Canadian Journal of Infectious Diseases & Medical Microbiology最新文献

Persistent infection with human papillomavirus (HPV) types 31 and 33 is an important causative factor for cervical cancer. The E6/E7 genes are key oncogenes involved in the immortalization and transformation of human epithelial cells. Genetic polymorphism may lead to differences in the virus' carcinogenic potential, the immune reaction of the host, and the potencies of vaccines. Few studies on HPV31/33 E6/E7 genetic polymorphism have been carried out. To study the genetic polymorphism of HPV31 and HPV33 E6/E7 genes in northeast China, these genes (HPV31 E6/E7, n = 151; HPV33 E6/E7, n = 136) were sequenced and compared to reference sequences (J04353.1, M12732.1) using BioEdit. Phylogenetic trees were constructed by the neighbor-joining method using MegaX. The diversity of the secondary structure was estimated using the PSIPred server. The positively selected sites were analyzed using PAML4.9. The major histocompatibility complex (MHC) class I and MHCII epitopes were predicted using the ProPred-I server and ProPredserver. B-cell epitopes were predicted using the ABCpred server. In the 151 HPV31E6 sequences, 25 (25/450) single-nucleotide mutations were found, 14 of which were synonymous mutations and 11 were nonsynonymous. In the 151 HPV31E7 sequences, 8 (8/297) nucleotide mutations were found, 3 of which were synonymous mutations and 5 were nonsynonymous. In the 136 HPV33E6 sequences, 17 (17/450) nucleotide mutations were observed, 7 of which were synonymous mutations and 10 were nonsynonymous. C14T/G (T5I/S) was a triallelic mutation. Finally, in the 136 HPV33E7 sequences, 9 (9/294) nucleotide mutations were observed, 3 of which were synonymous mutations and 6 were nonsynonymous. C134T/A (A45V/E) and C278G/A (T93S/N) were triallelic mutations. Lineage A was the most common lineage in both HPV31 and HPV33. In all of the sequences, we only identified one positively selected site, HPV33 E6 (K93N). Most nonsynonymous mutations were localized at sites belonging to MHC and/or B-cell predicted epitopes. Data obtained in this study should contribute to the development and application of detection probes, targeted drugs, and vaccines.

Multidrug-resistant pathogens are one of the common causes of death in burn patients and have a high risk of nosocomial infections, especially pneumonia, urinary tract infections, and cellulitis. The role of prolonged hospitalization and empirical antibiotics administration in developing multidrug-resistant pathogens is undeniable. In the early days of admitting burn patients, Gram-positive bacteria were the dominant isolates with a more sensitive antibiotic pattern. However, the emergence of Gram-negative bacteria that are more resistant later occurs. Trustworthy guideline administration in burn wards is one of the strategies to prevent multidrug-resistant pathogens. Also, a multidisciplinary therapeutic approach is an effective way to avoid antibiotic resistance that involves infectious disease specialists, pharmacists, and burn surgeons. However, the emerging resistance to conventional antimicrobial approaches (such as systemic antibiotic exposure, traditional wound dressing, and topical antibiotic ointments) among burn patients has challenged the treatment of multidrug-resistant infections, and using nanoparticles is a suitable alternative. In this review article, we will discuss different aspects of multidrug-resistant pathogens in burn wounds, emphasizing the full role of these pathogens in burn wounds and discussing the application of nanotechnology in dealing with them. Also, some advances in various types of nanomaterials, including metallic nanoparticles, liposomes, hydrogels, carbon quantum dots, and solid lipid nanoparticles in burn wound healing, will be explained.

