Pneumocystis jirovecii Pneumonia in Patients with Nephrotic Syndrome: Application of Lymphocyte Subset Analysis in Predicting Clinical OutcomesRead the full article
Canadian Journal of Infectious Diseases and Medical Microbiology publishes original research articles, review articles, and clinical studies related to infectious diseases of bacterial, viral and parasitic origin.
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Gut Microbiota Alterations from Three-Strain Yogurt Formulation Treatments in Slow-Transit Constipation
The objective of this study was to evaluate the effects of a three-strain yogurt formulation in slow-transit constipation (STC) patients. Each individual in both treatment groups consumed 250 mL of the formulated yogurt daily for a week (7 days), and fecal samples were collected for gut microbiota and short-chain fatty acid (SCFA) analyses. A significant increase in the defection frequency () and bacterial diversity () at the 100% sequence homology level and a decrease in the concentrations of acetic acid (), propionic acid (), and butanoic acid () were observed after the STC patients consumed three-strain yogurt formulation. In addition, the consumption of the three-strain yogurt formulation significantly altered the composition of the intestinal bacteria in the STC patients. The relative abundances of 23 genera in the top dominating genera were altered significantly after the STC patients consumed the yogurt. In summary, the consumption of 250 mL day− the three-strain yogurt formulation described in this study can play a role in improving the symptoms of STC.
Carriage of Extended-Spectrum-β-Lactamase- and AmpC-β-Lactamase-Producing Enterobacteriaceae (ESBL-PE) in Healthy Community and Outpatient Department (OPD) Patients in Nepal
Background. Extended-spectrum β-lactamase (ESBL)- and AmpC-β-lactamase-producing Enterobacteriaceae have recently emerged as a public threat in the treatment of nosocomial as well as community-acquired infections. Very little information is currently available about its existence in Nepal. We, therefore, aim to determine the prevalence of ESBL and AmpC-β-lactamase-producing Enterobacteriaceae and also to determine their drug resistance pattern. Methods. During a 6-month period (November 2014–April 2015), a total of 190 stool specimens from 190 participants were obtained from different population. Of the total 260 fecal isolates, 152 from outpatient department (OPD) and 108 from healthy volunteer were collected. Stool specimens were cultured and enterobacterial isolates were subjected to antimicrobial susceptibility tests according to the standard microbiologic guidelines. ESBL was screened using ceftazidime (CAZ, 30 μg) and cefotaxime (CTX, 30 μg) disks and confirmed by double-disk synergy test. AmpC-β-lactamase enzyme production was detected by the aminophenylboronic acid inhibitor-based detection method. Antibiotic susceptibility test was performed for ESBL-positive isolates as per the Kirby-Bauer disk diffusion method, and interpretation was done according to CLSI (Clinical and Laboratory Standard Institute). Results. The prevalence of ESBL, AmpC-β-lactamases, and coproducer (ESBL + AmpC-β-lactamase) producing Enterobacteriaceae in OPD participants were 30.92%, 18.4%, and 13.81%, respectively, while 25%, 6.4%, and 1.8% in healthy population. ESBL-producing E. coli was 70.2% followed by K. pneumoniae (12.7%), and among AmpC-β-lactamase producer, E. coli were detected in half of the isolates (14/28, 50.0%) among OPD patients. Similarly, E. coli remained the most frequent ESBL producers 21/27 (77.8%) followed by K. pneumoniae 4/27 (14.21%) in healthy participants, and K. pneumoniae 5/7 (71.42%) and C. freundii 2/7 (28.57%) were detected highest among AmpC-β-lactamase-producing isolates. All isolates were highly sensitive (100%) to imipenem in both OPD and healthy participants. Conclusion. Our study revealed a high prevalence of ESBL- and AmpC-β-lactamase-producing enteric pathogen in Nepalese OPD and healthy population. The significant increase of these isolates and increased rate of drug resistance indicates a serious threat that stress the need to implement the surveillance system and a proper control measure so as to limit the spread of ESBL-producing Enterobacteriaceae (ESBL-PE) in both OPD as well as in community. Therefore, healthcare providers need to be aware that ESBL- and AmpC-β-lactamase-producing strains are not only circulating in hospital environments but also in the community and should be dealt with accordingly.
