Canadian Journal of Infectious Diseases & Medical Microbiology最新文献

Coxiellaburnetii is an airborne bacterial zoonotic pathogen that causes Q fever/coxiellosis in humans and animals. Although dogs are suspected of transmitting Q fever to humans in past outbreaks, the prevalence of C. burnetii in the Indian dog population and risk factors for infection remain unknown. In this study, 452 dogs from pet clinics in three Indian states were screened for coxiellosis using molecular (Trans-PCR, Com 1-PCR) and serological (IFAT) tests. C. burnetii DNA was detected in 0.44% of blood samples using Trans-PCR, and pathogen-specific antibodies were found in 4.20% of sera using IFAT. Contact with stray dogs and ownership by farmers were identified as risk factors for canine coxiellosis. This study appears to be the first systematic assessment of coxiellosis and associated risk factors among dogs in India. A large-scale assessment of canine coxiellosis and its risk factors is warranted among pets and high-risk occupational groups in India.

In December 2022, China classified COVID-19 as a category B infectious disease. This ended 2 years of close epidemiological surveillance of COVID-19. The objective of this questionnaire was to assess the infection status in the COVID-19 pandemic since December in Henan Province, China, and the prevalence of infection in people who were taking ursodeoxycholic acid (UDCA) during this period. We distributed questionnaires to patients attending the gastroenterology clinic at the First Affiliated Hospital of Henan University of Chinese Medicine. The questionnaire lasted for 3 weeks and a total of 660 were collected, of which the number of people taking UDCA was 70. This is the first investigation into the rate of infection among those taking UDCA during the time of the COVID-19 pandemic. Our results showed that the overall infection rate among those taking UDCA was 71.43% (n = 50), with a 10% (n = 7) rate of asymptomatic infections, which was significantly lower than the 85.42% (n = 504) and 6.27% (n = 37) rates among respondents who did not take. The administration of UDCA showed a trend toward reducing the rate of COVID-19 infection, but the difference was not statistically significant when compared to patients with shorter durations of medication use. While less than 30% of participants remained uninfected during the study period, indicating a potential protective effect, it is important to note that complete prevention of SARS-CoV-2 infection by UDCA was not observed.

West Nile Virus (WNV) infection represents a major global public health challenge. Even though most of the patients are asymptomatic, some cases progress to critical condition which may be fatal. Diagnosis traditionally relies on serological methods, but their limitations, including cross-reactivity, highlight the need for alternative approaches. Here, we present the development and validation of a novel RT-qPCR assay for precise and rapid detection of WNV RNA in urine, emerging as a promising specimen due to its noninvasive collection and high viral load. The assay demonstrates high efficiency and sensitivity, with a detection limit comparable to commercially available kits. This study highlights the importance of in-house kit design as a diagnostic tool in regions affected by emerging tropical infections, such as WNV, exemplified Cyprus. It emphasizes the critical role of low-cost, early detection with high sensitivity and specificity in infection control and surveillance efforts.

Objective: Although metagenomic next-generation sequencing (mNGS) technology has achieved notable outcomes in pathogen detection, there remains a gap in the research regarding its application in predicting the antibiotic resistance of pathogenic bacteria. This study aims to analyze the clinical application value of mNGS in predicting the resistance of carbapenem-resistant Enterobacteriaceae (CRE), as well as the relevant influencing factors, thereby providing valuable insights for clinical antimicrobial therapy. Methods: Nonduplicate isolates of Enterobacterales bacteria collected from Liaocheng People's Hospital from April 2023 to June 2024 were selected, and CRE bacteria were screened. mNGS was used to detect resistance genes, and the results were compared with those of polymerase chain reaction (PCR) to evaluate the specificity and sensitivity of gene detection. Furthermore, the performance of mNGS in identifying pathogenic microorganisms and predicting antibiotic resistance was assessed by comparing the sequencing results with those of antimicrobial susceptibility testing (AST). Results: A total of 46 isolates were confirmed as CRE through traditional AST and were further identified using the Vitek MS and Vitek 2 systems. The results indicated 27 isolates of Klebsiella pneumoniae, 14 isolates of Escherichia coli, 2 isolates of Enterobacter hormaechei, 2 isolates of Enterobacter cloacae, and 1 isolate of Citrobacter freundii. These isolates were subjected to both mNGS and PCR for detection. The calculation of the area under the receiver operating characteristic (ROC) curve demonstrated the reliability of mNGS in detecting resistance genes. Conclusion: mNGS demonstrated high sensitivity in predicting the presence of carbapenemase resistance genes in CRE, showing potential in early indication of isolate resistance information, thereby facilitating timely guidance for clinical treatment strategies.

Introduction: The persistent increase in multidrug-resistant pathogens has catalyzed the creation of novel strategies to address antivirulence and anti-infective elements. Such methodologies aim to diminish the selective pressure exerted on bacterial populations, decreasing the likelihood of resistance emergence. This review explores the role of biofilm formation as a significant virulence factor and its impact on the development of antimicrobial resistance (AMR). Case Presentation: The ability of bacteria to form a superstructure-biofilm-has made resistance cases in the microbial world a big concern to public health and other sectors as it is a crucial virulence factor that causes difficulties in the management of infections, hence enhancing chronic infection occurrence. Biofilm formation dates to about 3.4 billion years when prokaryotes were discovered to be forming them and since then due to evolution and growth in science, they are more understood. Management and Outcome: The unique microenvironments within bacterial biofilms diminish antibiotic effectiveness and help bacteria evade the host immune system. Biofilm production is a widespread capability among diverse bacterial species. Biofilm formation is enhanced by quorum sensing (QS), reduction of nutrients, or harsh environments for the bacteria. Conclusion: The rise of severe, treatment-resistant biofilm infections poses major challenges in medicine and agriculture, yet much about how these biofilms form remains unknown.

