The vaginal microbiome composition during pregnancy in a region compromising different ethnic origins.

BACKGROUND: The vaginal microbiota plays a significant role in pregnancy outcomes and newborn health. Indeed, the composition and diversity of the vaginal microbiota can vary among different ethnic groups. Our study aimed to investigate the composition of the vaginal microbiome throughout the three trimesters of pregnancy and to identify any potential variations or patterns in the Turkish population compromising mixed ethnicities. METHOD: We conducted a longitudinal study to characterize the vaginal microbiota of pregnant women. The study included a total of 25 participants, and the samples were collected at each trimester: 11-13 weeks, 20-24 weeks and 28-34 weeks gestation. RESULTS: Lactobacillus species were consistently found to be dominant in the vaginal microbiota throughout all trimesters of pregnancy. Among Lactobacillus species, L. crispatus had the highest abundance in all trimesters (40.6%, 40.8% and 44.4%, respectively). L. iners was the second most prevalent species (28.5%, 31% and 25.04, respectively). Our findings reveal that the dominant composition of the vaginal microbiota aligns with the CST-type I, commonly observed in the European population. CONCLUSIONS: This suggests that there are shared mechanisms influencing the microbial communities in the vagina, which are likely influenced by factors such as genetics, lifestyle, and cultural behaviors rather than ethnicity alone. The complex interplay of these factors contributes to the establishment and maintenance of the vaginal microbiota during pregnancy. Understanding the underlying mechanisms and their impact on vaginal health across diverse populations is essential for improving pregnancy outcomes. The study was approved by the Koc University Ethical Committee (no:2019.093.IRB2.030) and registered at the clinical trials.

Selective antibacterial and antibiofilm activity of chlorinated hemicyanine against gram-positive bacteria.

Antibiotic-free therapies are highly needed due to the limited success of conventional approaches especially against biofilm related infections. In this direction, antimicrobial phototherapy, either in the form of antimicrobial photothermal therapy (aPTT) or antimicrobial photodynamic therapy (aPDT), have appeared to be highly promising candidates in recent years. These are local and promising approaches for antibiotic resistant bacterial infections and biofilms. Organic small photosensitizers (PSs) are extensively preferred in antimicrobial phototherapy applications as they offer a great opportunity to combine therapeutic action (aPTT, aPDT or both) with fluorescence imaging on a single molecule. In this study, the bactericidal effect of cationic chlorinated hemicyanine (Cl-Hem)-based type I PS, which can function as a dual aPDT/aPTT agent, was investigated on both planktonic cells and biofilms of different gram-positive (E. faecalis and S. epidermidis) and gram-negative bacteria (P. aeruginosa and K. pneumoniae) with and without 640 nm laser irradiation. Cl-Hem was shown to induce a selective phototheranostic activity against gram-positive bacteria (E. faecalis and S. epidermidis). Cl-Hem exhibited both dose and laser irradiation time dependent bactericidal effect on planktonic and biofilms of S. epidermidis. These results clearly showed that highly potent Cl-Hem can treat resistant microbial infections, while allowing fluorescence detection at the same time. High biofilm reduction observed with combined aPDT/aPTT action of Cl-Hem together with its non-cytotoxic nature points out that Cl-Hem is a promising PS for antibacterial and antibiofilm treatments.

Discrepancy between IDSA and ESGBOR in Lyme disease: Individual participant meta-analysis in Türkiye.

