The role of bacterial genital infections in spontaneous preterm delivery: a case-control study

Background

Spontaneous preterm delivery is defined as the beginning of the birth process before the 37th week of pregnancy. The presence of microorganisms in the fetal membranes is accompanied by an increase in the production of prostaglandin, one of the important factors associated with the prevalence of preterm birth. The invasion of microorganisms leads to the production of protease, coagulase, and elastase, which directly stimulate the onset of childbirth. We investigated the role of genital infections in women with preterm birth.

Methods

The present case-control study was conducted in the west of Iran on 100 women with spontaneous preterm delivery (following 24 weeks of gestation and before 36 weeks and 6 days) as the case group and 100 women with normal delivery as controls. A questionnaire was applied to collect the data. Polymerase chain reaction and pathological examination of the placenta were performed.

Results

The average age in women with normal delivery (30.92 ± 5.10) in women with spontaneous preterm delivery (30.27 ± 4.93). The prevalence of Chlamydia trachomatis, Neisseria gonorrhea, Listeria monocytogenes, and Mycoplasma genitalium infections was zero in both groups. The highest prevalence of Gardnerella vaginalis was 19 (19%) in the case group and Ureaplasma parvum 15 (15%) in the control group. Also, Placental inflammation was zero in controls and 7(7%) in the patient group. There was a significant relationship between Gardnerella vaginalis bacteria and spontaneous preterm delivery.

Conclusion

The results of our study showed that except for Gardnerella vaginalis bacteria, there is no significant relationship between the above bacterial infections and spontaneous preterm birth. Moreover, despite the significant reduction in the prevalence of many sexually transmitted infections in this research, it is still suggested to increase the awareness of people, including pregnant women, about the ways it can be transmitted by gynecologists and health and treatment centers.

Pneumococcal Colonization in Children With Persistent Asthma: A Retrospective Cohort

BACKGROUND

Asthma is the most common chronic medical condition among children ≥5 years of age with invasive pneumococcal disease. How asthma or its management affects pneumococcal colonization is not fully understood. Our objective was to compare pneumococcal colonization rates between children with persistent asthma and children without asthma, and to characterize the pneumococcal serotype distribution.

METHODS

We used nasal mid-turbinate samples obtained per routine care from 5- to 18-year-old children with upper respiratory symptoms from November to April (respiratory seasons) of 2017 to 2018 and 2018 to 2019 in Kansas City, United States. Pneumococcal immunization status, prior antibiotic use and other clinical data were collected. Samples were tested for pneumococcal colonization by real-time polymerase chain reaction targeting lytA gene. Positive samples underwent multiplex serotype-specific polymerase chain reaction assays to determine the serotype.

RESULTS

Of 363 children (120 with persistent asthma and 243 without asthma), 87.6% were 5 to 10 years old, 50.1% were female and 74.1% received ≥3 doses of a pneumococcal conjugate vaccine. The pneumococcal colonization rate was lower in children with persistent asthma than in children without asthma (10% versus 18.9%, P = 0.03). The odds of colonization were lower in children with persistent asthma [OR 0.4 (95% confidence interval: 0.2-0.9)] after adjusting for demographic and clinical data. Pneumococcal serotype was confirmed in 77.6% of positive samples; 35.6% of those samples corresponded to PCV13 serotypes and 64.4% to non-PCV13 serotypes. The most common serotypes were 19F (15%), 3 (13%) and 6C/6D (11%).

CONCLUSIONS

Children with persistent asthma had lower rates of pneumococcal colonization than children without asthma when seeking care for respiratory symptoms.

The Immune System-A Double-Edged Sword for Adenovirus-Based Therapies

Pathogenic adenovirus (Ad) infections are widespread but typically mild and transient, except in the immunocompromised. As vectors for gene therapy, vaccine, and oncology applications, Ad-based platforms offer advantages, including ease of genetic manipulation, scale of production, and well-established safety profiles, making them attractive tools for therapeutic development. However, the immune system often poses a significant challenge that must be overcome for adenovirus-based therapies to be truly efficacious. Both pre-existing anti-Ad immunity in the population as well as the rapid development of an immune response against engineered adenoviral vectors can have detrimental effects on the downstream impact of an adenovirus-based therapeutic. This review focuses on the different challenges posed, including pre-existing natural immunity and anti-vector immunity induced by a therapeutic, in the context of innate and adaptive immune responses. We summarise different approaches developed with the aim of tackling these problems, as well as their outcomes and potential future applications.