Dengue fever is a viral infection caused by the dengue virus and is a growing concern for public health worldwide, particularly in tropical and subtropical regions. This study aimed to assess the diagnostic accuracy of a commercially available NS1 ELISA kit for dengue fever in Pakistan using multiplex qRT-PCR as the gold standard. The study recruited 1236 suspected cases of dengue fever admitted to public sector hospitals in Lahore, Pakistan. Of the suspected cases, 610 (49.3%) were confirmed positive for DENV infection through qRT-PCR, with all four serotypes detected. DENV-2 was the most prevalent serotype, detected in 95.7% of cases. The NS1 ELISA kit detected 71.1% of the positive cases. However, the diagnostic accuracy of the NS1 ELISA kit was found to be only 64.89%. Of the 610 confirmed cases, 68% were male and 32% were female, with a median age of 30 years. Dengue fever was diagnosed in 91.8% of cases, while 8.2% were diagnosed with dengue hemorrhagic fever (DHF). DHF patients had a higher prevalence of abdominal pain, hemorrhagic manifestations, and thrombocytopenia. The cocirculation of all four DENV serotypes in Lahore is concerning and could lead to more severe forms of the disease, such as DHF or dengue shock syndrome, in the future. The study highlights the low diagnostic accuracy of commercially available NS1 ELISA kits and emphasizes the importance of using molecular methods to confirm acute dengue infections. Given the increasing prevalence of dengue fever in developing countries like Pakistan, more accurate and reliable diagnostic tools are needed for effective disease management and control.

Background: The livestock sector contributes 1.90% to the GDP in Bangladesh during 2021-22. Poultry is one of the important subsectors struggling with diseases. Fowl adenoviruses (FAdVs) cause numerous diseases resulting in economic losses to the poultry industry worldwide. Several FAdV serotypes cause inclusion body hepatitis in chicken. Although FAdV infection was suspected, there was no confirmatory report from Bangladesh. The study was conducted to investigate the FAdV infection and antibodies in chicken.

Methods: A total of 50 samples, each composed of liver and spleen, were collected from different chickens of Gazipur, Dinajpur, and Panchagarh district. Each location belongs to A, B, and C poultry zones of Bangladesh, respectively. Viruses were detected by real-time PCR and conventional PCR. Blood samples (n = 303) were collected at the beginning and after the recovery from infection and tested by indirect ELISA. Sequencing of PCR products was done for serotyping and phylogenetic analysis.

Results: Clinical signs were observed including anorexia, drowsiness, ruffled feathers, reduced body weight, lack of uniformity, and high mortality (15-25%). Enlarged friable liver with yellow to tan color mottled with the focal soft area, fluid in pericardial sac, swollen and hemorrhagic kidneys, enlarged congested spleen and pancreas, etc. were found on postmortem examination. FAdVs were detected in 90% of the flocks except commercial layer flock from Dinajpur. Three serotypes, namely, 8b (70%), 11 (10%), and 5 (10%) were detected. Anti-FAdV antibody was detected in 80% flocks at the beginning of infection and in 90% of the flocks after recovery from infection. The antibody titer increases significantly (p < 0.05) after recovery from infection. Phylogenetic analysis revealed that the Bangladeshi FAdVs have close identity with viruses from Asia, Europe, and South and North America.

Conclusions: These findings suggested that several introductions of FAdVs were taken place in Bangladesh. To combat the disease, vaccination along with maintenance of biosecurity is essential.

The death because of meningitis remains high in some parts of the world. It is important to know the specific cause of meningitis because the treatment differs depending on the cause. This study aimed to trace the false-negative results of multiplex RT-PCR to detect Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis serogroup by two different molecular methods. In this study, the CSF of the suspicious pediatric for acute bacterial meningitis among children aged 1 month to 14 years who are admitted to the hospitals in four cities of a certain region of Iran was collected. S. pneumoniae, H. influenzae, and N. meningitidis in CSF samples were detected by single-tube multiplex RT-PCR and specific RT-PCR with a probe on the same specimens. In this cross-sectional study, 506 CSF samples were collected during one year. The multiplex RT-PCR can detect 3.3% and 2.2% of S. pneumoniae and H. influenzae, respectively. N. meningitidis was not detected. The CSF analysis was abnormal in 53% of 506 patients. On the other hand, 11.5%, 4.8%, and 4.1% of S. pneumoniae, H. influenzae, and N. meningitidis were identified, respectively, by specific RT-PCR assay, exactly on the same specimens. Various types of PCR can be used for pathogen identification. As we change the type of PCR in our study, we could approximately increase 15% our positive results and also consequently decrease our false-negative responses.