BACKGROUND: The evidence on the prevalence of Lyme borreliosis (LB) is limited, but there is a suspicion of overdiagnosis of LB in recent years. We reviewed the LB diagnosis and treatment-related data in Türkiye, based on the Infectious Diseases Society of America (IDSA) 2020 and European Society of Clinical Microbiology and Infectious Diseases Study Group for Lyme Borreliosis (ESGBOR) 2018 guidelines. By detecting the disagreements between these two, we outlined the areas to be improved for future guidelines. METHODS: We performed a literature search according to the PRISMA guidelines in PubMed, Ovid-Medline, Web of Science, Turkish Medline, Scopus, CINAHL, ULAKBIM TR Index, Google Scholar and Cochrane Library databases. We included the published cases in a database and evaluated according to IDSA and ESGBOR guidelines. We outlined the reasons for misdiagnoses and inappropriate uses of antibiotics. RESULTS: We included 42 relevant studies with 84 LB cases reported from Türkiye between 1990 and December 2022. Among 84 cases, the most common clinical findings were nervous system findings (n = 37, 44.0%), erythema migrans (n = 29, 34.5%) and ophthalmologic findings (n = 15, 17.9%). The IDSA 2020 and ESGBOR 2018 guidelines agreed on the diagnosis of 71 (84.5%) cases; there was an agreement that 31 cases (36.9%) were misdiagnosed and 40 cases (47.6%) were correctly diagnosed, and there was disagreement for 13 cases (15.5%). Serum immunoglobulin M (IgM), IgG measurements by ELISA and western blot were widely performed, and they were effective in definitive diagnosis merely when used according to guidelines. Inappropriate use of antibiotics was detected in 42 (50.0%) of cases which were classified in the following categories: incorrect LB diagnosis, inappropriate choice of antibiotic, inappropriate route of drug administration and prolonged antibiotic treatment. CONCLUSION: Overdiagnosis and non-adherence to guidelines is a common problem. The discordance between seroprevalence and clinical studies necessitates a consensus over the best clinical approach.

Erythrocyte-Leveraged Oncolytic Virotherapy (ELeOVt): Oncolytic Virus Assembly on Erythrocyte Surface to Combat Pulmonary Metastasis and Alleviate Side Effects.

Despite being a new promising tool for cancer therapy, intravenous delivery of oncolytic viruses (OVs) is greatly limited by poor tumor targeting, rapid clearance in the blood, severe organ toxicity, and cytokine release syndrome. Herein, a simple and efficient strategy of erythrocyte-leveraged oncolytic virotherapy (ELeOVt) is reported, which for the first time assembled OVs on the surface of erythrocytes with up to near 100% efficiency and allowed targeted delivery of OVs to the lung after intravenous injection to achieve excellent treatment of pulmonary metastases while greatly improving the biocompatibility of OVs as a drug. Polyethyleneimine (PEI) as a bridge to assemble OVs on erythrocytes also played an important role in promoting the transfection of OVs. It is found that ELeOVt approach significantly prolonged the circulation time of OVs and increased the OVs distribution in the lung by more than tenfold, thereby significantly improving the treatment of lung metastases while reducing organ and systemic toxicity. Taken together, these findings suggest that the ELeOVt provides a biocompatible, efficient, and widely available approach to empower OVs to combat lung metastasis.

Does Emerging Carbapenem Resistance in Acinetobacter baumannii Increase the Case Fatality Rate? Systematic Review and Meta-Analysis.

BACKGROUND: In the era of rising carbapenem resistance, we aimed to investigate the change in mortality rate and positivity of carbapenemase genes in Acinetobacter baumannii. METHODS: Preferred Reporting Items for Systematic Review (PRISMA) guidelines were adopted in this systematic review. Our literature search included the Cochrane Library, Pubmed, Scopus, Web of Science, Medline, Tubitak TR Dizin, and Harman databases for studies dating back from 2003 to 2023 reporting bloodstream A. baumannii infections in Türkiye. A simple linear regression model was used to determine the association between resistance, mortality, and time. RESULTS: A total of 1717 studies were identified through a literature search, and 21 articles were selected based on the availability of the data regarding mortality and resistance rate (four articles) or the molecular epidemiology of carbapenem-resistant A. baumannii (17 articles) in Türkiye. From 2007 to 2018, the carbapenem resistance rate increased (p = 0.025). The OXA-23 and OXA-58 positivities were inversely correlated (p = 0.025). CONCLUSIONS: Despite the emergence of carbapenem resistance, mortality did not increase in parallel, which may be due to improved medical advancements or the fitness cost of bacteria upon prolonged antimicrobial exposure. Therefore, we suggest further global research with the foresight to assess clonal relatedness that might affect the carbapenem resistance rate.

LPS adsorption and inflammation alleviation by polymyxin B-modified liposomes for atherosclerosis treatment.