Urinary dengue NS1 detection on Au-decorated ZnO nanowire platform

Biodetection for non-invasive diagnostics of fluids, especially urine, remains a challenge to scientists due to low target concentrations. And biological complexes of the detection target may contain contaminants that also interfere with any assay. Dengue non-structural 1 protein (Dengue NS1) is an important biomarker for dengue hemorrhagic fever and dengue shock syndrome. Here, we developed an Au-decorated nanowire platform and applied it with a sandwich fluorophore-linked immunosorbent well plate assay (FLISA) to detect Dengue NS1 in urine. For the platform, we fabricated zinc oxide (ZnO) nanowires to provide a high surface area and then coated them with gold nanoparticles (ZnO/Au nanowires) to simply modify the Dengue NS1 antibody and enhance the fluorescence intensity. Our platform employs a sandwich FLISA that exhibits high sensitivity, specifically detecting Dengue NS1 with a limit of detection (LOD) of 1.35 pg/mL. This LOD was 4500-fold lower than the LOD of a commercially available kit for Dengue NS1 enzyme-linked immunosorbent assay. We believe that our ZnO/Au nanowire platform has the potential to revolutionize the field of non-invasive diagnostics for dengue.

Bacteria of healthy periodontal tissues as candidates of probiotics: a systematic review

OBJECTIVES

The use of probiotics could promote the balance of the subgingival microbiota to contribute to periodontal health. This study aimed to identify the potential of bacteria commonly associated with healthy periodontal tissues as probiotic candidates.

MATERIAL AND METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using the PubMed, Scopus, Science Direct, ProQuest, and Ovid databases as well as the combination of Medical Subject Headings (MeSH) and non-MeSH terms. Based on the selection criteria, original studies published in English and identifying the microorganisms present in the periodontium of healthy individuals and patients with periodontitis using the high-throughput 16S ribosomal gene sequencing technique were included.

RESULTS

Out of 659 articles, 12 met the criteria for this review. These articles were published from 2012 to 2020 and mainly originated from the United States, China, and Spain. Most of these studies reported adequate criteria for selecting participants, using standardized clinical criteria, and compliance with quality based on the tools used. In periodontal healthy tissue were identified species like Actinomyces viscosus, Actinomyces naeslundii, Haemophilus parainfluenzae, Rothia dentocariosa, Streptococcus sanguinis, Streptococcus mitis, Streptococcus oralis, Streptococcus gordonii, Streptococcus intermedius, and Prevotella nigrescens which have recognized strains with a capacity to inhibit periodontopathogens.

CONCLUSIONS

S. sanguinis, S. oralis, S. mitis, and S. gordonii are among the bacterial species proposed as potential probiotics because some strains can inhibit periodontopathogens and have been reported as safe for humans.

Phylogenetic Tracing of Evolutionarily Conserved Zonula Occludens Toxin Reveals a "High Value" Vaccine Candidate Specific for Treating Multi-Strain Pseudomonas aeruginosa Infections

Extensively drug-resistant Pseudomonas aeruginosa infections are emerging as a significant threat associated with adverse patient outcomes. Due to this organism's inherent properties of developing antibiotic resistance, we sought to investigate alternative strategies such as identifying "high value" antigens for immunotherapy-based purposes. Through extensive database mining, we discovered that numerous Gram-negative bacterial (GNB) genomes, many of which are known multidrug-resistant (MDR) pathogens, including P. aeruginosa, horizontally acquired the evolutionarily conserved gene encoding Zonula occludens toxin (Zot) with a substantial degree of homology. The toxin's genomic footprint among so many different GNB stresses its evolutionary importance. By employing in silico techniques such as proteomic-based phylogenetic tracing, in conjunction with comparative structural modeling, we discovered a highly conserved intermembrane associated stretch of 70 amino acids shared among all the GNB strains analyzed. The characterization of our newly identified antigen reveals it to be a "high value" vaccine candidate specific for P. aeruginosa. This newly identified antigen harbors multiple non-overlapping B- and T-cell epitopes exhibiting very high binding affinities and can adopt identical tertiary structures among the least genetically homologous P. aeruginosa strains. Taken together, using proteomic-driven reverse vaccinology techniques, we identified multiple "high value" vaccine candidates capable of eliciting a polarized immune response against all the P. aeruginosa genetic variants tested.

