Canadian Journal of Infectious Diseases & Medical Microbiology最新文献

Aim: To analyze the clinical characteristics, antimicrobial therapies, and outcomes of neonates with carbapenem-resistant Enterobacteriaceae (CRE) bloodstream infections.

Methods: This single-center retrospective study included 22 neonates with CRE bloodstream infections at a tertiary children's hospital in China (September 1, 2019-August 31, 2024). Data of clinical characteristics, risk factors, pathogens, carbapenemase testing, antimicrobial therapy, and outcomes were analyzed.

Results: All 22 neonates had hospital-acquired late-onset infections (males, 77.3%; preterm infants, 81.8%). Prior to onset, 72.7% of the neonates had a history of broad-spectrum antibiotic exposure. Klebsiella pneumoniae was the predominant pathogen (91.9%). Eighteen isolates underwent carbapenemase testing, with KPC being the most prevalent carbapenemase (66.7%). The antimicrobial agents were changed for 8 infants based on the carbapenemase testing results. Six neonates with KPC-producing CRE infections received ceftazidime-avibactam (CAZ-AVI), and two neonates with NDM-producing CRE infections were treated with CAZ-AVI plus aztreonam. All 20 neonates who completed full treatment achieved clinical cure, while two neonates succumbed to infection before effective therapy initiation. The all-cause mortality rate was 13.6%.

Conclusion: Neonates with immature immunity are more susceptible to CRE bloodstream infections, but clinical cure could be achieved after effective antimicrobial therapy. Carbapenemase testing plays a crucial role in the decision making on treatment of neonatal CRE infections.

Background: Pertussis is an acute respiratory infectious disease caused by Bordetella pertussis, which can lead to respiratory failure and death in severe cases. In recent years, pertussis incidence has risen globally, especially in children, due to waning vaccine immunity and mutations in the pertussis bacteria. This study aimed to retrospectively analyze the clinical features, treatment regimens, and economic evaluation of pertussis in children to explore the impact of different treatments on disease outcomes.

Methods: This study collected clinical data from 76 children with pertussis treated in our hospital from January 2024 to December 2024. The patients were divided into severe and nonsevere groups based on their condition. The clinical data, drug treatments, hospitalization costs, and hospital stays were compared between the two groups to evaluate the efficacy and economic impact of different treatments.

Results: The study found that the highest incidence of pertussis occurred in infants aged 6 weeks to 3 months. Severe pertussis cases had significantly longer hospitalization times, treatment durations, and antibiotic therapy courses than the nonsevere group. Macrolide antibiotics remain the first-line treatment, but resistance to these drugs has emerged in certain regions, making sulfamethoxazole-trimethoprim (SMZ-TMP) an effective alternative. Steroid treatment was effective in symptom relief but did not affect cure rates or recurrence.

Conclusion: This study shows that pertussis remains common in infants, with severe cases presenting greater treatment challenges. For children with macrolide-resistant pertussis, SMZ-TMP shows good efficacy. Proper selection of antibiotics and symptomatic treatment are essential for improving patient outcomes and reducing complications.

Background: Frequently touched objects within hospital premises acts as a potential reservoir for healthcare-associated infections (HCAIs), significantly amplifying the risk when biofilm-producing bacteria are involved. These bacteria often exhibit multidrug-resistant (MDR) patterns, complicating the antimicrobial treatments. So, this study intended to determine the bacterial contamination level on frequently touched objects and their antibiotic susceptibility patterns and to determine the relation between biofilm-producing Staphylococcus aureus and multidrug resistance patterns.

Methods: A hospital-based cross-sectional study was conducted at different intensive care units (NICU and MICU) and operation theatre of Frontline Hospital, Kathmandu, Nepal. Aseptically, 297 swab samples were collected and cultured, and the isolated bacteria were identified using standard microbiological procedures. Antibiotics susceptibility test done by the Kirby-Bauer disc diffusion method, and biofilm detection was done by the microtiter plate method at 570 nm by using an ELISA reader. For data analysis, SPSS Version 23 was used.

