Canadian Journal of Infectious Diseases and Medical Microbiology

The researchers are paying more attention to the role of gut commensal bacteria in health development beyond the classical pathogens. It has been widely demonstrated that dysbiosis, which means the alternations of the gut microbial structure, is closely associated with development of intestinal chronic inflammation-related diseases such as inflammatory bowel disease (IBD), and even infectious diseases including bacterial and viral infection. Thus, for reshaping ecological balance, a growing body of the literatures have proposed numerous strategies to modulate the structure of the gut microbiota, which provide more revelation for amelioration of these inflammation or infection-related diseases. While the ameliorative effects of traditional probiotics seem negligeable, emerging next generation probiotics (NGPs) start to receive great attention as new preventive and therapeutic tools. Encouragingly, within the last decade, the intestinal symbiotic bacterium Faecalibacterium prausnitzii has emerged as the “sentinel of the gut,” with multifunction of anti-inflammation, gut barrier enhancement, and butyrate production. A lower abundance of F. prausnitzii has been shown in IBD, Clostridium difficile infection (CDI), and virus infection such as COVID-19. It is reported that intervention with higher richness of F. prausnitzii through dietary modulation, fecal microbiota transplantation, or culture strategy can protect the mice or the subjects from inflammatory diseases. Therefore, F. prausnitzii may have potential ability to reduce microbial translocation and inflammation, preventing occurrences of gastrointestinal comorbidities especially in COVID-19 patients.

Objectives. To investigate the effects of cytotoxin-associated gene A- (CagA-) positive Helicobacter pylori on proliferation, invasion, autophagy, and expression of miR-125b-5p in colon cancer cells. Methods. Colon cancer cells were cocultured with H. pylori (CagA+) to analyze the effects of H. pylori on miR-125b-5p and autophagy. Colon cancer cells infected with H. pylori (CagA+) were mimicked by transfection of CagA plasmid. The effects of CagA on the proliferation, invasion, and autophagy of colon cancer cells were analyzed. Cell counting kit-8 (CCK-8), clone formation, and Transwell assays were used to detect cell viability, proliferation, and invasion ability, respectively. Proteins and miRNAs were detected by western blotting and qPCR, respectively. Results. H. pylori (CagA+) inhibited expression of miR-125b-5p and promoted autophagy in colon cancer cells. MiR-125 b-5p was underexpressed in colon cancer cells after CagA overexpression. CagA promoted colon cancer cell proliferation, invasion, and autophagy. Overexpression of miR-125b-5p inhibited the proliferation, invasion, and autophagy of colon cancer cells and reversed the effects of CagA. Conclusion. H. pylori (CagA+) infection may promote the development and invasion of colon cancer by inhibiting miR-125b-5p.

Background. Healthcare workers (HCWs) may be using their mobile phones (MPs) to carry microbes that cause hospital-acquired and community infections in general. With antibiotic resistance problem emergence, these infections can be challenging to eradicate. Hence, this study aimed to determine the microbial contamination of HCW MPs and identify and classify bacterial isolates in Palestine. Methods. This was a 7-month comparative cross-sectional analysis of 200 HCW MPs from 2 hospitals and 100 MPs from university students (non-HCWs). Data collection was done using a self-administrated questionnaire, and a swab sample from both HCW and non-HCW MPs was obtained and transferred to An-Najah National University (NNU) microbiology lab for bacterial identification and antibiotic susceptibility. Data were analyzed using Social Sciences Statistical Package (SPSS) version 22.0. Result. Among HCWs, the microbial contamination was 87.5%. Coagulase-negative staphylococci (CoNS; 67.3%), methicillin-sensitive Staphylococcus aureus (MSSA; 17.5%), Gram-positive bacilli (4.1%), methicillin-resistant Staphylococcus aureus (MRSA; 1.6%), and Gram-negative species (1.6%) were the most predominant bacterial isolates. More than half of staphylococci isolates were resistant to penicillin and erythromycin. Male gender, using a mobile phone in the bathroom, and entry to the operating theatre were associated with mobile phone contamination and increased resistance against specific antibiotics. Among non-HCWs, the contamination was 86%. The most predominant bacterial isolates were CoNS, MSSA, and Gram-positive bacilli, with a contamination of 66.8%, 28.5%, and 2.6%, respectively. No MRSA or Gram-negative species were detected in this group. Antibiotic resistance percentage of staphylococci was nearly half of that yielded in the HCW group against each antibiotic. Conclusion. Significant numbers of bacteria have been isolated from HCW MPs. Working in a hospital environment frequently raises the probability of presence of antibiotic-resistant bacteria on a MP. Therefore, infection control teams should discuss methods to prevent the transmission of drug-resistant pathogens from HCW MPs.