Chronic inflammation is critical in the onset and progression of atherosclerosis (AS). The lipopolysaccharide (LPS) level in the circulation system is elevated in AS patients and animal models, which is correlated with the severity of AS. Inspired by the underlying mechanism that LPS could drive the polarization of macrophages toward the M1 phenotype, aggravate inflammation, and ultimately contribute to the exacerbation of AS, LPS in the circulation system was supposed to be the therapeutic target for AS treatment. In the present study, polymyxin (PMB) covalently conjugated to PEGylated liposomes (PLPs) were formulated to adsorb LPS through specific interactions between PMB and LPS. In vitro, the experiments demonstrated that PLPs could adsorb LPS, reduce the polarization of macrophages to M1 phenotype and inhibit the formation of foam cells. In vivo, the study revealed that PLPs treatment reduced the serum levels of LPS and pro-inflammatory cytokines, decreased the proportion of M1-type macrophages in AS plaque, stabilized AS plaque, and downsized the plaque burdens in arteries, which eventually attenuated the progression of AS. Our study highlighted LPS in the circulation system as the therapeutic target for AS and provided an alternative strategy for AS treatment.

Fimbria targeting superparamagnetic iron oxide nanoparticles enhance the antimicrobial and antibiofilm activity of ciprofloxacin against quinolone-resistant E. coli.

High quinolone resistance of Escherichia coli limits the therapy options for urinary tract infection (UTI). In response to the urgent need for efficient treatment of multidrug-resistant infections, we designed a fimbriae targeting superparamagnetic iron oxide nanoparticle (SPION) delivering ciprofloxacin to ciprofloxacin-resistant E. coli. Bovine serum albumin (BSA) conjugated poly(acrylic acid) (PAA) coated SPIONs (BSA@PAA@SPION) were developed for encapsulation of ciprofloxacin and the nanoparticles were tagged with 4-aminophenyl-α-D-mannopyrannoside (mannoside, Man) to target E. coli fimbriae. Ciprofloxacin-loaded mannoside tagged nanoparticles (Cip-Man-BSA@PAA@SPION) provided high antibacterial activity (97.1 and 97.5%, respectively) with a dose of 32 µg/mL ciprofloxacin against two ciprofloxacin-resistant E. coli isolates. Furthermore, a strong biofilm inhibition (86.9% and 98.5%, respectively) was achieved in the isolates at a dose 16 and 8 times lower than the minimum biofilm eradication concentration (MBEC) of ciprofloxacin. Weaker growth inhibition was observed with untargeted nanoparticles, Cip-BSA@PAA@SPIONs, confirming that targeting E. coli fimbria with mannoside-tagged nanoparticles increases the ciprofloxacin efficiency to treat ciprofloxacin-resistant E. coli. Enhanced killing activity against ciprofloxacin-resistant E. coli planktonic cells and strong growth inhibition of their biofilms suggest that Cip-Man-BSA@PAA@SPION system might be an alternative and/or complementary therapeutic option for the treatment of quinolone-resistant E. coli infections.

Higher rates of cefiderocol resistance among NDM producing Klebsiella bloodstream isolates applying EUCAST over CLSI breakpoints.

BACKGROUND: Cefiderocol is generally active against carbapenem-resistant Klebsiella spp. (CRK) with higher MICs against metallo-beta-lactamase producers. There is a variation in cefiderocol interpretive criteria determined by EUCAST and CLSI. Our objective was to test CRK isolates against cefiderocol and compare cefiderocol susceptibilities using EUCAST and CLSI interpretive criteria. METHODS: A unique collection (n = 254) of mainly OXA-48-like- or NDM-producing CRK bloodstream isolates were tested against cefiderocol with disc diffusion (Mast Diagnostics, UK). Beta-lactam resistance genes and multilocus sequence types were identified using bioinformatics analyses on complete bacterial genomes. RESULTS: Median cefiderocol inhibition zone diameter was 24 mm (interquartile range [IQR] 24-26 mm) for all isolates and 18 mm (IQR 15-21 mm) for NDM producers. We observed significant variability between cefiderocol susceptibilities using EUCAST and CLSI breakpoints, such that 26% and 2% of all isolates, and 81% and 12% of the NDM producers were resistant to cefiderocol using EUCAST and CLSI interpretive criteria, respectively. CONCLUSIONS: Cefiderocol resistance rates among NDM producers are high using EUCAST criteria. Breakpoint variability may have significant implications on patient outcomes. Until more clinical outcome data are available, we suggest using EUCAST interpretive criteria for cefiderocol susceptibility testing.