Background: Since the SARS-CoV-2 pandemic, many patients have suffered prolonged complications, called "long COVID." Mycoplasma pneumoniae is a common respiratory pathogen. Reports of simultaneous long COVID and M. pneumoniae infections are rare in the literature. Methods: We analyzed the clinical data of patients with long COVID-19 who visited the Respiratory Clinic of The Affiliated Hospital of Hangzhou Normal University between January 1 and January 31, 2023, together with their laboratory and radiographic findings, with Pearson's χ ² test. Results: Fifty-two patients diagnosed with both long COVID and M. pneumoniae infection and 77 with long COVID only were compared. The ages, clinical symptoms, and comorbidities of the two groups did not differ significantly (p > 0.05). However, sex and imaging findings differed between the groups. Conclusions: Our study showed that long COVID-M. pneumoniae coinfection was more commonly seen in females and patients with typical chest computed tomography (CT) images.

Objective: To detect and analyze coronavirus SARS-CoV-2 antibody levels in convalescent plasma from donors who have recovered from COVID-19. Methods: Plasma samples from 88 donors aged 20-54 years who were diagnosed with COVID-19 and who were eligible to donate from Zhejiang Province, China, were collected as the experimental group, and 56 samples from healthy blood donors were used as controls. Anti-SARS-CoV-2 antibodies, including Ab and IgM, were detected via chemiluminescent immunoassay, and neutralizing antibodies were measured via the microneutralization method. Results: The positive rates of total and IgM antibodies against SARS-CoV-2 were 97.7% (86/88) and 52.3% (46/88), respectively, in the plasma samples of 88 patients who recovered from COVID-19. After 160 and 320 dilutions of the total antibody-positive samples, the positive rates were 61.6% (53/86) and 39.5% (34/86), respectively. The titer of neutralizing antibodies was 16-256 in 53 SARS-CoV-2-positive samples after 160-fold dilution of total antibodies. The titer of neutralizing antibody was 48-256 in 34 samples that were still positive after 320-fold dilution of total antibody. Among the 88 samples, 86 had titers > 4, and 10 had high titers > 80. In 2 patients with neutralizing antibody titers < 4, SARS-CoV-2 total antibody and IgM antibodies were negative. The correlation coefficient between total antibody strength and neutralizing antibody titer was 0.5198 (high correlation). The total antibody and IgM antibodies of 56 healthy blood donors were negative. Conclusions: There are individual differences in plasma antibody titers among convalescent patients. Antibody detection is helpful for screening out plasma with high antibody titers for the treatment of patients with severe disease.

Background: Intestinal barrier injury contributes to multiple diseases such as obesity and diabetes, whereas no treatment options are available. Methods: Due to close interactions between mucosal microbiome and intestinal barrier, we evaluated the potential of mucosal bacteria in providing targets for high-fat diet (HFD)-related intestinal barrier injury. Whole-genome metagenomics was used to evaluate mucosal microbiome, while intestinal barrier injury was estimated using serum LPS, FITC-dextran intensity, and ZO-1 protein. Results: We found that HFD induced significant fat accumulation in epididymal tissue at weeks 4 and 12, while ALT, LDL, and TC increased at week 12. Intestinal barrier injury was confirmed by elevated serum LPS at both weeks, upregulated FITC-dextran intensity, and decreased ZO-1 protein at week 12. Fourteen species such as Phocaeicola vulgatus differed in HFD-fed mice. The co-occurrence network of mucosal microbiome shifted from scale-free graph in controls to nearly random graph in HFD-fed mice. Besides, 10 hub bacteria especially Bacteroides ovatus decreased drastically in both mucosal and fecal samples of HFD-fed mice, correlated with intestinal permeability, ALT, and KEGG pathways such as "Mitochondrial biogenesis" and "metabolism". Moreover, Bacteroides ovatus has been confirmed to improve intestinal barrier function in a recent study. Conclusion: Mucosal hub bacteria can provide potential targets for improving HFD-related intestinal barrier function.

Background: Acanthamoeba species are recognized as the most prevalent free-living amoebae (FLA). They can cause granulomatous amebic encephalitis (GAE) and pulmonary and ocular infections. The present study aimed to isolate and identify Acanthamoeba genotypes in cancer patients referred to Kashan's hospitals in Central Iran. Methods: This cross-sectional study was conducted with oral and nasal swab samples collected from a hundred cancer patients referred to Kashan's Beheshti and Yasrebi hospitals during 2019-2020. The samples were cultured in 1.5% non-nutrient agar (NNA) with heat-killed Escherichia coli and examined for "FLA." A polymerase chain reaction (PCR) assay amplifying the 18S rRNA gene was performed, and Acanthamoeba-positive isolates were subjected to nucleotide sequencing to identify their genotypes. Results: The prevalence of Acanthamoeba infection was 51% in the oral cavity and 38% in the nasal samples of cancer patients. The most frequent Acanthamoeba cysts were (51.3%) wrinkled polygonal and sized 9.55-11.5 μm (Group II). Acanthamoeba genotypes T4, T11, and T5 were identified in the oral cavity samples, whereas T4 and T11 were detected in the nasal samples. Conclusion: The prevalence of Acanthamoeba infection in oral and nasal cancer patients was higher in Kashan, Iran, compared to other countries. Due to the high rate of oral Acanthamoeba contamination, oral sampling is recommended for better detection of this protozoan. Since T4 is the predominant genotype that can cause serious diseases in high-risk groups, increasing physicians' awareness of infections associated with Acanthamoeba and preventive and control measures are strongly suggested.