New Microbiologica最新文献

Antibiotic-resistant S. aureus infections can be life-threatening. Linezolid is known to hinder S. aureus biofilm formation, but the underlying molecular mechanism remains unclear. Molecular docking revealed that linezolid can bind to icaA, and this was confirmed by thermal drift assays. Linezolid demonstrated a dose-dependent inhibition of icaA enzyme activity. Mutating Trp267, a key residue identified through molecular docking, significantly decreased linezolid binding and inhibitory effects on mutant icaA activity. However, the mutant icaA Trp267Ala showed only slight activity reduction compared to icaA. Linezolid had minimal impact on icaB's thermal stability and activity. The 50S ribosomal L3ΔSer145 mutant S. aureus exhibited similar growth and biofilm formation to the wild-type strain. Linezolid effectively suppressed the growth and biofilm formation of wildtype S. aureus. Although linezolid lost its ability to inhibit the growth of the mutant strain, it still effectively hindered its biofilm formation. Linezolid exhibited weaker attenuation of sepsis-induced lung injury caused by 50S ribosomal L3ΔSer145 mutant S. aureus compared to wild-type S. aureus. These findings indicate that linezolid hampers S. aureus biofilm formation by directly inhibiting icaA activity, independently of its impact on bacterial growth.

To achieve the World Health Organization goal of hepatitis C virus (HCV) eradication, barriers to treatment should be investigated and overcome. The aim of this study was to identify those barriers and describe the strategies adopted to achieve HCV micro-elimination in a cohort of coinfected people living with HIV (PLWH-HCV). Adult PLWH-HCV followed at our hospital with detectable serum HCV-RNA in 2018 were enrolled. After a three-year follow-up, barriers to HCV treatment were investigated and strategies to overcome them were described. Of 492 PLWH-HCV seen in 2018, 29 (5.9%) had detectable serum HCV-RNA. Eight out of 29 (27.6%) were excluded because they were already under treatment, while 2 others were excluded because they moved to other outpatient clinics. Among the remaining 19 study participants, the most common barriers to treatment were poor adherence to therapies and follow-up visits (n=9, 47%), recent HCV diagnosis awaiting proper staging (n=3, 16%) and treatment hesitancy (n=2, 10%). During the following three years, direct-acting antivirals (DAAs) treatment was completed in 11/19 (58%) cases, with achievement of sustained virological response in 100% of cases. For the remaining cases, 2/19 (10.5%) were lost to follow-up, 2/19 (10.5%) died before treatment initiation and 4/19 (21.0%) are still awaiting treatment. Despite 3 years of effort, HCV micro-elimination has not been achieved at our center. We observed that poor adherence and treatment hesitancy were the main barriers to treatment. Strategies addressing these issues need to be implemented.

Hepatitis C virus (HCV) infection is an important public health problem with potential risk for Turkey. In order to contribute to the epidemiological data, we aimed to investigate the changes in seroprevalence, viremia rates, and genotypes in the last five years in HCV patients in the southern region of Turkey, which has received heavy migration in recent years, according to demographic criteria. In our study, we analyzed the results retrospectively with demographic data. Conducted at a single center, the study involved 259,875 anti-HCV antibody tests administered between January 2018 and July 2022. The study revealed a prevalence of 0.5% for HCV antibody positivity and a viremia prevalence of 0.1%. Among Turkish nationals, the most common genotypes were GT1 (65.1%), while foreign nationals, mainly of Syrian and Ukrainian origin, showed GT4 (52.3%) as the predominant genotype (p<0.001 for both). Although GT2 (7.4% vs. 4.5%) and GT3 (23.3% vs. 13.6%) were relatively higher in Turkish nationals compared to foreign nationals, the difference was not statistically significant (p=0.750 and p=0.154, respectively). This highlights the importance of continuous monitoring and public health efforts to address the potential impact of these demographic shifts on HCV epidemiology in the region.

The pillar of treatment success, defined as viral suppression and immune restoration, should be integrated into a modern vision of therapeutic success with pharmacological attributes of ART, such as potency, forgiveness, and genetic barrier of single drugs and regimens, as well as their longterm tolerability and safety. Moreover, the longterm success of lifelong treatment cannot be separated from the opinions and preferences of PLWH. Regimen Optimization in the setting of HIV suppression may reduce pill burden, and/or dosing frequency, enhance tolerability and/or decrease toxicity, prevent or mitigate DDIs, eliminate food/fluid requirements, relieve pill fatigue, decrease stigma or concerns associated with taking oral med, allow pregnancy, reduce costs (DHHS 2023). Regimen Optimization should be tailored by a person-centered perspective, based on the individual therapeutic history, past toxicities and comorbidities. The treatment strategy should be based on the perceived tolerability and quality of life, considering the preferences of people on treatment along with the virological and pharmacological factors. The health care system should facilitate universal and rapid access to personalized, robust, and effective therapies. The BIC/FTC/TAF association ensures all these characteristics and therefore represents a valid strategy for optimizing treatment in PLWH virologically suppressed.

