aureus strains isolated from pemphigus wounds: A study based on SCCmec and dru typing.

INTRODUCTION: Pemphigus is a chronic autoimmune blistering disease. Pemphigus blisters can damage the natural skin barrier and increase the risk of life-threatening conditions. Colonization of pemphigus wounds with methicillin-resistant Staphylococcus aureus (MRSA) prolongs wound healing and increases mortality rate. Assessing MRSA prevalence, types, and toxin and adhesion genes can facilitate the detection of MRSA strains which cause infections, selection of appropriate treatments, and healing of pemphigus wounds. This study aimed to determine the SCCmec, the direct repeat unit (dru) types (dts), and the toxin, MSCRAMM, and biofilm genes of MRSA strains isolated from pemphigus wounds. METHODS: In this cross-sectional study, 118 S. aureus isolates were gathered from 118 patients with pemphigus. MRSA detection was performed using the mecA gene. Using the polymerase chain reaction method, all MRSA isolates were assessed for the presence of the sea, seb, sec, tst, eta, pvl, hla, hlb, MSCRAMM, and ica genes. Typing and subtyping were performed through respectively SCCmec typing and dru typing methods. The Bionumerics software was used for analyzing the data and drawing the minimum spanning tree. FINDINGS: From 118 S. aureus isolates, 51 were MRSA. SCCmec typing revealed the prevalence of SCCmec II with a prevalence of 64.7% (33 out of 51 isolates) and SCCmec III with a prevalence of 35.3% (18 out of 51 isolates). Dru typing indicated seven dts, namely dts 10a, 10g, 10m, 13i, 8h, 8i, and 9ca in two main clusters. The dt9ca was a new dru type and was registered in the dru-typing database (www.dru-typing.org). The prevalence rates of the hla, sea, and sec genes in MRSA isolates were respectively 54.9%, 27.4%, and 1.9%, while the hlb, seb, eta, and pvl genes were not detected at all. Only one MRSA with SCCmec III and dt10a carried the tst encoding gene. MSCRAMM gene analysis revealed the high prevalence of the eno (31.3%) and the fib (21.5%) genes. The prevalence rates of the icaA and icaD biofilm formation genes were 3.9% and 5.8%, respectively. There were no significant differences between the two detected SCCmec types and between the two detected dts clusters respecting the prevalence of the encoding genes of virulence factors and MSCRAMMs. CONCLUSION: The toxin genes hla and sea are prevalent among MRSA strains with SCCmec II and III isolated from pemphigus wounds. The most prevalent dts are dt10a and dt10g among MRSA with SCCmec III and dt8h and dt8i among MRSA with SCCmec II.

Comparative effects of granulocyte-colony stimulating factor and colistin-alone or in combination on burn wound healing in Acinetobacter baumannii infected mice.

BACKGROUND AND OBJECTIVES: Burn wounds are one of the most important health problems all over the world because infection after burn can delay wound healing. Treating burn wounds with granulocyte-colony stimulating factor (G-CSF) is known to improve healing of injured tissue. In addition, colistin is prescribed as an effective treatment. The aim of this study was to evaluate the effect of G-CSF and colistin alone or in combination with G-CSF on wound healing of Acinetobacter baumannii (A. baumannii) infected burns. MATERIALS AND METHODS: This study was performed between January 2016 and April 2018. Burn wounds were experimentally induced in 36 mice. The wounds were inoculated with A. baumannii. In a 7-day period, burn wounds in each group were daily treated with subcutaneous injections (0.1 ml) of saline, G-CSF, colistin, and G-CSF plus colistin. After killing the animals, the size of the wound, number of leukocytes in the skin and microbial growth were evaluated. A value of p ≤ 0.05 was considered statistically significant. RESULTS: Wound healing in the G-CSF plus colistin group was significantly higher than the control group and the G-CSF group (P = 0.023 and P = 0.033, respectively). In G-CSF+colistin group, the number of leukocytes was higher than the control group considerably (P = 0.007). On the 7th day of treatment, number of positive bacterial cultures in the colistin and the G-CSF plus colistin groups was lower than other groups with a significant difference. CONCLUSION: Concurrent consumption of G-CSF and antibiotics can control burn infection and enhance the immune system towards wound healing.