Results: Of total 297 swab samples processed, 31.3% (93/297) showed bacterial growth, yielding a total of 108 isolates. Mixed growth was reported on 16.1% (15/93) samples. The frequency of Gram-positive and Gram-negative bacteria was 95.4% (103/108) and 4.6% (5/108), respectively. The main isolates were coagulase-negative staphylococci (CoNS) 50.9%, followed by S. aureus (36.1%), Gram-positive bacilli (8.3%), Pseudomonas species (2.8%), and Klebsiella species (1.9%). Out of 39 S. aureus isolates, 53.8% (21/39) were MDR and 25 (64.10%) were biofilm producers. Similarly, 35.9% (14/39) were methicillin-resistant S. aureus (MRSA), among which majority 71.4% (10/14) of MRSA recovered as biofilm producers.

Conclusion: A frequently touched object within different intensive care units and operation theatre was found to be contaminated with potential pathogens and normal flora. Bacterial contamination of such objects can contribute to HCAIs and the hands of health professionals can be the mode of cross-contamination.

Introduction: COVID-19, caused by SARS-CoV-2, emerged as a global pandemic in late 2019, leading to significant health and societal impacts. Treatment challenges have emerged as a result of viral mutations and the strain on healthcare resources, further intensified by the consequences of long-term COVID-19. Recent studies suggest pomegranate (Punica granatum) may offer immunomodulatory and antiviral benefits attributed to its polyphenol content. This study aimed to evaluate the impact of pomegranate tea on the clinical characteristics of COVID-19 patients and investigate its potential therapeutic role.

Methods: This double-blinded randomized clinical trial evaluated the clinical characteristics of hospitalized COVID-19 patients. Pomegranate was sourced and processed into a standardized aqueous extract, with a placebo prepared to match its appearance. Eligible participants with confirmed COVID-19 pneumonia were randomized into intervention and placebo groups based on their respiratory support needs. Both groups received treatment during their hospital stay and continued postdischarge until symptom resolution. Standard treatment protocols were followed for all participants.

Results: This double-blinded randomized clinical trial evaluated the clinical characteristics of 66 hospitalized COVID-19 patients. The median age of participants was 56 years, and demographics were similar across groups. Notably, 58.7% had symptom onset within the last 10 days. There were statistically significant differences in baseline laboratory markers or primary outcomes, including hospitalization duration and time to improvement. Secondary outcomes similarly demonstrated no significant differences in mortality, respiratory support duration, severity of clinical symptoms, or adverse effects.

Conclusion: This study finds no significant advantage of pomegranate tea in managing COVID-19 but highlights the inherent challenges in researching emerging infectious diseases. Our research highlights the necessity of continuously refining methodologies and adapting to the dynamic nature of emerging pathogens. Such efforts are essential for advancing the search for effective treatments and ultimately enhancing patient care. These findings contribute critically to the ongoing exploration of therapeutic strategies against viral infections, fostering a deeper understanding of potential interventions. Trial Registration: Iranian Registry of Clinical Trials: IRCT20200416047104N1.

Background: Recent advances in detecting respiratory pathogens have allowed for the simultaneous identification of multiple agents, enabling quick and accurate diagnosis to start timely treatment. This study aimed to design a novel two-dimensional (2D) multiplex reverse transcription quantitative PCR (RT-qPCR) assay. This assay allows for the concurrent detection of SARS-CoV-2, RSV, and Influenza A-B using molecular beacon technology in a single-well format.

Methods: We used 550 nasopharyngeal swab samples from the Kocaeli University, Research and Educational Hospital, PCR laboratory, along with synthetic plasmids for SARS-CoV-2, RSV, Influenza A-B, and internal control (RNase P). DNA products generated after amplification interacted with intermediate probes containing specific enzymatic cleavage sites and fluorescent markers, producing characteristic melting temperature (Tm) values for melting curve analysis.