In this study the antibiotic susceptibility pattern and bla genes were characterized in Klebsiella pneumoniae clinical isolates that fingerprinted by rep-PCR and PFGE methods at Kurdistan Province, Iran. A total of 70 K. pneumoniae were isolated from clinical samples to detect the antimicrobial susceptibility, carbapenemase and MBL-producing isolates. The PCR assay was used to identify the bla genes. Isolates were typed by PFGE and Rep-PCR methods. The highest and lowest rates of resistance were observed in cefotaxime (67.1%) and imipenem (8.6%), respectively. The rate of blaNDM-1 and blaOXA-48 genes were 1 (1.4%) and 14 (20%) isolates, respectively. All were classified in 27 clusters by rep-PCR and 39 PFGE types. The low frequency of carbapenemase and MBL genes in this study are epidemiologically important.

The purpose of the current study was to describe the prevalence of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) in northeastern Bulgaria. From January 2019 to December 2021, we tested 1493 samples for anti-HSV-1 IgG and 817 samples for anti-HSV-2 IgG antibodies in the Virology Laboratory, "St. Marina" University Hospital, Varna, Bulgaria. HSV-1 was considerably more widespread, with an overall seroprevalence of 73.3% (95% CI: 71.0-75.5%), than HSV-2 infection, which showed a seropositive rate of 10.0% (95% CI: 8.1-12.4%). Age was the most significant risk factor for both infections, while gender had no role in herpes simplex seropositivity.

Food safety is the primary concern of the food industry. The aim of the current research is to study the antimicrobial effects of cell-free supernatant of Lactobacillus pentosus against Bacillus cereus and Klebsiella pneumoniae. B. cereus and K. pneumoniae were isolated from infant formula milk product and meat sample, respectively. Their identification was performed through morphological characterization and biochemical testing. Molecular identification of K. pneumoniae was based on 16s ribotyping. A previously isolated and reported strain of L. pentosus was used for the isolation of CFS (Cellfree supernatants). Antimicrobial activity was studied through agar well diffusion assay. Inhibitory activity was recorded by measuring the zone of inhibition. CFS activity was evaluated for temperature and pH. The antimicrobial activity of CFS of L. pentosus produced at different temperatures and pH was investigated against B. cereus and K. pneumoniae. A clear zone of inhibition was observed against B. cereus while no ZOI was formed against K. pneumoniae. K. pneumoniae was found resistant to the CFS. Crude bacteriocin exhibited heat stability for a temperature of 121°C for 30 minutes and pH range of 3-7. The current study concluded that bacteriocin produced from L. pentosus can be used for the control of B. cereus. Its heat and pH stability allows its potential therapeutic use in the food industry as a food preservative and to control food poisoning cases due to B. cereus. K. pneumoniaeis was found resistant to the isolated bacteriocin, and therefore L. pentosus cannot be used for control against K. pneumoniae.

The study's objective was to assess whether the performance of the DIAGNOVITAL SARS-CoV-2 Mutation Detection Assays is affected by Omicron mutations. In silico evaluation of 67,717 Variant of Concern, Variant of Interest sequences and 6,612 sequences of the Omicron variants involving BA1., BA2., BA3 sub-lineages downloaded from the GISAID database by 17 December 2021, were performed. The sequences were aligned according to the reference genome MN908947.3 using MAFFT multiple sequence alignment software version 7. Our findings showed that among 6,612 Omicron, 41 Spike gene mutations with a frequency of ≥70% were identified. Some of the Omicron mutations (R408S, N440K, G446S, Q493S, Q498R) could affect the diagnostic performance of K417N, L452R, and E484K assays against the Omicron sub-lineages. However, L452R and K417N mutation tests allow differentiation of the Delta and Omicron variants mutation profile. The COVID-19 pandemic lasted longer than expected, and the rapid modification of diagnostic kits seems necessary to combat the pandemic.

The aim of the TWODAY Study was to investigate the frequency of early treatment change after rapid start of a tailored ART regimen (a 2-drug regimen - 2DR, when clinically feasible or a 3-drug regimen - 3DR, otherwise). TWODAY was an open-label, prospective, proof-of-concept, single center study. ART-naïve patients started their first-line regimen within a few days from the first laboratory testing with a 2DR of dolutegravir (DTG) and lamivudine (3TC) if CD4+ count >200 cells/mL, HIVRNA <500,000 copies/mL, no transmitted drug resistance to DTG or 3TC and HBsAg undetectable; otherwise, ART was started with a 3DR. The primary endpoint was the proportion of patients who needed to change ART within four week from start, for any reason. Thirty-two patients were enrolled; 19 (59.3%) were deemed eligible for a 2DR. Median time from laboratory testing to ART start was 5 days (5; 5). No regimen modification occurred within one month. In conclusion, no regimen modification was needed within the first month of treatment. Starting a 2DR within a few days after HIV diagnosis was feasible, relying upon complete results of the needed laboratory tests (including resistance testing). A 2DR can be safely proposed provided full laboratory tests are readily available.

Ceftolozane (CTLZ) is a novel cephalosporin antibiotic that exhibits broad-spectrum activity against gram-negative pathogens, including Pseudomonas aeruginosa, especially when combined with tazobactam (TAZ). We examined the minimum inhibitory concentration (MIC) of CTLZ/TAZ for 21 multidrug-resistant P. aeruginosa (MDRP) and eight carbapenem-resistant P. aeruginosa (CRPA) strains isolated at Okayama University Hospital, Japan. Consequently, 81% (17/21) of the MDRP strains and 25% (2/8) of the CRPA strains were resistant to CTLZ/TAZ (MIC >8 μg/mL). All 18 blaIMP-positive strains showed resistance to CTLZ/TAZ, whereas the drug retained in vitro susceptibility in 54.5% (6/11 strains) of blaIMP-negative strains.