Journal of clinical microbiology
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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.
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J. Clin. Microbiol. · Oct 2017
Survival, Persistence, and Isolation of the Emerging Multidrug-Resistant Pathogenic Yeast Candida auris on a Plastic Health Care Surface.
The emerging multidrug-resistant pathogenic yeast Candida auris represents a serious threat to global health. Unlike most other Candida species, this organism appears to be commonly transmitted within health care facilities and causes health care-associated outbreaks. To better understand the epidemiology of this emerging pathogen, we investigated the ability of C. auris to persist on plastic surfaces common in health care settings compared with that of Candida parapsilosis, a species known to colonize the skin and plastics. ⋯ However, survival measured by esterase activity was higher for C. auris than C. parapsilosis throughout the 28-day study. Given the notable length of time Candida species survive and persist outside their host, we developed methods to more effectively culture C. auris from patients and their environment. Using our enrichment protocol, public health laboratories and researchers can now readily isolate C. auris from complex microbial communities (such as patient skin, nasopharynx, and stool) as well as environmental biofilms, in order to better understand and prevent C. auris colonization and transmission.
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J. Clin. Microbiol. · Aug 2017
Emergence of a Staphylococcus aureus Clone Resistant to Mupirocin and Fusidic Acid Carrying Exotoxin Genes and Causing Mainly Skin Infections.
Skin and soft tissue infections (SSTIs) caused by mupirocin-resistant Staphylococcus aureus strains have recently increased in number in our settings. We sought to evaluate the characteristics of these cases over a 43-month period. Data for all community-acquired staphylococcal infections caused by mupirocin-resistant strains were retrospectively reviewed. ⋯ Genotyping of methicillin-sensitive S. aureus (MSSA) strains revealed that 96/99 (96.7%) belonged to one main pulsotype, pulsotype 1, classified as sequence type 121 (ST121). The emergence of a single MSSA clone (ST121) causing impetigo was documented. Resistance to topical antimicrobials and a rich toxinogenic profile confer to this clone adaptability for spread in the community.
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J. Clin. Microbiol. · Jul 2017
Diagnostic Value of Galactomannan Antigen Test in Serum and Bronchoalveolar Lavage Fluid Samples from Patients with Nonneutropenic Invasive Pulmonary Aspergillosis.
The objective of this study was to compare the diagnostic value of galactomannan (GM) detection in bronchoalveolar lavage fluid (BALF) and serum samples from nonneutropenic patients with invasive pulmonary aspergillosis (IPA) and determine the optimal BALF GM cutoff value for pulmonary aspergillosis. GM detection in BALF and serum samples was performed by enzyme-linked immunosorbent assay (ELISA) in 128 patients with clinically suspected nonneutropenic pulmonary aspergillosis between June 2014 and June 2016. On the basis of the clinical and pathological diagnoses, 8 patients were excluded because their diagnosis was uncertain. ⋯ Receiver operating characteristic (ROC) curve analysis showed that when the BALF GM detection cutoff value was 0.7, its diagnostic value for pulmonary aspergillosis was optimized, and the sensitivity and specificity reached 72.97% and 89.16%, respectively. BALF GM detection was valuable for the diagnosis of IPA in nonneutropenic patients, and its diagnostic value was superior to that of serum GM detection. The optimal BALF GM cutoff value was 0.7.
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J. Clin. Microbiol. · Apr 2017
ReviewLaboratory Testing of Donors and Stool Samples for Fecal Microbiota Transplantation for Recurrent Clostridium difficile Infection.
Fecal microbiota transplantation is an efficacious and inexpensive therapy for recurrent Clostridium difficile infection, yet its safety is thought to depend on appropriate fecal donor screening. FDA guidance for regulation of this procedure is in flux, but screening and manufacture of fecal material from asymptomatic donors present many challenges to clinical laboratories. This minireview summarizes FDA regulatory changes, principles of donor selection, and recommended laboratory screening practices for fecal microbiota transplantation.