Journal of Microbiology Immunology and Infection最新文献

Background

Real-world vaccine effectiveness following the third dose of vaccination against SARS-CoV-2 remains less investigated among people with HIV (PWH).

Methods

PWH receiving the third dose of BNT162b2 and mRNA-1273 (either 50- or 100-μg) were enrolled. Participants were followed for 180 days until the fourth dose of COVID-19 vaccination, SARS-CoV-2 infection, seroconversion of anti-nucleocapsid IgG, death, or loss to follow-up. Anti-spike IgG was determined every 1–3 months.

Results

Of 1427 participants undergoing the third-dose COVID-19 vaccination, 632 (44.3%) received 100-μg mRNA-1273, 467 (32.8%) 50-μg mRNA-1273, and 328 (23.0%) BNT162b2 vaccine and the respective rate of SARS-CoV-2 infection or seroconversion of anti-nucleocapsid IgG was 246.1, 280.8 and 245.2 per 1000 person-months of follow-up (log-rank test, p = 0.28). Factors associated with achieving anti-S IgG titers >1047 BAU/mL included CD4 count <200 cells/mm³ (adjusted odds ratio [aOR], 0.11; 95% CI, 0.04–0.31), plasma HIV RNA >200 copies/mL (aOR, 0.27; 95% CI, 0.09–0.80), having achieved anti-spike IgG >141 BAU/mL within 3 months after primary vaccination (aOR, 3.69; 95% CI, 2.68–5.07), receiving BNT162b2 vaccine as the third dose (aOR, 0.20; 95% CI, 0.10–0.41; reference, 100-μg mRNA-1273), and having previously received two doses of mRNA vaccine in primary vaccination (aOR, 2.46; 95% CI, 1,75-3.45; reference, no exposure to mRNA vaccine).

Conclusions

PWH receiving different types of the third dose of COVID-19 vaccine showed similar vaccine effectiveness against SARS-CoV-2 infection. An additional dose with 100-μg mRNA-1273 could generate a higher antibody response than with 50-μg mRNA-1273 and BNT162b2 vaccine.

This study investigated antimicrobial resistance in Salmonella enterica serovar Choleraesuis (S. Choleraesuis) isolates from diseased pigs in Taiwan (2015–2020). Among 272 isolates, florfenicol (96.7%), enrofloxacin (96.3%), doxycycline (91.2%), gentamicin (84.6%), and tiamulin (80.5%) exhibited high resistance. 99.3% of the isolates were resistant to at least one antibiotic, and 97.8% of the isolates were multidrug resistant. This study illustrated that S. Choleraesuis isolates exhibited high resistance to antimicrobials currently used in the Taiwanese swine industry.

Introduction

Lung cancer is one of the most prevalent malignancies worldwide. Substantial research has illuminated the intricate interplay between microorganisms and human health, revealing their role in disease regulation. Trichomonads is a flagellated protozoan in the human cavity and have been previously identified as a pathogen associated with pneumonia, contributing to tissue chronic inflammation and carcinogenesis.

Methods

Nested polymerase chain reaction methods were employed to scrutinize the prevalence of trichomonads in the bronchovesicular fluid of patients diagnosed with lung cancer. Subsequently, the influence of Trichomonas tenax invasion on lung cancer cells was elucidated through proliferation assays, migration assays, and transcription analysis.

Results

Bronchoalveolar fluid samples from lung cancer patients yielded positive nested PCR results for eight out of twenty-seven samples. Seven of these samples were identified as Trichomonas tenax, while one was identified as Tetratrichomonas spp. Our findings revealed a significant upregulation of pathways associated with carcinogenesis, including cellular proliferation, migration, and drug resistance, in response to T. tenax invasion.

Conclusions

This study underscores the importance of recognizing the presence of trichomonads and the influence of T. tenax invasion on host responses to respiratory diseases. The identified pathways implicated in cancer development may pave the way for developing targeted treatment strategies for pulmonary diseases. These findings hold promise for informing and improving the precision of therapeutic interventions in the context of pulmonary ailments.

Background

Respiratory syncytial virus (RSV) infection imposes substantial health burden and disproportionally affects young infants, elderly, and immunocompromised hosts. RSV harbors key surface glycoproteins F and G, both crucial for viral infection and evolution.

Methods

In this study, we examined the genetic characteaistics of 179 RSV isolates collected between 2017 and 2021 in Taiwan. G ectodomain and whole F gene were sequenced and aligned with available references from GenBank.

Results

RSV ON1 and BA9 were two predominant genotypes throughout the study period. Genetic variations of G protein accumulated over time. New ON1 strains containing E257K and K204R-V225A-T238I-Y280H in combination emerged in 2019 and contributed to a local endemic in 2020. RSV-B strain with A131T and T137I substitution in G protein emerged in 2018. On the other hand, F protein of both RSV genotypes was generally conserved but some feature changes should be noted: RSV-B in Taiwan harbored 100% of I206M and Q209R in site Ø, and L172Q and S173L in site V. These amino acid changes do not affect the susceptibility of Nirsevimab but imply no effectiveness of Suptavumab.