Results: Distinct Tm values were identified for SARS-CoV-2 (72°C), RSV (66°C), Influenza A (56°C), Influenza B (68°C), and internal control (80.5°C). The accuracy was confirmed by testing laboratory-confirmed samples and synthetic plasmids, with no cross-reactivity or false positives observed.

Conclusions: This melting curve-based assay can differentiate among various pathogens within a single well and fluorescence channel by utilizing the unique Tm of each target. Consequently, this novel assay may serve as a cost-effective, high-throughput PCR testing method compared to traditional diagnostics.

Infant-type bifidobacteria exhibit potential as targeted biocontrol agents against Listeria monocytogenes infections. However, the strain-specific antimicrobial efficacy and molecular mechanisms remain insufficiently characterized. In this study, the probiotic potential of five bifidobacteria strains was systematically evaluated through comprehensive in vitro antioxidant and antibacterial activities. Furthermore, RNA-seq analysis was employed to elucidate the global transcriptomic responses of L. monocytogenes during coculture with three selected bifidobacteria strains. The results revealed that the tested bifidobacteria strains possess significant in vitro antioxidant and antibacterial activities. Notably, three infant-type bifidobacteria strains exhibited particularly potent growth inhibition against L. monocytogenes. Co-incubation with these strains significantly reduced the survival of L. monocytogenes and modulated the expression of key genes. A substantial proportion of differentially expressed genes (DEGs) were enriched in pathways related to anion binding, ABC transporters, quorum sensing, peptidoglycan biosynthesis, and glutathione metabolism, suggesting common mechanisms underlying the inhibitory effects of infant-type bifidobacteria strains. Furthermore, several virulence-associated DEGs, including ahpC, clpC, clpX, recN, arlR, rpoD, tlyA, and hlyIII, were identified as shared antagonistic targets. Strain-specific DEGs, such as msrB, amiE, clpE, and clpL, were also identified, reflecting variations in virulence inhibition and stress-response mechanisms. These findings advance our understanding of probiotics-pathogen interactions and provide a foundation for developing targeted strategies to combat L. monocytogenes.

Bloodstream infections (BSIs) remain a global health threat with high mortality, compounded by shifting pathogen distributions and rising antimicrobial resistance. It is vitally important to clarify the epidemiology and antibiotic resistance transition of BSI pathogens. This retrospective study analyzed clinical data, pathogen profiles, and antimicrobial susceptibility of BSI inpatients from 2019 to 2023 in Xiangyang, China. Among 2312 isolates, Gram-negative bacteria (52.4%) predominated over Gram-positive bacteria (45.5%), with fungi comprising 2.1%. The prevalence of Gram-negative bacteria showed an increasing trend, while that of Gram-positive bacteria declined. Predominant pathogens included Staphylococcus hominis, Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Notably, 37 cases of polymicrobial BSIs were identified. S. aureus, E. coli, and K. pneumoniae exhibited high resistance to most common antibiotics. Although resistance rates of methicillin-resistant S. aureus and carbapenem-resistant K. pneumoniae have decreased, they remain substantial. Conversely, carbapenem-resistant E. coli prevalence increased annually. The microbes causing BSI are diverse, with varying epidemic characteristics and antibiotic resistance trends. Continuous monitoring of BSI pathogen epidemiology and resistance trends is essential to guide empirical therapy and control resistant strain transmission.

Background: Chlamydia trachomatis is the leading cause of sexually transmitted infections globally, responsible for various conditions including trachoma, genital infections, lymphogranuloma venereum, reactive arthritis, pneumonia, and neonatal conjunctivitis. This bacterium has 19 identified genotypes. This study aimed to evaluate the prevalence and genotype characterization of genital Chlamydia among women of reproductive age in both trachoma-endemic and nonendemic regions of Tanzania.