Measles Virus Imported by International Traveler in Jiangsu Province of China, in 2018 and 2019
Measles remains a public health concern in many regions, and the imported measles cases continue to challenge the measles elimination program for most of the countries where measles was verified to be eliminated or approaching elimination. The imported measles cases have been reported since October, 2017, in Jiangsu province, China. In this study, we reported the first imported B3 genotype measles virus from Egypt and the second imported D8 genotype measles virus from Philippines through international traveling. No secondary measles cases were found after these imported cases. Our findings highlighted the importance of measles vaccination targeting international travelers in China.
Frequent Recurrences of Genital Herpes Are Associated with Enhanced Systemic HSV-Specific T Cell Response
Objectives. Genital herpes simplex virus (HSV) infection is controlled by HSV-specific T cells in the genital tract, and the role of systemic T cell responses is not fully understood. Thus, we analysed T cell responses in patients with recurrent genital herpes (GH). Methods. T cell responses to HSV-1 and HSV-2 native antigens and the expression of HLA-DR and CD38 molecules on circulating CD8+ T cells were analysed in adults with high frequency of GH recurrences (19 patients) and low frequency of GH recurrences (7 patients) and 12 HSV-2 seronegative healthy controls. The study utilized the interferon-γ Elispot assay for measurement of spot-forming cells (SFC) after ex vivo stimulation with HSV antigens and flow cytometry for analysis of the expression of activation markers in unstimulated T cells. Results. The patients with high frequency of GH recurrences (mean number of recurrences of 13.3 per year) had significantly enhanced HSV-specific T cell responses than the HSV-2 seronegative healthy controls. Moreover, a trend of higher numbers of SFC was observed in these patients when compared with those with low frequency of GH recurrences (mean number of recurrences of 3.3 per year). Additionally, no differences in CD38 and HLA-DR expression on circulating CD8+ T cells were found among the study groups. Conclusions. Frequency of GH recurrences positively correlates with high numbers of systemic HSV-specific T cells.
Single Nucleotide Polymorphisms in IFN-γ Signaling Pathway Associated with Risk of Hepatitis B Virus Infection in Chinese Children
Hepatitis B virus (HBV) infection is a challenging public health problem in China and worldwide. Mother-to-child transmission is one of the main transmission routes of HBV in highly endemic regions. However, the mechanisms of HBV perinatal transmission in children have not been clearly defined. The aim of this study was to demonstrate the association between single-nucleotide polymorphisms (SNPs) in IFN-γ signaling pathway and HBV infection or breakthrough infection in children. Two hundred and seventy-four HBV-infected children defined as test positive for hepatitis B surface antigen (HBsAg) and 353 controls defined as negative for HBsAg in China were recruited from October 2013 to May 2015. SNPs in IFN-γ signaling pathway including IFNG, IFNGR1, IFNGR2, and IL12B were genotyped. Rs2234711 in IFNGR1 was significantly associated with HBV infection in children (OR = 0.641, 95% CI: 0.450–0.913). In addition, rs2234711 was also significantly associated with HBV breakthrough infection in children born to HBsAg-positive mothers (OR = 0.452, 95% CI: 0.205–0.998). Our study confirmed that genetic variants in IFN-γ signaling pathway have significant associations with HBV infection, especially with HBV breakthrough in children. This study provides insight into HBV infection in children and could be used to help design effective strategies for reducing immunoprophylaxis failure.
Comparative Study of Clostridium difficile Clinical Detection Methods in Patients with Diarrhoea
Objectives. The aim of this study was to evaluate the clinical application of three methods for detecting Clostridium difficile in fecal samples. Methods. One hundred and fifty fecal specimens were collected and tested for C. difficile using three methods: (1) the toxigenic culture (TC); (2) the VIDAS enzyme immunoassay (EIA): the VIDAS glutamate dehydrogenase (GDH) assay and toxin A/B assay were used to detect GDH antigen and A/B toxin; and (3) the GeneXpert PCR assay. The toxigenic culture was used as a reference to evaluate the performance of the VIDAS EIA and the GeneXpert PCR assay. Results. Of 150 specimens, 26 carried both A and B toxin genes, and none of the samples were positive for the binary toxin gene. Toxin-producing C. difficile was found in 17.3% (26/150) of the samples. Thirty-seven GDH-positive samples were detected using the VIDAS GDH assay, and 15 toxin-positive samples were detected using the VIDAS toxin A/B assay. The GeneXpert PCR assay was used to detect C. difficile in 79 specimens simultaneously, and a total of 18 positive specimens were detected. Conclusion. The VIDAS GDH assay is useful for initial screening of C. difficile. The GeneXpert PCR assay is a simple and quick method.