Efficacy and Safety of Respiratory Syncytial Virus (RSV) Prefusion F Protein Vaccine (RSVPreF3 OA) in Older Adults Over 2 RSV Seasons

BACKGROUND

The adjuvanted RSV prefusion F protein-based vaccine (RSVPreF3 OA) was efficacious against RSV-related lower respiratory tract disease (RSV-LRTD) in ≥60-years-olds over 1 RSV season. We evaluated efficacy and safety of 1 RSVPreF3 OA dose and of 2 RSVPreF3 OA doses given 1 year apart against RSV-LRTD over 2 RSV seasons post-dose 1.

METHODS

In this phase 3, blinded trial, ≥60-year-olds were randomized (1:1) to receive RSVPreF3 OA or placebo pre-season 1. RSVPreF3 OA recipients were re-randomized (1:1) to receive a second RSVPreF3 OA dose (RSV_revaccination group) or placebo (RSV_1dose group) pre-season 2; participants who received placebo pre-season 1 received placebo pre-season 2 (placebo group). Efficacy of both vaccine regimens against RSV-LRTD was evaluated over 2 seasons combined (confirmatory secondary objective, success criterion: lower limits of 2-sided CIs around efficacy estimates >20%).

RESULTS

The efficacy analysis comprised 24 967 participants (RSV_1dose: 6227; RSV_revaccination: 6242; placebo: 12 498). Median efficacy follow-up was 17.8 months. Efficacy over 2 seasons of 1 RSVPreF3 OA dose was 67.2% (97.5% CI: 48.2-80.0%) against RSV-LRTD and 78.8% (95% CI: 52.6-92.0%) against severe RSV-LRTD. Efficacy over 2 seasons of a first dose followed by revaccination was 67.1% (97.5% CI: 48.1-80.0%) against RSV-LRTD and 78.8% (95% CI: 52.5-92.0%) against severe RSV-LRTD. Reactogenicity/safety of the revaccination dose were similar to dose 1.

CONCLUSIONS

One RSVPreF3 OA dose was efficacious against RSV-LRTD over 2 RSV seasons in ≥60-year-olds. Revaccination 1 year post-dose 1 was well tolerated but did not seem to provide additional efficacy benefit in the overall study population.

CLINICAL TRIALS REGISTRATION

ClinicalTrials.gov: NCT04886596.

Schlafen 11 triggers innate immune responses through its ribonuclease activity upon detection of single-stranded DNA

Nucleic acids are major structures detected by the innate immune system. Although intracellular single-stranded DNA (ssDNA) accumulates during pathogen infection or disease, it remains unclear whether and how intracellular ssDNA stimulates the innate immune system. Here, we report that intracellular ssDNA triggers cytokine expression and cell death in a CGT motif-dependent manner. We identified Schlafen 11 (SLFN11) as an ssDNA-activated RNase, which is essential for the innate immune responses induced by intracellular ssDNA and adeno-associated virus infection. We found that SLFN11 directly binds ssDNA containing CGT motifs through its carboxyl-terminal domain, translocates to the cytoplasm upon ssDNA recognition, and triggers innate immune responses through its amino-terminal ribonuclease activity that cleaves transfer RNA (tRNA). Mice deficient in Slfn9, a mouse homolog of SLFN11, exhibited resistance to CGT ssDNA-induced inflammation, acute hepatitis, and septic shock. This study identifies CGT ssDNA and SLFN11/9 as a class of immunostimulatory nucleic acids and pattern recognition receptors, respectively, and conceptually couples DNA immune sensing to controlled RNase activation and tRNA cleavage.

Development of a novel rodent model for dog heartworm microfilaremia using the severe-combined immunodeficiency mouse

Dirofilaria immitis is a mosquito-borne parasitic nematode that causes fatal heartworm disease in canids. The microfilariae are essential for research, including drug screening and mosquito-parasite interactions. However, no reliable methods for maintaining microfilaria long-term are currently available. Therefore, we used severe combined immunodeficiency (SCID) mice to develop a reliable method for maintaining D. immitis microfilaria. SCID mice were injected intravenously with microfilariae isolated from a D. immitis-infected dog. Microfilariae were detected in blood collected from the tail vein 218 days post-inoculation (dpi) and via cardiac puncture 296 dpi. Microfilariae maintained in and extracted from SCID mice showed infectivity and matured into third-stage larvae (L3s) in the vector mosquito Aedes aegypti. L3s can develop into the fourth stage larvae in vitro. Microfilariae from SCID mice respond normally to ivermectin in vitro. The microfilariae in SCID mice displayed periodicity in the peripheral circulation. The SCID mouse model aided in the separation of microfilariae from cryopreserved specimens. The use of SCID mice enabled the isolation and sustained cultivation of microfilariae from clinical samples. These findings highlight the usefulness of the SCID mouse model for studying D. immitis microfilaremia in canine heartworm research.

