Molecular typing of selected Enterococcus faecalis isolates: pilot study using multilocus sequence typing and pulsed-field gel electrophoresis

The present study compared the recently developed multilocus sequence typing (MLST) approach with a well-established molecular typing technique, pulsed-field gel electrophoresis (PFGE), for subspecies differentiation of Enterococcus faecalis isolates. We sequenced intragenic regions of three E. faecalis antigen-encoding genes (ace, encoding a collagen and laminin adhesin; efaA, encoding an endocarditis antigen; and salA, encoding a cell wall associated antigen) and one housekeeping gene (pyrC) of 22 E. faecalis isolates chosen largely for their temporal and geographical diversity, but also including some outbreak isolates. MLST analysis of polymorphic regions of these four genes identified 13 distinct sequence types (STs) with different allelic profiles; the composite sequences generated from the four sequenced gene fragments of individual isolates showed 98.3 to 100% identity among the 22 isolates. We also found that the allelic profiles from two sequences, ace and salA, were sufficient to distinguish all 13 STs of this study. The 13 STs corresponded to 12 different PFGE types, with one previously designated PFGE clone (a widespread U.S. clone of beta-lactamase-producing isolates) being classified into two highly related STs which differed at 2 of 2,894 bases, both in the same allele. MLST also confirmed the clonal relationships among the isolates of two other PFGE clonal groups, including vancomycin resistant isolates. Thus, this pilot study with representative E. faecalis isolates suggests that, similar to PFGE, the sequence-based typing method may be useful for differentiating isolates of E. faecalis to the subspecies level in addition to identifying outbreak isolates.     

Presenting characteristics,comorbidities, and outcomes of patients coinfected with COVID-19 and Mycoplasma pneumoniae in the USA

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is spreading at a rapid pace, and the World Health Organization declared it as pandemic on 11 March 2020. Mycoplasma pneumoniae is an "atypical" bacterial pathogen commonly known to cause respiratory illness in humans. The coinfection from SARS-CoV-2 and mycoplasma pneumonia is rarely reported in the literature to the best of our knowledge. We present a study in which 6 of 350 patients confirmed with COVID-19 were also diagnosed with M. pneumoniae infection. In this study, we described the clinical characteristics of patients with coinfection. Common symptoms at the onset of illness included fever (six [100%] patients); five (83.3%) patients had a cough, shortness of breath, and fatigue. The other symptoms were myalgia (66.6%), gastrointestinal symptoms (33.3%-50%), and altered mental status (16.7%). The laboratory parameters include lymphopenia, elevated erythrocyte sedimentation rate, C-reactive protein, lactate dehydrogenase, interleukin-6, serum ferritin, and D-dimer in all six (100%) patients. The chest X-ray at presentation showed bilateral infiltrates in all the patients (100%). We also described electrocardiogram findings, complications, and treatment during hospitalization in detail. One patient died during the hospital course.     

CD4 cell counts in adults with newly diagnosed HIV infection in Barbados.

OBJECTIVE: To evaluate the absolute CD4 cell counts of all the newly diagnosed HIV-infected persons who presented at the Ladymeade Reference Unit (LRU), which serves as the national HIV/AIDS referral and treatment center for the country of Barbados. DESIGN AND METHODS: The study group was comprised of HIV-infected adults who had been diagnosed with HIV infection and referred to the LRU between January and December 2002. All the patients referred to the LRU had a CD4 cell count done at their first visit to the unit, as part of the routine workup to assess their disease status and need for antiretroviral therapy. RESULTS: Of the 106 newly diagnosed adults, 62 of them (58.5%) were males, who had a median age at presentation of 40 years; the other 44 of them (41.5%) were females, and their median age at presentation was 36 years. Nearly one-fifth (18.2%) of the females were aged 16-25 years, whereas only 8.1% of the males were in this age group. The majority (57.6%) of the study group were diagnosed because they presented with an HIV/AIDS-related illness. Overall, the median CD4 cell count at the time of diagnosis was 183/microL; 52 of 103 adults (50.5%) with a newly diagnosed HIV infection had a CD4 cell count that was < 200. Among males, the median CD4 cell count was 161/microL, and 32 (53.3%) of 60 males had CD4 cell counts < 200. In contrast, among females, the median CD4 cell count was 223, and 20 (46.5%) of 43 females had a CD4 cell count that was < 200/microL. However, this difference in the proportion of males and females with a CD4 cell count less than 200/microL was not statistically significant (P = 0.63). CONCLUSIONS: At the time of HIV diagnosis, over one-half of the adults had an initial CD4 cell count that was consistent with relatively advanced disease. Proportionally more women than men presented at a younger age, and proportionally more women than men presented in the early stages of the disease. These patterns indicate a clear need for enhanced educational efforts regarding the importance of HIV testing for at-risk individuals across Barbados. This testing could improve efforts to reduce transmission as well as the prognosis for patients who receive antiretroviral therapy.     

Acute and subacute oral toxicity of copper oxide nanoparticles in female albino Wistar rats

The extensive use of copper oxide nanoparticles (CuO‐NPs) in various industries and their wide range of applications have led to their accumulation in different ecological niches of the environment. This excess exposure raises the concern about its potential toxic effects on various organisms including humans. However, the hazardous potential of CuO‐NPs in the literature is elusive, and it is essential to study its toxicity in different biological models. Hence, we have conducted single acute dose (2000 mg/kg) and multiple dose subacute (30, 300 and 1000 mg/kg daily for 28 days) oral toxicity studies of CuO‐NPs in female albino Wistar rats following OECD guidelines 420 and 407 respectively. Blood analysis, tissue aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and acetylcholinesterase, superoxide dismutase, catalase, lipid malondialdehyde and reduced glutathione assays, and histopathology of the tissues were carried out. The higher dose treatments of the acute and subacute study caused significant alterations in biochemical and antioxidant parameters of the liver, kidney and brain tissues of the rat. In addition, histopathological evaluation of these three organs of treated rats showed significantly high abnormalities in their histoarchitecture when compared to control rats. We infer from the results that the toxicity observed in the liver, kidney and brain of treated rats could be due to the increased generation of reactive oxygen species by CuO‐NPs.