Conclusion

RSV continuously evolves in Taiwan and accumulated signature genetic changes over time. Vigilant RSV genomic surveillance is important to monitor the viral evolution in the upcoming future of new RSV vaccines and prophylaxis.

Background

The increasing prevalence of drug-resistant pathogens leads to delays in adequate antimicrobial treatment in intensive care units (ICU). The real-world influence of the BioFire FilmArray Blood Culture Identification 2 (BCID2) panel on pathogen identification, diagnostic concordance with conventional culture methods, and antimicrobial stewardship in the ICU remains unexplored.

Methods

This retrospective observational study, conducted from July 2021 to August 2023, involved adult ICU patients with positive blood cultures who underwent BCID2 testing. The concordance between BCID2 and conventional culture results was examined, and its impact on antimicrobial stewardship was assessed through a comprehensive retrospective review of patient records by intensivists.

Results

A total of 129 blood specimens from 113 patients were analysed. Among these patients, a high proportion of drug-resistant strains were noted, including carbapenem-resistant Klebsiella pneumoniae (CRKP) (57.1%), carbapenem-resistant Acinetobacter calcoaceticus-baumannii complex (100%), methicillin-resistant Staphylococcus aureus (MRSA) (70%), and vancomycin-resistant Enterococcus faecium (VRE) (100%). The time from blood culture collection to obtaining BCID2 results was significantly shorter than conventional culture (46.2 h vs. 86.9 h, p < 0.001). BCID2 demonstrated 100% concordance in genotype–phenotype correlation in antimicrobial resistance (AMR) for CRKP, carbapenem-resistant Escherichia coli, MRSA, and VRE. A total of 40.5% of patients received inadequate empirical antimicrobial treatment. The antimicrobial regimen was adjusted or confirmed in 55.4% of patients following the BCID2 results.

Conclusions

In the context of a high burden of drug-resistant pathogens, BCID2 demonstrated rapid pathogen and AMR detection, with a noticeable impact on antimicrobial stewardship in BSI in the ICU.

Background

Mycoplasma genitalium is an emerging etiology of sexually transmitted infections (STIs) with increasing resistance to antimicrobials. Surveillance on the epidemiology of M. genitalium infection and antimicrobial resistance is warranted.

Methods

Between September 2021 and August 2023, people with HIV (PWH) and people without HIV (PWoH) at risk of STIs were screened for M. genitalium infection using a multiplex polymerase-chain-reaction assay of specimens collected from the rectum, urethra, oral cavity, and vagina. The prevalences of resistance-associated mutations (RAMs) of M. genitalium to fluoroquinolones, macrolides, and tetracycline were investigated.

Results

During the 2-year study period, 1021 participants were enrolled, including 531 PWH and 490 PWoH. Overall, 83 (8.1%) and 34 (7.6%) participants had M. genitalium infection at baseline and during follow-up, respectively, with the rectum being the most common site of detection (61.5%). With the first course of antimicrobial treatment, 27 of 63 (42.9%) participants with M. genitalium infection were cured during follow-up, including 24 of 58 (41.4%) who received doxycycline monotherapy. The prevalence of RAMs to macrolides, fluoroquinolones, and tetracyclines at baseline were 24.3%, 22.4%, and 7.9%, respectively. Though PWH had more M. genitalium infection (10.2% vs 5.9%, p = 0.01), a higher rate of RAMs to macrolides (41.0% vs 14.7%, p < 0.01) was found in PWoH.

Conclusions

Among high-risk populations, the prevalence of M. genitalium infection was 8.1%. The overall genotypic resistance of M. genitalium to macrolides and fluoroquinolones was moderately high in Taiwan. Detection of M. genitalium infection and antimicrobial resistance is warranted to ensure resistance-guided antimicrobial treatments to be administered.

The burden of respiratory syncytial virus (RSV) infection among older adults in Taiwan is not well understood due to a scarcity of published epidemiological data. Nonetheless, the increasing proportion of older adults is anticipated to translate to increased burden of RSV infection, presenting a challenge to the healthcare system. Thus, an expert meeting was convened among a panel of infectious disease specialists from Taiwan to evaluate the existing local evidence and data gaps related to RSV infection in older adults (aged ≥50 years), and propose steps to generating evidence on disease burden among this population. Overall, there are few studies on the clinical and economic burden of RSV infection in Taiwan, and existing data are limited by small sample sizes and highly selected populations. Inconsistent RSV testing practices among older adults contribute to under-diagnosis and under-reporting, driven by limitations to reimbursement policies that discourage proactive RSV testing in older adults, and the lack of appropriate, targeted RSV treatment. Crucially, the paucity of epidemiological data may perpetuate a lack of awareness of RSV among clinicians and the public, hinder investments into RSV testing at a policymaker level, and thereby impede implementation of consistent diagnostic practices, precluding a deeper understanding of RSV. To overcome these challenges, it is imperative to prioritize generation of epidemiological data to establish the burden of RSV infection among older adults in Taiwan. Such data would also support a multi-stakeholder group in assessing the impact of future RSV-related interventions, such as educational initiatives and preventative strategies including vaccines.