Background. Coronavirus disease-19 (COVID-19) is a new type of coronavirus that has caused a global pandemic. The disease is highly contagious, and all people are susceptible to the disease. Therefore, extensive measures were taken to prevent the spread of the disease at the community and hospitals. This study aimed to investigate the impact of COVID-19 outbreak on nosocomial infection rate. Methods. This cross-sectional study was conducted in an educational hospital, southeast Iran. The nosocomial infection rates of critical/intensive care units (CCU/ICUs) and medical-surgical units were assessed during and before the COVID-19 outbreak. Results. There was a 19.75-point decrease in the total rate of nosocomial infection during the COVID-19 outbreak ( = 0.02). In addition, there was a 39.12-point decrease in the total rate of CCU/ICUs’ nosocomial infection during the COVID-19 outbreak ( < 0.001). A 19.23-point decrease was also observed in the total rate of medical-surgical units’ nosocomial infection during the COVID-19 outbreak ( = 0.13). All kinds of CCU/ICUs’ nosocomial infections had between 31.22- and 100-point decreases during the COVID-19 outbreak. Among medical-surgical units, 33.33- and 30.70-point decreases were observed only in UTI and SSI, respectively, during the COVID-19 outbreak, while BSI had a 40-point increase during the COVID-19 outbreak. Conclusions. Proper implementation of infection control protocols during the COVID-19 pandemic seems to reduce nosocomial infections.

Background. Nontuberculous mycobacteria (NTM) are widely present in environments, such as soil and water, and have recently been recognized as important pathogenic bacteria. The incidence of NTM-related infections is steadily increasing. As the diagnosis and treatment of NTM infection should be distinguished from tuberculosis, and the treatment should be specific to the species of NTM acquired, accurate species identification is required. Methods. In this study, two-step multiplex PCR (mPCR) and multigene sequence-based analysis were used to accurately identify NTM species in 320 clinical isolates from Gyeongsang National University Hospital (GNUH). In particular, major mycobacterial strains with a high isolation frequency as well as coinfections with multiple species were diagnosed through two-step mPCR. Multigene sequencing was performed to accurately identify other NTM species not detected by mPCR. Variable regions of the genes 16S rRNA, rpoB, hsp65, and 16S-23S rRNA internal transcribed spacer were included in the analysis. Results. Two-step mPCR identified 234 (73.1%) cases of M. intracellulare, 26 (8.1%) cases of M. avium subsp. avium, and 13 (4.1%) cases of M. avium subsp. hominissuis infection. Additionally, 9 (2.8%) M. fortuitum, 9 (2.8%) M. massiliense, 2 (0.6%) M. abscessus, and 4 (1.2%) M. kansasii isolates were identified. Coinfection was identified in 7 (2.2%) samples. The sixteen samples not classified by two-step mPCR included 6 (1.9%) cases of M. chimaera, 4 (1.3%) M. gordonae, 1 (0.3%) M. colombiense, 1 (0.3%) M. mageritense, and 1 (0.3%) M. persicum identified by sequence analysis. Conclusions. The results of this study suggest a strategy for rapid detection and accurate identification of species using two-step mPCR and multigene sequence-based analysis. To the best of our knowledge, this study is the first to report the identification of NTM species isolated from patients in Gyeongnam/Korea.

Objective. Candida glabrata (C. glabrata) causes infections associated with severe sepsis and high mortality. This study describes the effects of micafungin (MCF), itraconazole (ICZ), and amphotericin B (AmB) on the function of macrophages during C. glabrata infection. Methods. RAW264.1 macrophages were treated with MCF, ICZ, or AmB and then challenged with C. glabrata. Cytokines from infected macrophage supernatants and the levels of superoxide dismutase (SOD) in macrophages were measured at different time points after phagocytosis. Results. The activity of SOD was significantly increased in RAW264.1 cells that phagocytized C. glabrata and reached a peak level at 6 hours (). ICZ and AmB did not affect the SOD activity in cells that phagocytized C. glabrata versus that in untreated macrophage. C. glabrata stimulated macrophages to secrete cytokines. Neither ICZ nor AmB affected the secretion of interleukin-6 (IL-6), interleukin-8 (IL-8), or tumor necrosis factor-α (TNF-α) by C. glabrata-infected macrophages. However, MCF downregulated the secretion of TNF-α by infected macrophages and reduced the SOD activity of C. glabrata compared with those in untreated controls. Conclusion. Echinocandins may increase their antifungal efficacy by altering the innate immune response of macrophages and attenuating antioxidants of this organism.