Journal of Microbiology Immunology and Infection最新文献

Background: Multidrug-resistant Klebsiella pneumoniae (MDR-KP) leads global health concerns as an infectious agent due to many virulence factors, including biofilm formation. The growing urgency for alternative treatment strategies beyond antibiotics has renewed interest in bacteriophages. Pathogen evolution is dynamic and can lead to phage resistance.

Methods: Bacteriophages were isolated from environmental sources and screened against a panel of 280 MDR- K. pneumoniae clinical isolates (74 from 2018 to 2020 and 167 from 2022-23 and 39 environmental KP isolates). Phages were grouped by host range and DNA fingerprinting. Five candidate phages with unique and broad host coverage were selected for further characterization and genome sequencing.

Results: Five candidate phages exhibited diverse host range patterns, strong bacteriolytic activity and significant antibiofilm activity even at low multiplicity of infection. Whole genome sequencing analysis revealed phage KPØ6 to be a novel Taipevirus species with low intergenomic similarity to known phages, and it showed the broadest host range on isolates from the 2018-2020 panel. A significant rise in phage resistance among MDR-KP isolate panels of 2018-2020 and 2022-2023 was observed.

Conclusion: Lytic bacteriophages offer a promising alternative for tackling MDR-KP infections, especially within healthcare environments. The phages characterized in this study demonstrate strong potential for both biocontrol and therapeutic use against MDR-KP, including infections involving biofilms. However, the dynamic nature of bacterial evolution over five years reiterates the need to update phage banks.

Objectives: Diagnosing paediatric Community-Acquired Pneumonia (CAP) is challenging due to the difficulty in obtaining lung specimens. Studies suggest that the upper-airway density of Streptococcus pneumoniae is related to the risk and severity of CAP. We studied the association between S. pneumoniae and its density in the upper airways with CAP and its severity. Additionally, we examined the relationship between respiratory viral load and severe CAP.

Methods: Seven hundred fifteen children with radiologically confirmed CAP and 673 controls were enrolled over 11 years. Nasopharyngeal aspirates (NPA) were tested for 20 viruses and bacteria using semi-quantitative polymerase chain reaction (PCR). NPAs positive for S. pneumoniae were further analysed by quantitative PCR. Adjusted odds ratios (aORs) and 95 % confidence intervals (CIs) were calculated to assess the association between S. pneumoniae density and CAP and CAP severity.

Results: Fewer cases than controls were colonised with S. pneumoniae (culture: 37.6 % vs 51.9 %, p < .001; PCR: 55.3 % vs 69.1 %, p < .001), and the median density was lower (6.20 log¹⁰ copies/mL vs 6.62 log¹⁰ copies/mL, p < .001). No association was found between S. pneumoniae density and CAP severity. CAP severity was significantly associated with high Respiratory Syncytial Virus (RSV) load (aOR 2.26, 95 % CI 1.43-3.57, p < .001) or high Human Metapneumovirus (HMPV) load (aOR 4.32, 95 % CI 2.19-8.48, p < .001), adjusted by pneumococcal density, other pathogens, age, sex, comorbidities, prior antibiotics and season.

Conclusions: Detection and density of S. pneumoniae in the upper airways do not correlate with CAP presence or severity. High RSV and HMPV loads were linked to severe CAP.

Background: Acinetobacter seifertii, a recently identified member of the Acinetobacter calcoaceticus-Acinetobacter baumannii (Acb) complex, has emerged as a cause of severe human infections. It is closely related to Acinetobacter nosocomialis, a major pathogen of the Acb complex. Here, we aimed to explore the clinical and molecular differences between these two species.

Methods: This retrospective study enrolled 83 adults with A. seifertii bacteremia and 402 adults with A. nosocomialis bacteremia from four medical centers over a 9-year period. Species identification was confirmed using matrix-assisted laser desorption ionization-time of flight mass spectrometry and rpoB sequencing. Clinical information, antimicrobial susceptibility, and carbapenem resistance determinants were analyzed.

Results: There were no significant differences in the underlying diseases or mortality between patients with A. seifertii and A. nosocomialis bacteremia. However, A. seifertii bacteremia was more frequently associated with intensive care unit (ICU) admission, recent ICU stay, central venous catheter use, ventilator use at bacteremia onset, and pneumonia as the primary infection source than A. nosocomialis bacteremia. A. seifertii exhibited significantly lower susceptibility to colistin, amikacin, gentamicin, ceftazidime, and cefepime than A. nosocomialis. Carbapenem resistance was primarily mediated by ISAba1-bla_OXA-51-like in A. seifertii and IS1006-ΔISAba3-bla_OXA-58-like in A. nosocomialis.

Conclusion: A. seifertii and A. nosocomialis exhibit distinct antimicrobial susceptibility profiles and carbapenem resistance mechanisms but share similar mortality rates. The ability of both species to act as reservoirs of carbapenem resistance highlights the importance of accurate identification, antimicrobial stewardship, and infection control strategies to mitigate the spread of resistant strains.

Sexually transmitted infections (STIs) continue to pose major public health challenges globally, with millions of new cases reported annually. The asymptomatic characteristic of many STIs makes accurate and cost-effective diagnostic methods essential for screening and diagnosis. This paper evaluates the utility of enzyme-linked immunosorbent assays (ELISAs) in diagnoses of HIV, HPV, HSV, HBV, HCV, Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis and Treponema pallidum. Compared to nucleic acid amplification tests (NAATs), ELISAs have advantages that include minimal training requirements, lower costs, and suitability for community screening programs. Despite their practical advantages, conventional ELISAs face key performance limitations, cross-reactivity, lower sensitivity, and delayed detection, that have restricted their broader adoption, reducing the potential for ELISAs to become a standard STI detection method. Currently, advancements in ultrasensitive and digital ELISA technologies have greatly improved their accuracy and may improve the dilemma. This review describes current ELISA methodologies, efficacies, and limitations as observed in and reported for clinical applications and offers a comprehensive perspective on essential STI diagnostic improvements, motivated by the belief that ELISA techniques can significantly contribute to the early detection, treatment, and containment of STIs.

Background: Adherence to antiretroviral therapy (ART) is critical for successful viral suppression in people living with HIV (PLHIV). The comparative effectiveness of two-drug regimens (2DRs) versus three-drug regimens (3DRs)-particularly in Asian populations-is an underexplored topic.

Methods: This retrospective cross-sectional study was conducted at two hospitals in Taiwan between November 2023 and January 2025. Adherence was measured in terms of the proportion of days covered (PDC) over 365 days. Logistic regression analyses were used to evaluate the effectiveness of viral suppression and factors associated with regimen selection.

Results: Of the 628 PLHIV included, most were men, aged between 30 and 50 years, identified as lesbian, gay, bisexual, or transgender, and had received their diagnosis of HIV >5 years prior to this study. Among the participants receiving 3DRs (81.37 %), 3.72 % had viral loads exceeding 200 copies/mL. Regarding those receiving 2DRs (18.63 %), 2.56 % exhibited similar viral loads (p = 0.781). Multivariable analysis indicated that PDC ≥75 % was strongly associated with viral suppression (adjusted odds ratio [aOR] = 45.80, p < 0.0001), with no significant difference in viral suppression rates between regimens. The participants receiving 3DRs were less likely to have >75 % adherence (aOR = 0.18, p = 0.018) and to have a long HIV history (>5 years; aOR = 0.22, p = 0.041).

Conclusion: Adherence, not regimen type, is the key factor affecting viral suppression. Nevertheless, the findings should be cautiously interpreted because of potential bias and small subgroup sizes. Further prospective studies should evaluate the comparative efficacy of these regimens.