BNT162b2 or CoronaVac as the Third Dose against Omicron: Neutralizing Antibody Responses among Transplant Recipients Who Had Received Two Doses of CoronaVac.

We evaluated neutralizing antibodies against the Omicron variant and Anti-Spike IgG response in solid organ (SOT) or hematopoietic stem cell (HSTC) recipients after a third dose of BNT162b2 (BNT) or CoronaVac (CV) following two doses of CV. In total, 95 participants underwent SOT (n = 62; 44 liver, 18 kidney) or HSCT (n = 27; 5 allogeneic, 22 autologous) were included from five centers in Turkey. The median time between third doses and serum sampling was 154 days (range between 15 to 381). The vaccine-induced antibody responses of both neutralizing antibodies and Anti-Spike IgGs were assessed by plaque neutralizing assay and immunoassay, respectively. Neutralizing antibody and Anti-Spike IgG levels were significantly higher in transplant patients receiving BNT compared to those receiving CV (Geometric mean (GMT):26.76 vs. 10.89; p = 0.03 and 2116 Au/mL vs. 172.1 Au/mL; p < 0.001). Solid organ transplantation recipients, particularly liver transplant recipients, showed lower antibody levels than HSCT recipients. Thus, among HSCT recipients, the GMT after BNT was 91.29 and it was 15.81 in the SOT group (p < 0.001). In SOT, antibody levels after BNT in kidney transplantation recipients were significantly higher than those in liver transplantation recipients (GMT: 48.32 vs. 11.72) (p < 0.001). Moreover, the neutralizing antibody levels after CV were very low (GMT: 10.81) in kidney transplantation recipients and below the detection limit (<10) in liver transplant recipients. This study highlights the superiority of BNT responses against Omicron as a third dose among transplant recipients after two doses of CV. The lack of neutralizing antibodies against Omicron after CV in liver transplant recipients should be taken into consideration, particularly in countries where inactivated vaccines are available in addition to mRNA vaccines.

The challenges in the monitoring of infectious diseases after the earthquake in Türkiye in 2023.

After the devastating earthquake in Türkiye and Syria in February, 2023, the long-term failure to meet the need for shelter, unfavourable living conditions in tent settlements, poor access to clean drinking water, water suitable for personal hygiene, and sanitary facilities, as well as interruptions in provision of primary health-care services, have emerged as the most important risk factors contributing to the spread of infectious diseases. 3 months after the earthquake, most of these problems persist in Türkiye. Data on the control of infectious diseases are scarce according to the reports prepared by medical specialist associations based on observations of health-care providers working in the region and statements made by the local health authorities. According to these unsystematised data, and considering the conditions in the region, faecal-oral transmissible gastrointestinal infections, as well as respiratory and vector-borne infections, are the main challenges. Vaccine-preventable diseases, such as measles, varicella, meningitis, and polio can be spread in temporary shelters due to interrupted vaccine services and crowded living conditions. In addition to controlling risk factors for infectious diseases, sharing data on the status and control of infectious diseases in the region with the community, health-care providers, and relevant expert groups should be a priority to improve the understanding of the effects of interventions and prepare for possible infectious disease outbreaks.

Virus-Protein Corona Replacement Strategy to Improve the Antitumor Efficacy of Intravenously Injected Oncolytic Adenovirus.

