Rapid PCR/ESI-MS-based molecular genotyping of Staphylococcus aureus from nasal swabs of emergency department patients

Emergency Department Environmental Contamination With Methicillin-Resistant Staphylococcus aureus After Care of Colonized Patients

STUDY OBJECTIVE

Methicillin-resistant Staphylococcus aureus (MRSA) transmission dynamics in the emergency department (ED) are not well defined; environmental surfaces may serve as reservoirs for transmission. This study investigates the effect of patients with a history of MRSA colonization or infection on subsequent MRSA contamination of the ED environment.

METHODS

Adult ED patients with evidence of an MRSA-positive surveillance result or clinical microbiologic culture in the year preceding their current ED visit were enrolled. Cultures from 5 anatomic sites were obtained to detect active MRSA colonization. After patients' discharge and before environmental disinfection, up to 16 prespecified surfaces in their ED rooms were cultured. Strain typing was performed by repetitive-sequence polymerase chain reaction on all recovered MRSA isolates to determine concordance with the corresponding patient strain.

RESULTS

Of 42 patients enrolled, 25 (60%) remained colonized with MRSA. Nineteen of the 25 ED rooms (76%) occupied by MRSA-colonized patients contained greater than or equal to 1 MRSA-contaminated environmental surface on patient discharge. Surfaces were more likely to be contaminated when rooms were occupied by patients colonized with MRSA at 1 body site (odds ratio 11.7; 95% confidence interval 1.5 to 91.5) and greater than or equal to 2 body sites (odds ratio 16.3; 95% confidence interval 3.1 to 86.8) compared with noncolonized patients. In 16 of the 19 ED rooms (84%) where MRSA was recovered, all environmental strains were concordant with the corresponding patient strain.

CONCLUSION

Contamination of the ED environment with MRSA from actively colonized patients is common. Improved environmental surface disinfection may help reduce transmission of MRSA to ED health care professionals and patients during emergency care.

Prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus among nasal carriage strains isolated from emergency department patients and healthcare workers in central Taiwan

BACKGROUND AND OBJECTIVE

Screening and identification of methicillin-resistant Staphylococcus aureus (MRSA) carriage are helpful for controlling MRSA dissemination in hospitals. The aim of our study was to determine the prevalence of nasal carriages and diversity of MRSA among patients and healthcare workers (HCWs) at two regional hospitals in Taiwan.

METHODS

Nasal swabs were obtained prospectively from 204 patients visiting the emergency department (ED) and 326 HCWs in two regional hospitals in Changhua, Taiwan, between February 2015 and June 2015. All the MRSA isolates were further molecularly characterized.

RESULTS

Of the 204 participating patients, the nasal carriage rates of S. aureus and MRSA were 22.1% and 7.8%, respectively. For HCWs, the S. aureus and MRSA carriage rates were 26.1% and 6.1%, respectively. There was no statistically significant difference in MRSA carriage rate between patients and HCWs (P = 0.447). Patients receiving hemodialysis were significantly associated with MRSA colonization (P = 0.012). The leading three sequence types (ST) were ST59 (16, 44.4%), ST45 (11, 30.6%), and ST239 (3, 8.3%) for all 36 MRSA isolates. ST59/SCCmec IV/t437/PVL-negative and ST45/SCCmec V/t1081/PVL-negative were the predominant clones among HCWs (30%) and participating patients (19%), respectively.

CONCLUSION

Overall, a substantial proportion of patients visiting the ED and HCWs harbored CA-MRSA, mostly ST59 strains, in their nares. It is noteworthy that MRSA ST45 strains supplanted ST239 as the second leading nasal MRSA colonization strain in our study.

Ventriculostomy-related infections in subarachnoid hemorrhage patients-a retrospective study of incidence, etiology, and antimicrobial therapy

BACKGROUND

This study was performed to investigate the incidence and etiology of ventriculostomy-related infections (VRIs) in patients with subarachnoid hemorrhage (SAH) and to assess adherence to local clinical guidelines regarding empirical antimicrobial therapy and diagnostic routines.

METHODS

A total of 191 consecutive SAH patients treated in the neuro-intensive care unit of Uppsala University Hospital between 2010 and 2013 were included retrospectively. Information regarding cerebrospinal fluid samples, bacterial cultures, ventriculostomy treatment, patient characteristics, and antibiotic treatment were collected from electronic patient records.

RESULTS

Eleven patients developed VRI, resulting in an incidence of 5.8% per patient, 5.4% per ventriculostomy catheter, and 4.1 per 1000 catheter days. Coagulase-negative staphylococci caused nine cases of VRI and Klebsiella pneumoniae and Staphylococcus aureus caused one each. Empirical VRI therapy was initiated on 97 occasions in 81 subjects (42.4%). Out of the 11 patients with VRI, four did not receive empirical antibiotic therapy before the positive culture result. The clinical actions performed after analysis of CSF samples were in line with the action suggested by the local guidelines in 307 out of 592 cases (51.9%).

CONCLUSIONS

The incidence of VRI in our cohort was comparable to what has previously been reported. Coagulase-negative staphylococci was the most common agent. Our study demonstrates the difficulty in diagnosing VRI in SAH patients. Improved adherence to clinical guidelines could to some extent reduce the use of empirical antibiotic treatment, but better diagnostic methods and routines are needed.

Evaluation of the frequency of the IL-28 polymorphism (rs8099917) in patients with chronic hepatitis C using Zip nucleic acid probes, Kerman, Southeast of Iran

Polymorphisms in the region of the interleukin IL-28 gene on chromosome 19 have been related with clearance of hepatitis C virus (HCV), a major human pathogen responsible for chronic hepatitis, cirrhosis and hepatocellular carcinoma. About 3% of the world's population is infected with HCV. The long-term response to therapy is influenced by many host and viral factors, and recent evidence has indicated that some host genetic polymorphisms related to IL-28 are the most powerful predictors of virological response in patients with HCV. This study assessed frequency of the IL-28 polymorphism (rs8099917) in 50 patients (39 men and 11 women ) with chronic hepatitis C using ZNA probe real time PCR new method . All patients were tested for genotype of HCV and the HCV viral load. In parallel, the levels of SGOT, SGPT and ALK enzymes were assessed. Treatment using Peg-interferon alpha with ribavirin was conducted for patients and subsequently samples were collected to detect any change in viral load or liver enzyme rates. The overall frequency of the TT allele is 74%, TG allele 20% and GG allele 6% and the percent of patients who had T allele was 84%. Clear reduction in viral load and liver enzymes was reported in patients with the T allele. Especially for genotype 1 which is relatively resistant to treatment, these alleles may have a role in this decline. In conclusion, we showed that IL-28 polymorphism rs8099917 strongly predicts virological response in HCV infection and that real-time PCR with Zip nucleic acid probes is a sensitive, specific and rapid detection method for detection of SNPs which will be essential for monitoring patients undergoing antiviral therapy.