Background

Co-therapy with albendazole and steroid is commonly used in patients with eosinophilic meningoencephalitis caused by Angiostrongylus cantonensis infections. However, anthelminthics often worsen symptoms, possibly due to the inflammatory reaction to antigens released by dying worms. Therefore, the present study was to investigate the curative effects and probable mechanisms of the platelet-derived growth factor receptor-beta (PDGFR-β) inhibitor AG1296 (AG) and the phosphoinositide 3-kinase inhibitor (PI3K) LY294002 (LY) in A. cantonensis-induced neurovascular unit dysfunction and eosinophilic meningoencephalitis.

Methods

Western blots were used to detect matrix protein degradation and the expressions of PDGFR-β/PI3K signaling pathway. The co-localization of PDGFR-β and vascular smooth muscle cells (VSMCs), and metalloproteinase-9 (MMP-9) and VSMCs on the blood vessels were measured by confocal laser scanning immunofluorescence microscopy. Sandwich enzyme-linked immunosorbent assays were used to test S100B, interleukin (IL)-6, and transforming growth factor beta in the cerebrospinal fluid to determine their possible roles in mouse resistance to A. cantonensis.

Results

The results showed that AG and LY cotherapy decreased the MMP-9 activity and inflammatory reaction. Furthermore, S100B, IL-6 and eosinophil counts were reduced by inhibitor treatment. The localization of PDGFR-β and MMP-9 was observed in VSMCs. Furthermore, we showed that the degradation of the neurovascular matrix and blood-brain barrier permeability were reduced in the mouse brain.

Conclusions

These findings demonstrate the potential of PDGFR-β inhibitor AG and PI3K inhibitor LY co-therapy as anti-A. cantonensis drug candidates through improved neurovascular unit dysfunction and reduced inflammatory response.

Introduction

COVID-19 poses risks and leads to complications for vulnerable populations, including children. Unreported cases of COVID-19 among children hinder our understanding of the true disease burden. In this study, we aimed to investigate the proportion of children who report no prior infection to SARS-CoV-2 but who nevertheless exhibit serological evidence of prior infection.

Methods

Between November 2022 and February 2023, we recruited children and adolescents under 19 years of age who lacked a prior history of SARS-CoV-2 infection. Participants underwent SARS-CoV-2 antibody testing to assess the presence of IgG antibodies specific to nucleocapsid (N) and spike (S) proteins. Demographic and contact information were also collected.

Results

Among 260 COVID-19-free children, the overall anti-N antibody positivity rate, which varied across age groups (4%–25%), was 9.2% (24/260). Contact with individuals who were positive for COVID-19, particularly the children's mothers, significantly increased the likelihood of antibody positivity. The median age of the 34 children who remained unvaccinated against COVID-19 was lower than that of the children who were vaccinated (6.5 vs. 9 years; p < 0.001). Until January 2024, the overall infection rate was 41.9% (99/236) among children who were negative for anti-N antibodies, irrespective of vaccination status or the presence of chronic disease.

Conclusion

We discovered previously undisclosed cases of SARS-CoV-2 infection among children. The risk of seropositivity increases substantially with household contact. Regarding children who report no prior exposure to COVID-19, clinicians must remain vigilant, as SARS-CoV-2 remains a concern.

Background

Urine leukocyte count under microscopy is one of the most frequently used routine screening tests for urinary tract infection (UTI). Nevertheless, it is observed that pyuria is lacking in 10-25% of children with UTI. This study aims to determine the factors related to pyuria-negative UTI in young infants aged under four months old.

Method

This retrospective cross-sectional study was conducted on 157 patients aged under 4 months old with UTI. All subjects had paired urinalysis and urine culture, which were collected via transurethral catheterization. According to the results of their urinalysis, the patients were then classified as UTI cases with pyuria and UTI cases without pyuria. The clinical characteristics and outcomes of both groups were analyzed.

Result

Among the 157 UTI patients, the prevalence of pyuria-negative UTI was 44%. Significant risk factors associated with pyuria-negative UTI included non-E.coli pathogens, younger age, shorter duration of fever prior to hospital visit, lower white blood cell (WBC) count upon hospital visit, and absence of microscopic hematuria.

Conclusions

We found that non-E.coli uropathogens were the strongest factor related to pyuria-negative UTI. The absence of pyuria cannot exclude the diagnosis of UTI in young infants, and it’s reasonable to perform both urinalysis and urine culture as a part of the assessment of febrile or ill-looking young infants.