Intravenous administration of oncolytic adenoviruses (OVs) is a hopeful tumor therapeutic modality. However, the sharp clearance of OVs by the immune system dampens its effectiveness. Many studies have attempted to extend the circulation of intravenously administered OVs, almost all by preventing OVs from binding to neutralizing antibodies and complements in the blood, but the results have not been satisfactory. In contrast to previous conclusions, we found that the key to improving the circulation of OVs is to prevent the formation of the virus-protein corona rather than simply preventing the binding of neutralizing antibodies or complements to OVs. After identifying the key protein components of the virus-protein corona, we proposed a virus-protein corona replacement strategy, where an artificial virus-protein corona was formed on OVs to completely prevent the interaction of OVs with key virus-protein corona components in the plasma. It was found that this strategy dramatically prolonged the circulation time of OVs by over 30 fold and increased the distribution of OVs in tumors by over 10-fold, resulting in superior antitumor efficacy in primary and metastatic tumor models. Our finding provides a perspective on intravenous delivery of OVs, shifting the focus of future studies from preventing OV binding with neutralization antibodies and complements to preventing OVs from interacting with key virus-protein corona components in the plasma.

Update of European Society of Clinical Microbiology and Infectious Diseases coronavirus disease 2019 guidelines: diagnostic testing for severe acute respiratory syndrome coronavirus 2.

SCOPE: Since the onset of COVID-19, several assays have been deployed for the diagnosis of SARS-CoV-2. The European Society of Clinical Microbiology and Infectious Diseases (ESCMID) published the first set of guidelines on SARS-CoV-2 in vitro diagnosis in February 2022. Because the COVID-19 landscape is rapidly evolving, the relevant ESCMID guidelines panel releases an update of the previously published recommendations on diagnostic testing for SARS-CoV-2. This update aims to delineate the best diagnostic approach for SARS-CoV-2 in different populations based on current evidence. METHODS: An ESCMID COVID-19 guidelines task force was established by the ESCMID Executive Committee. A small group was established, half appointed by the chair, and the remaining selected with an open call. The panel met virtually once a week. For all decisions, a simple majority vote was used. A list of clinical questions using the population, intervention, comparison, and outcome (PICO) format was developed at the beginning of the process. For each PICO, 2 panel members performed a literature search focusing on systematic reviews with a third panellist involved in case of inconsistent results. The panel reassessed the PICOs previously defined as priority in the first set of guidelines and decided to address 49 PICO questions, because 6 of them were discarded as outdated/non-clinically relevant. The 'Grading of Recommendations Assessment, Development and Evaluation (GRADE)-adoption, adaptation, and de novo development of recommendations (ADOLOPMENT)' evidence-to-decision framework was used to produce the guidelines. QUESTIONS ADDRESSED BY THE GUIDELINES AND RECOMMENDATIONS: After literature search, we updated 16 PICO questions; these PICOs address the use of antigen-based assays among symptomatic and asymptomatic patients with different ages, COVID-19 severity status or risk for severe COVID-19, time since the onset of symptoms/contact with an infectious case, and finally, types of biomaterials used.

Clinical evaluation of DIAGNOVIR SARS-CoV-2 ultra-rapid antigen test performance compared to PCR-based testing.

Coronavirus Disease-19 (COVID-19) is a highly contagious infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The development of rapid antigen tests has contributed to easing the burden on healthcare and lifting restrictions by detecting infected individuals to help prevent further transmission of the virus. We developed a state-of-art rapid antigen testing system, named DIAGNOVIR, based on immune-fluorescence analysis, which can process and give the results in a minute. In our study, we assessed the performance of the DIAGNOVIR and compared the results with those of the qRT-PCR test. Our results demonstrated that the sensitivity and specificity of the DIAGNOVIR were 94% and 99.2%, respectively, with a 100% sensitivity and 96.97% specificity, among asymptomatic patients. In addition, DIAGNOVIR can detect SARS­CoV­2 with 100% sensitivity up to 5 days after symptom onset. We observed that the DIAGNOVIR Rapid Antigen Test's limit of detection (LoD) was not significantly affected by the SARS­CoV­2 variants including Wuhan, alpha (B1.1.7), beta (B.1.351), delta (B.1.617.2) and omicron (B.1.1.529) variants, and LoD was calculated as 8 × 102, 6.81 × 101.5, 3.2 × 101.5, 1 × 103, and 1 × 103.5 TCID50/mL, respectively. Our results indicated that DIAGNOVIR can detect all SARS-CoV-2 variants in just seconds with higher sensitivity and specificity lower testing costs and decreased turnover time.

