Journal of clinical microbiology
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J. Clin. Microbiol. · Mar 2018
Comparative StudyComparison of Four Serological Methods and Two Reverse Transcription-PCR Assays for Diagnosis and Surveillance of Zika Virus Infection.
Zika virus (ZIKV) is a mosquito-borne flavivirus that is responsible for recent explosive epidemics in the Americas. Notably, ZIKV infection during pregnancy has been found to cause congenital birth defects, including microcephaly, and ZIKV has been associated with Guillain-Barré syndrome in adults. Diagnosis and surveillance of Zika in the Americas have been challenging due to similar clinical manifestations and extensive antibody cross-reactivity with endemic flaviviral diseases, such as dengue. ⋯ An inhibition ELISA detecting total anti-ZIKV antibodies had sensitivity and specificity values of 68.3% and 58.3% for diagnosis and 94.0% and 98.6% for measuring annual infection incidence. Finally, the ZCD and Trioplex real-time RT-PCR assays detecting Zika, chikungunya, and dengue viruses both yielded a sensitivity of 96.1% and specificity of 100%. Together, these assays resolve the urgent need for diagnostic and surveillance tools for countries affected by Zika virus infections.
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Candida auris has emerged globally as a multidrug-resistant health care-associated fungal pathogen. Recent reports highlight ongoing challenges due to organism misidentification, high rates of antifungal drug resistance, and significant patient mortality. The predilection for transmission within and between health care facilities possibly promoted by virulence factors that facilitate skin colonization and environmental persistence is unique among Candida species. This minireview details the global emergence of C. auris and discusses issues relevant to clinical microbiology laboratories, hospital infection control, and antimicrobial stewardship efforts.
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J. Clin. Microbiol. · Feb 2018
Perioperative Antibiotic Prophylaxis Has No Effect on Time to Positivity and Proportion of Positive Samples: a Cohort Study of 64 Cutibacterium acnes Bone and Joint Infections.
If a bone or joint infection is suspected, perioperative antibiotic prophylaxis is frequently withheld until intraoperative microbiological sampling has been performed. This practice builds upon the hypothesis that perioperative antibiotics could render culture results negative and thus impede tailored antibiotic treatment of infections. We aimed to assess the influence of antibiotic prophylaxis within 30 to 60 min before surgery on time to positivity of microbiological samples and on proportion of positive samples in Cutibacterium acnes bone and joint infections. ⋯ Within the infection group, we found no difference in time to positivity between those who had or had not received a perioperative prophylaxis (7.07 days; 95% confidence interval [CI], 6.4 to 7.7, versus 7.11 days; 95% CI, 6.8 to 7.5; P = 0.3). Also, there was no association between the proportion of sample positivity and the application of perioperative prophylaxis (71.6% versus 65.9%; P = 0.39). Since perioperative prophylaxis did not negatively influence the microbiological yield in C. acnes infections, antibiotic prophylaxis can be routinely given to avoid surgical site infections.
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J. Clin. Microbiol. · Jan 2018
Multicenter StudyMulticenter Evaluation of the Xpert MRSA NxG Assay for Detection of Methicillin-Resistant Staphylococcus aureus in Nasal Swabs.
Health care-associated methicillin-resistant Staphylococcus aureus (MRSA) infections are a burden on the health care system. Clinical laboratories play a key role in reducing this burden, as the timely identification of MRSA colonization or infection facilitates infection control practices that are effective at limiting invasive MRSA infections. The Xpert MRSA NxG assay recently received FDA clearance for the direct detection of MRSA from nasal swabs. ⋯ The positive predictive value (PPV) for rayon swabs was 78.7%, versus 83.5% for ESwabs. The negative predictive values (NPVs) for rayon swabs and ESwab specimens were 98.9% and 99.1%, respectively. In conclusion, the Xpert MRSA NxG assay is a sensitive and specific assay for the direct detection of MRSA from nasal swab specimens.
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J. Clin. Microbiol. · Oct 2017
Serum Hepatitis B Virus DNA, RNA, and HBsAg: Which Correlated Better with Intrahepatic Covalently Closed Circular DNA before and after Nucleos(t)ide Analogue Treatment?
The study was designed to investigate whether serum hepatitis B virus (HBV) RNA is a strong surrogate marker for intrahepatic HBV covalently closed circular DNA (cccDNA) compared with serum HBV DNA, hepatitis B surface antigen (HBsAg), and hepatitis B e antigen (HBeAg) in HBeAg-positive chronic hepatitis B (CHB) patients. Serum HBV RNA, HBV DNA, HBsAg, HBeAg, and intrahepatic cccDNA were quantitatively detected at baseline (n = 82) and 96 weeks (n = 62) after treatment with nucleos(t)ide analogue (NUC) in HBeAg-positive CHB patients. The correlations among serum HBV RNA, HBV DNA, HBsAg, HBeAg, and intrahepatic cccDNA levels were then statistically analyzed. ⋯ At 96 weeks after NUC treatment, intrahepatic cccDNA levels correlated well with HBsAg levels (r = 0.39, P < 0.01) but not with serum HBV RNA, HBV DNA, and HBeAg levels (all P > 0.05). Besides, the decline in the intrahepatic cccDNA level from baseline to week 96 correlated better with the reduction in the serum HBsAg levels than with the decreases in the levels of the other markers (for the HBsAg decline, r = 0.38, P < 0.01; for the HBV DNA decline, r = 0.35, P = 0.01; for the HBV RNA decline, r = 0.28, P < 0.05; for the HBeAg decline, r = 0.18, P = 0.19). In conclusion, the baseline serum HBV RNA level or its decline after 96 weeks of NUC therapy correlated with the corresponding intrahepatic cccDNA level, while it was less than that seen with serum HBV DNA at baseline and HBsAg (or its decline) at 96 weeks after treatment, respectively.