Background: During the COVID-19 pandemic, public transport was restricted in many countries because of the transmission risk. According to the risk compensation theory, travellers post-COVID-19 vaccination may encounter higher risks; however, no real-world studies provide such evidence. Therefore, we conducted a survey to assess whether risk compensation would occur among travellers' health-related behaviours after COVID-19 vaccination, potentially aggravating the transmission of the virus.

Materials and methods: A self-administered online survey was designed and distributed over WeChat to identify the difference in health behaviours before and after COVID-19 vaccination among travellers at a train station in Taizhou, China, from 13 February to 26 April 2022.

Results: A total of 602 individuals completed the questionnaire. The results revealed no statistical difference between the health behaviours reported by the vaccinated and unvaccinated groups. Participants who received the first dose of the vaccine earlier showed no statistical difference in harmful health behaviours (hand washing frequency decreased by 4.1% (P=0.145) and the duration of public transport travel increased by 3.4% (P=0.437)), but showed better protective health behaviours (mask-wearing duration increased by 24.7% (P=0.014)). Compared to those vaccinated less than three times, participants vaccinated against COVID-19 three times showed no statistical differences in harmful health behaviours mask-wearing duration decreased by 7.0% (P=0.927), their hand washing frequency decreased by 4.8% (P=0.905), and the duration of public transport travel increased by 2.5% (P=0.287). After vaccination, when compared to themselves before vaccination, participants exhibited better health behaviours (increased hand washing frequency and mask-wearing duration, and decreased duration of public transport travel) to some extent.

Conclusion: In conclusion, this study found no evidence of risk compensation among travellers. After being vaccinated, health behaviours partly improved among travellers.

Background: Cocirculation of influenza (Flu) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (SARS-CoV-2/Flu) represent a public health concern as it may worsen the severity and increase fatality from coronavirus disease 2019. An increase in the number of patients with coinfection was recently reported. We studied epidemiology, severity, and outcome of patients with SARS-CoV-2/Flu coinfection seen at Egypt's integrated acute respiratory infections surveillance to better describe disease impact and guide effective preventive measures.

Methods: The first two outpatients were seen daily, and every fifth patient admitted to 19 sentinel hospitals with respiratory symptoms was enrolled. Patients were interviewed using a standardized questionnaire and provided nasopharyngeal swabs to be tested for SARS-CoV-2 and influenza by real-time polymerase chain reaction at the central laboratory. Data from all patients with coinfection were obtained, and descriptive data analysis was performed for patients' demographics, clinical course, and outcome.

Results: The total number of patients enrolled between January 2020 and April 2022 was 18,160 and 6,453 (35.5%) tested positive for viruses, including 52 (0.8%) coinfection. Of them, 36 (69.2%) were coinfected with Flu A/H3, 9 (17.3%) Flu-B, and 7 (13.5%) Flu A/H1. Patients' mean age was 33.2 ± 21, 55.8% were males, and 20 (38.5%) were hospitalized, with mean hospital days 6.7 ± 6. At the hospital, 14 (70.0%) developed pneumonia, 6 (30.0%) ICU admitted, and 4 (20.0%) died. The hospitalization rate among patients coinfected with Flu-B and Flu A/H3 was 55.6 and 41.7%, with mean hospital days (8.0 ± 6 and 6.4 ± 6), pneumonia infection (40.0 and 80.0%), ICU admission (40.0 and 26.7%), and death (20.0% for both), while no patients hospitalized with A/H1.

Conclusions: The recent increase in the number of SARS-CoV-2/Flu coinfections was identified in Egypt. The disease could have a severe course and high fatality, especially in those coinfected with Flu-B and Flu A/H3. Monitoring disease severity and impact is required to guide preventive strategy.

