RESUMO
Infections caused by extended-spectrum ß-lactamases (ESBLs) producing bacteria, including Klebsiella pneumoniae have increasingly subjected to therapeutic limitations and patients with these infections are at high risk for treatment failure, long hospital stays, high health care costs, and high mortality. The aim of this study was to screen the prevalence of the bla TEM,bla CTX-M and bla SHV ESBL genes in K. pneumoniae strains isolated from nosocomial urinary tract infections (UTIs). During the March 2016 to December 2017, one hundred isolates of K. pneumoniae were collected from urine specimens of patients suffering from nosocomial UTI referred to Khatam Al-Anbia hospital in Shahrud, north-central Iran. All isolates were identified by standard bacteriological tests. The pattern of antibiotic susceptibility was determined according to the CLSI guidelines. The presence of the ESBLs was investigated using the double-disc synergy test (DDST). Polymerase chain reaction technique was used to detect the bla TEM, bla CTX-M and bla SHV genes in DDST positive isolates. Most isolates showed remarkable resistance to tested antibiotics with highest rate against nitrofurantoin (75%) and trimethoprim/sulfamethoxazole (65%). The imipenem was the most effective antibiotic against K. pneumoniae isolates. ESBL phenotype was detected in 50 (50%) of isolates. The prevalence of bla TEM, bla CTX-M and bla SHV genes among 50 ESBLs-positive isolates was 25 (50%), 15 (30%) and 35 (70%) respectively. The bla TEM and bla SHV genes were seen in 25 isolates (50%) simultaneously. The findings of this study indicated the 50% frequency rate of ESBL-producing K. pneumoniae in our geographic region. Since the treatment of infections caused by this bacterium is associated with many limitations, this high prevalence is a warning sign to adopt new control policies to prevent further spread of this microorganism.
RESUMO
Purpose: Dental unit's environment and relevant instruments are a major source of infectious diseases caused by a variety of microorganisms. The application of various disinfectants is one of the most effective methods for reducing or eliminating microbial contamination. The objective of this study was to evaluate the antibacterial effects of deconex and sodium hypochlorite against bacterial taxa isolated from dental unit's environment of Ahvaz Jundishapur University of Medical Sciences, southwest of Iran. Methods: In order to evaluate the quality of disinfection, sampling was performed from different parts of 100 clinical units. For bacterial recovery and isolation, samples were enriched and cultured onto different microbiological culture media. Species identification was carried out using phenotypic and molecular methods (16S rDNA sequence analysis). In vitro activity of sodium hypochlorite and deconex were determined by the broth micro-dilution method. Results: According to conventional techniques, Bacillus spp (48%) was the most frequently encountered isolates, followed by staphylococcus spp (26%). By using both techniques, Bacillus subtilis was the most frequently encountered species (n=23, 21%), followed by Bacillus licheniformis (n=8, 7.4%), Streptococcus pneumonia (n=8, 7.4%), Staphylococcus epidermidis (n=8, 7.4%), Staphylococcus saprophyticus (n=8, 7.4%) and Staphylococcus warneri. The highest levels of contamination were observed in oral medications. The deconex had lower minimum inhibitory concentration (MIC) concentration in comparasion to sodium hypochlorite, which showed that deconex was a much more potent disinfectant. Conclusion: In conclusion, the results of the present in vitro study showed that deconex had promising results for decontamination of the tested microorganism, and it is recommended for disinfecting of dental units and environment. In this study, the high percentage of dental unit's contamination showed the need to improve disinfection procedures, sterilization systems, and the use of an appropriate concentration of deconex and sodium hypochlorite for dental units decontamination .
