Effectiveness of preoperative decolonization with nasal povidone iodine in Chinese patients undergoing elective orthopedic surgery: a prospective cross-sectional study

Staphylococcus aureus colonization in the nares of patients undergoing elective orthopedic surgery increases the potential risk of surgical site infections. Methicillin-resistant S. aureus (MRSA) has gained recognition as a pathogen that is no longer only just a hospital-acquired pathogen. Patients positive for MRSA are associated with higher rates of morbidity and mortality following infection. MRSA is commonly found in the nares, and methicillin-sensitive S. aureus (MSSA) is even more prevalent. Recently, studies have determined that screening for this pathogen prior to surgery and diminishing staphylococcal infections at the surgical site will dramatically reduce surgical site infections. A nasal mupirocin treatment is shown to significantly reduce the colonization of the pathogen. However, this treatment is expensive and is currently not available in China. Thus, in this study, we first sought to determine the prevalence of MSSA/MSRA in patients undergoing elective orthopedic surgery in northern China, and then, we treated the positive patients with a nasal povidone-iodine swab. Here, we demonstrate a successful reduction in the colonization of S. aureus. We propose that this treatment could serve as a cost-effective means of eradicating this pathogen in patients undergoing elective orthopedic surgery, which might reduce the rate of surgical site infections.

The effects of ozone on bacterial growth and thiol-disulphide homeostasis in vascular graft infection caused by MRSA in rats

Abstract: Purpose: To investigate the microbiological, inflammatory and oxidant effects of adjuvant ozone administration in experimental rat vascular graft infection model which has not been previously investigated. Methods: Forty adult Wistar rats were divided into Sham, Control, Vancomycin, Ozone, Vancomycin+Ozone groups. Grafts were inoculated with Methicillin-resistant Staphylococcus aureus (MRSA) strain and implanted subcutaneously. Rats were treated intraperitoneally with ozone and /or intramuscularly with vancomycin for 10 days. Grafts were evaluated by quantitative bacterial cultures. Blood samples were harvested for determination of thiol-disulphide and cytokine profiles. Results: There was no significant difference in bacterial counts between Control and Ozone Groups. In the Ozone Group median colony count was significantly higher than the Vancomycin and Vancomycin+Ozone Groups. Total thiol and disulphide levels increased and disulphide/native thiol and disulphide/total thiol ratios decreased in Ozone Group significantly. Albumin levels decreased significantly in Vancomycin and Vancomycin+Ozone Groups compared to the Sham Group. IL-1 and TNF-alpha levels significantly increased in infected rats. Decreased levels of VEGF due to infection reversed by ozone therapy in control and vancomycin groups. Conclusions: We didn't observe any benefit of the agent on MRSA elimination in our model. Likewise, effects of ozone on thiol-disulphide homeostasis and inflammatory cytokines were contradictory.

Methicillin-resistant Staphylococcus aureus in HIV patients: Risk factors associated with colonization and/or infection and methods for characterization of isolates - a systematic review

Staphylococcus aureus is an important cause of infections and HIV-infected individuals are frequently susceptible to this pathogen. The aim of this study was to perform a systematic review to identify both the risk factors associated with colonization/infection by methicillin-resistant S. aureus in HIV patients and the methods used for characterization of isolates. An electronic search of articles published between January 2001 and December 2013 was first conducted. Among 116 studies categorized as being at a quality level of A, B or C, only 9 studies were considered to have high methodological quality (level A). The majority of these studies were retrospective (4/9 studies). The risk factors associated with colonization/infection by S. aureus were use of antimicrobials (4/9 studies), previous hospitalization (4/9 studies) and low CD4+ T lymphocyte counts (<200 cells/μl) (3/9 studies). Culture in mannitol salt agar (3/9 studies) and the latex agglutination test (5/9 studies) were the main methods used for bacterial phenotypic identification. Genotypic profiles were accessed by pulsed-field gel electrophoresis (6/9 studies) and USA300 was the most prevalent lineage (5/9 studies). Most isolates were resistant to erythromycin (3/9 studies) and susceptible to vancomycin (4/9 studies). Ultimately, use of antimicrobials and previous hospitalization were the main risk factors for colonization/infection by methicillin-resistant S. aureus in HIV-infected individuals. However, the numbers of evaluated patients, the exclusion and inclusion criteria and the characterization of the S. aureus isolates were not uniform, which made it difficult to establish the characteristics associated with HIV patients who are colonized/infected by S. aureus.

Low level laser therapy (AlGaInP) applied at 5J/cm2 reduces the proliferation of Staphylococcus aureus MRSA in infected wounds and intact skin of rats* / Laser de baixa intensidade (AlGaInP) aplicado com 5J/cm2 reduz a proliferação de Staphilococcus aureus MRSA em feridas infectadas e em pele íntegra de ratos

Laser therapy is a low cost, non-invasive procedure with good healing results. Doubts exist as to whether laser therapy action on microorganisms can justify research aimed at investigating its possible effects on bacteria-infected wounds. To assess the effect of low intensity laser on the rate of bacterial contamination in infected wounds in the skin of rats. An experimental study using 56 male Wistar rats. The animals were randomly divided into eight groups of seven each. Those in the "infected" groups were infected by Staphylococcus aureus MRSA in the dorsal region. Red laser diode (AlGaInP) 658nm, 5J/cm2 was used to treat the animals in the "treated" groups in scan for 3 consecutive days. Samples were drawn before inoculating bacteria and following laser treatment. For statistical analysis we used the nonparametric Wilcoxon (paired data) method with a significance level of p <0.05. The statistical analysis of median values showed that the groups submitted to laser treatment had low bacterial proliferation. The laser (AlGaInP), with a dose of 5J/cm2 in both intact skin and in wounds of rats infected with Staphylococcus aureus MRSA, is shown to reduce bacterial proliferation. .

Fundamentos: A terapia a laser é um procedimento de baixo custo, não invasiva e com bom desempenho na cicatrização. As dúvidas existentes quanto a sua ação sobre microrganismos justifica a realização de pesquisas visando investigar os possíveis efeitos em feridas infectadas por bactérias. Avaliar o efeito do laser de baixa intensidade sobre a taxa de contaminação bacteriana em feridas infectadas na pele de ratos. Estudo experimental, utilizando 56 ratos machos Wistar. Os animais foram distribuídos aleatoriamente em oito grupos de sete animais. Nos animais dos grupos lesionados foi realizada uma incisão na região dorsal.Os animais dos grupos infectados foram infectados por Staphylococcus aureus MRSA. os animais dos grupos tratados foram tratados com laser de Diodo vermelho (AlGaInP) 658nm, 5J/cm2 em varredura, durante 3 dias consecutivos. Foi colhida uma amostra antes de inocular as bactérias e outra após o tratamento com laser. Para a análise estatística foram utilizados os testes não paramétricos de Wilcoxon (dados pareados). Considerando como significante p<0,05. Através da análise estatística das medianas, observou-se que os grupos submetidos ao laser apresentavam uma proliferação bacteriana menor. O laser (AlGaInP), com uma dose de 5J/cm2, tanto em feridas quanto em pele íntegra de ratos infectados por Staphilococcus aureus MRSA, se mostrou capaz de reduzir a proliferação bacteriana. .