Plasma proteomics identify potential severity biomarkers from COVID-19 associated network.

PURPOSE: Coronavirus disease 2019 (COVID-19) continues to threaten public health globally. Severe acute respiratory coronavirus type 2 (SARS-CoV-2) infection-dependent alterations in the host cell signaling network may unveil potential target proteins and pathways for therapeutic strategies. In this study, we aim to define early severity biomarkers and monitor altered pathways in the course of SARS-CoV-2 infection. EXPERIMENTAL DESIGN: We systematically analyzed plasma proteomes of COVID-19 patients from Turkey by using mass spectrometry. Different severity grades (moderate, severe, and critical) and periods of disease (early, inflammatory, and recovery) are monitored. Significant alterations in protein expressions are used to reconstruct the COVID-19 associated network that was further extended to connect viral and host proteins. RESULTS: Across all COVID-19 patients, 111 differentially expressed proteins were found, of which 28 proteins were unique to our study mainly enriching in immunoglobulin production. By monitoring different severity grades and periods of disease, CLEC3B, MST1, and ITIH2 were identified as potential early predictors of COVID-19 severity. Most importantly, we extended the COVID-19 associated network with viral proteins and showed the connectedness of viral proteins with human proteins. The most connected viral protein ORF8, which has a role in immune evasion, targets many host proteins tightly connected to the deregulated human plasma proteins. CONCLUSIONS AND CLINICAL RELEVANCE: Plasma proteomes from critical patients are intrinsically clustered in a distinct group than severe and moderate patients. Importantly, we did not recover any grouping based on the infection period, suggesting their distinct proteome even in the recovery phase. The new potential early severity markers can be further studied for their value in the clinics to monitor COVID-19 prognosis. Beyond the list of plasma proteins, our disease-associated network unravels altered pathways, and the possible therapeutic targets in SARS-CoV-2 infection by connecting human and viral proteins. Follow-up studies on the disease associated network that we propose here will be useful to determine molecular details of viral perturbation and to address how the infection affects human physiology.

Duration of infectious shedding of SARS-CoV-2 Omicron variant and its relation with symptoms.

OBJECTIVES: SARS-CoV-2 infections with Omicron variants have a high capability of human-to-human transmission. Nevertheless, the duration of isolation for mild cases was shortened to 5 to 7 days. We aimed to detect the duration of viral shedding among healthcare workers (HCWs) with Omicron by using viral culture. METHODS: We prospectively included newly diagnosed nonsevere, symptomatic SARS-CoV-2 positive HCWs. Nasopharyngeal swab samples were obtained consecutively on days 5, 7,10, and 14 of onset of symptoms. The samples were examined by nucleic acid amplification test and viral culture. RESULTS: In total, 55 non-severe patients with SARS-CoV-2 Omicron variant were included. The mean age of the population was 34 years (range, 23 to 54) and 78% (43/55) were female. The PCR positivity rate on days 5, 7, 10, and 14 was 96.4% (53/55), 87.3% (48/55), 74.545% (41/55), and 41.8% (23/55) consecutively, whereas the viral culture positivity rates were 83% (44/53), 52% (26/50), 13.5% (7/52), and 8% (4/50). Among the patients who became symptom-free, the viral culture positivity rates were 100% (4/4), 58% (7/12), 11% (3/27), and 5% (2/41). DISCUSSION: We showed that among the SARS-CoV-2 Omicron variant infected patients, viral shedding continues for ≥10 days in 13.5% of all cases and 11% in symptom-free cases. The decision for cessation of isolation according to the presence of symptoms could be reconsidered until further studies disapprove of our results. Meanwhile, the infected HCWs who give care to high-risk patients for severe COVID-19 might extend their isolations ≤10 days after the onset of symptoms, regardless of their symptoms.

Alterations in vaginal microbiota among pregnant women with COVID-19.