The early detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the real-time quantitative polymerase chain reaction (RT-qPCR) as a gold-standard molecular tool has allowed to test and trace the viral spread and the isolation of COVID-19-infected patients. The detection capacity of viral and internal genes is an essential parameter to consider and analyze during the assay. In this study, we analyze the performance of the two commercial RT-qPCR kits used in Chile, TaqMan™ 2019-nCoV Control Kit v1 (Thermo Fisher) and MaxCov19 (TAAG Genetics), for the COVID-19 diagnosis from nasopharyngeal swab samples (NPSs). Our results show a lower sensitivity of the TAAG kit compared to the Thermo Fisher kit, even in the detection of SARS-CoV-2 mutations associated with its variants. This study reinforces the relevance of evaluating the performance of RT-qPCR kits before being used massively since those with lower sensitivity can generate false negatives and produce outbreaks of local infections.

Background: Cystic fibrosis (CF) is an inherited recessive disorder characterized by recurrent and persistent pulmonary infections, resulting in lung function deterioration and early mortality.

Methods: A cross-sectional study was conducted on the bacterial profile and antibiotic resistance pattern of 103 respiratory specimens from CF patients with signs of pulmonary exacerbation. Antibiotic susceptibility testing and biofilm formation of Staphylococcus aureus and Pseudomonas aeruginosa isolates were performed by the Kirby-Bauer disc diffusion method and microtiter plate assay, respectively. Molecular typing of S. aureus and P. aeruginosa isolates was carried out by spa typing and repetitive extragenic palindromic element PCR.

Results: In a total of 129 isolates, the most prevalent organisms were S. aureus (55.3%) and P. aeruginosa (41.7%). Other less prevalent bacterial isolates include coagulase-negative staphylococci, Escherichia coli, klebsiella spp., Enterobacter spp., and Achromobacter xylosoxidans. The highest rate of resistance for S. aureus was observed to azithromycin and erythromycin (80%), ciprofloxacin (52.3%), clindamycin (44.6%) and tetracycline (43%). Twenty percent of S. aureus isolates were methicillin-resistant S. aureus (MRSA) and 47.6% were MDR S. aureus. For P. aeruginosa isolates the highest resistance was to cefepime (38.3%) and levofloxacin (33.3%) and 20% showed MDR phenotype.

Conclusion: Our study demonstrated a significant decline in the prevalence of P. aeruginosa infections in comparison to previous studies. We found S. aureus to be more prevalent in younger patients, whereas mucoid P. aeruginosa showed a shift in prevalence toward older ages. Molecular typing methods showed great diversity between isolates.

Erythrasma is a chronic infection of the skin that appears in the body folds as flat copper spots. The causative agent of this infection is Corynebacterium minutissimum (C. minutissimum). Erythrasma can be treated with antiseptics or topical antibiotics. The study aimed to investigate the antibiotics susceptibility patterns, and the presence of the erythromycin resistance gene (ermX and mefA) in C. minutissimum isolates in skin lesions with suspected erythrasma. From July 2020 to May 2022, 278 skin scrub specimens were collected from patients admitted to the hospital of Tabriz University of Medical Sciences. Specimens were incubated on the blood agar plates and isolates were identified by microbiological laboratory methods. The antibiotic susceptibility patterns were determined by the disk diffusion method and resistance genes of ermX and mefA were detected by the PCR method. Out of 278 specimens, 41 C. minutissimum isolates (14.74%) were recovered. The highest frequency of resistance was observed to a penicillin (75.6%) followed by erythromycin and clarithromycin (39.02%), clindamycin (30.05%), tetracycline (24.2%), and gentamicin and neomycin (19.5%). The frequencies of ermX and mefA genes were 75% and 12.5%, respectively. Resistance to antimicrobial drugs was common and worrying. Resistance to erythromycin in C. minutissimum is mainly related to the ermX gene.