Methods: From May 2022 to May 2023, we conducted a cross-sectional study involving 400 women attending antenatal and child health clinics in district hospitals located in trachoma-endemic and nonendemic areas. Endocervical swabs were collected, and DNA was extracted for analysis. Polymerase chain reaction (PCR) was used to amplify the ompA gene, and the resulting PCR products were sequenced and compared with reference sequences from GenBank using BLAST to identify genotypes.

Results: The prevalence of genital Chlamydia was 2.3% (9 cases). The genotypes detected were L1 and F, each accounting for 11.1% of the cases. The infection rate was particularly high among women aged 25 years or younger.

Conclusion: The study found a significant prevalence of Chlamydia trachomatis among young women (≤ 25 years) and identified genotypes F and L1. These results highlight the need for ongoing surveillance and targeted public health strategies to manage and prevent Chlamydia infections, particularly among young women in both trachoma-endemic and nonendemic regions of Tanzania.

Background: Malaria and soil-transmitted helminth (STH) co-infection have serious public health implications, especially in the sub-Saharan African region, affecting pregnant women. These infections during pregnancy may lead to anemia, which could cause maternal and perinatal complications.

Objective: To assess the prevalence of malaria and STH co-infection and its association with anemia among pregnant women visiting Mizan-Tepi University Teaching Hospital (MTUTH) from September 1 to December 30, 2024.

Methods: An institution-based cross-sectional study was conducted from September 1 to December 30, 2024, among pregnant women attending antenatal care at MTUTH. Blood and stool samples were collected from each pregnant woman using a systematic random sampling method. Sociodemographic and clinical data were collected using a prestructured questionnaire. Bivariate and multivariable logistic regression analyses were used to determine the association between malaria-STH co-infections and anemia. Data entry and analysis were done using Epi-data Version 4.6 and SPSS Version 27.0. A p value ≤ 0.05 was considered statistically significant.

Result: The following prevalences were recorded: malaria (24.4%, 81/332), STHs (33.7%, 112/332), and their co-infection (12.7%, 42/332). The overall prevalence of anemia was 57.5%, while it was 18.4%, 26.2%, and 9.6% for pregnant women infected with malaria, STH, and co-infection, respectively. Handwashing practice before meals and residence (rural) showed a significant association with malaria-STH co-infection with (AOR = 12.748, p = 0.010) and (AOR = 2.459, p = 0.001), respectively. Washing vegetables and fruits before eating has been shown to have an association with malaria-STH co-infection (AOR = 12.420, p = 0.017) and (AOR = 0.240, p = 0.004), respectively.

Conclusion: The prevalence of malaria, STHs, and their co-infections was high, contributing to the high prevalence of anemia among the study participants. Malaria and STH infection showed a strong statistical association with anemia.

The Elecsys SARS-CoV-2 antigen test (Elecsys; Roche Diagnostics, Rotkreuz, Switzerland) is a quantitative test for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen. Although the positive predictive value of the test is high, false-positive (FP) results are unavoidable. Furthermore, FP results can lead to unnecessary isolation of patients or exposure of FP patients to truly positive patients. Therefore, to minimize potential harm to FP patients, this study aimed to identify clinical cases that are likely to produce FP results and in which additional testing should be recommended. These recommendations should be based on the Elecsys test results and relevant clinical information. Correspondingly, a retrospective study was conducted using nasopharyngeal swab samples from symptomatic and asymptomatic patients with SARS-CoV-2 infection and patients who had close contact with a confirmed SARS-CoV-2 infection case between September 2021 and October 2023. Of the total 5989 samples, 302 tested positive in the Elecsys test. Thereafter, the reverse transcription-polymerase chain reaction test was performed on patient samples (n = 54) with positive Elecsys test results without clinical information consistent with coronavirus disease 19 (COVID-19). A total of 37 of these samples were FP results, and all FP samples showed Elecsys test values near the cutoff index (COI) value. Accordingly, when the Elecsys test yields a low COI value, and the clinical presentation is inconsistent with COVID-19, additional confirmatory testing is recommended.