The maintenance of vaginal microbiota is an important factor to achieve optimum pregnancy outcomes. The study aims to describe the alterations in the composition of vaginal microbiota in pregnant women with coronavirus disease 2019 (COVID-19). This was a prospective case-control study. Vaginal swabs were collected from uninfected pregnant women (n = 28) and pregnant women with COVID-19 (n = 19) during the active phase of infection and within a month after recovering from infection. The vaginal microbiota on the swabs was examined by 16S rRNA gene sequencing. Shannon index indicates that alpha diversity is significantly higher in women with COVID-19 (p = 0.012). There was a significant decrease in Firmicutes (p = 0.014) with an increase in Bacteroidota (p = 0.018) phyla and a decrease in Lactobacillus (p = 0.007) genus in women with COVID-19 than those of uninfected pregnant women. The relative abundance of L. crispatus, L. iners, L. gasseri, and L. jensenii were lower in the COVID-19 group than in uninfected pregnant women. In subgroup analysis, the amount of Ureaplasma spp. was higher in women with moderate/severe than those of asymptomatic/mild disease (p = 0.036). The study revealed that vaginal dysbiosis with low abundance of Lactobacillus species occurred in pregnant women infected with severe acute respiratory syndrome coronavirus-2. These findings may lead to new studies to elucidate the risk of pregnancy adverse outcomes related to COVID-19.

B Cell Subtypes in Individuals Received mRNA or Inactivated Vaccine Boosters After Fully Vaccinated with CoronaVac: A Longitudinal Study.

In this study, we aimed to investigate the changes in the B cell subpopulations after homologous or heterologous COVID-19 boosters. Blood samples were collected after baseline (3-5 months after two doses of CoronaVac), 1 and 3 months after BNT162b2 (n=28 and n=6), and CoronaVac (n=7 and n=4) boosters. Peripheral blood mononuclear cells (PBMCs) were isolated and stained with B cell markers, the ratios of naïve (CD19+CD20+CD27-), memory (CD19+CD20+CD27+), memory B cells expressing IgG (CD19+CD20+CD27+IgG+), and effector memory B cells (CD19+CD20+CD27+CD38+) were identified with flow cytometry. Significantly higher expression of memory B cells was observed in one month with BNT162b2 (12.16% one month, 5.98% three months) and CoronaVac (14.18% one month, 9.00% three months) boosters. IgG expressing memory B cell expression was significantly higher with BNT162b2 than with CoronaVac booster in one month (22.70% and 13.95%, respectively). The ratio of effector B cells in the first month after CoronaVac booster (25.44%) was significantly higher than the BNT162b2 booster (9.90%, p =0.0263).

The association between Acinetobacter baumannii infections and the COVID-19 pandemic in an intensive care unit.

We aimed to describe the increased rate of Acinetobacter baumannii infections during the COVID-19 pandemic and define its significance within the last five years. This study was performed in a tertiary hospital with 280 beds and included all patients infected with A. baumannii in the intensive care unit between January 1, 2018, and June 30, 2022. A. baumannii-infected patients in the intensive care unit 27 months before the pandemic and 27 months during the pandemic were included. Pulsed-field gel electrophoresis was performed to assess clonal relatedness. The infection control measures were specified based on the findings and targeted elimination. In total, 5718 patients were admitted to the intensive care unit from January 1st, 2018, to June 30th, 2022. A. baumannii infection was detected in 81 patients. Compared to the pre-pandemic era, the rate of A. baumannii infection during the pandemic was 1.90 times higher (OR: 1.90, 95% CI: [1.197, 3.033]). Clonality assessment of multidrug-resistant A. baumannii samples revealed eight clusters with one main cluster comprising 14/27 isolates between 2021 and 2022. The case fatality rate of the pre-pandemic and pandemic era was not different statistically (83.33% vs. 81.48%, p = 0.835). Univariate analysis revealed the association of mechanical ventilation (p = 0.002) and bacterial growth in tracheal aspirate (p = 0.001) with fatality. During the COVID-19 pandemic, potential deficits in infection control measures may lead to persistent nosocomial outbreaks. In this study, the introduction of enhanced and customized infection control measures has resulted in the containment of an A. baumannii outbreak.