Comparison of Clinical Characteristics and Treatment Outcome Between Localized and Disseminated Nocardiosis in a Tertiary Hospital in China

Background

In China, due to the large population, infections caused by Nocardia may not be as rare. Unfortunately, there is still inadequate knowledge of the clinical impact caused by Nocardia. This study aimed to compare the clinical characteristics and treatment of localized and disseminated nocardiosis.

Methods

The clinical and microbiological data of patients diagnosed with nocardiosis in a tertiary hospital in Beijing from July 2011 to July 2021 were collected and retrospectively analyzed.

Results

Among the 54 nocardiosis cases, 34 cases were in the localized infection group, while 20 cases in the disseminated infection group. The proportion of patients with chronic structural lung disease was higher in the localized group (P=0.010). In contrast, patients with disseminated infections were more prone to receive long-term glucocorticoids and/or immunosuppressants (P=0.027). Pulmonary nodules were prominent features of imaging changes in patients with disseminated infections (P=0.027) whereas bronchial dilatation was more common in patients with localized infections (P=0.025). In addition, the disseminated group had longer average hospitalization days relative to the localized group (P=0.016), but there was no significant difference in mortality between them (P=0.942).

Conclusion

There were differences in the clinical profiles between patients with localized and disseminated nocardiosis in terms of clinical presentation, infection site, radiological features, treatment, and prognosis. These findings may provide references for the management and treatment of patients with nocardiosis.

Transforming microbial pigment into therapeutic revelation: extraction and characterization of pyocyanin from Pseudomonas aeruginosa and its therapeutic potential as an antibacterial and anticancer agent

BACKGROUND

The objectives of the current study were to extract pyocyanin from Pseudomonas aeruginosa clinical isolates, characterize its chemical nature, and assess its biological activity against different bacteria and cancer cells. Due to its diverse bioactive properties, pyocyanin, being one of the virulence factors of P. aeruginosa, holds a promising, safe, and available therapeutic potential.

METHODS

30 clinical P. aeruginosa isolates were collected from different sources of infections and identified by routine methods, the VITEK 2 compact system, and 16 S rRNA. The phenazine-modifying genes (phzM, phzS) were identified using polymerase chain reaction (PCR). Pyocyanin chemical characterization included UV-Vis spectrophotometry, Fourier Transform Infra-Red spectroscopy (FTIR), Gas Chromatography-Mass Spectrometry (GC-MS), and Liquid Chromatography-Mass Spectrometry (LC-MS). The biological activity of pyocyanin was explored by determining the MIC values against different clinical bacterial strains and assessing its anticancer activity against A549, MDA-MB-231, and Caco-2 cancer cell lines using cytotoxicity, wound healing and colony forming assays.

RESULTS

All identified isolates harboured at least one of the phzM or phzS genes. The co-presence of both genes was demonstrated in 13 isolates. The UV-VIS absorbance peaks were maxima at 215, 265, 385, and 520 nm. FTIR could identify the characteristic pyocyanin functional groups, whereas both GC-MS and LC-MS elucidated the chemical formula C11H18N2O2, with a molecular weight 210. The quadri-technical analytical approaches confirmed the chemical nature of the extracted pyocyanin. The extract showed broad-spectrum antibacterial activity, with the greatest activity against Bacillus, Staphylococcus, and Streptococcus species (MICs 31.25-125 µg/mL), followed by E. coli isolates (MICs 250-1000 µg/mL). Regarding the anticancer activity, the pyocyanin extract showed IC50 values against A549, MDA-MB-231, and Caco-2 cancer cell lines of 130, 105, and 187.9 µg/mL, respectively. Furthermore, pyocyanin has markedly suppressed colony formation and migratory abilities in these cells.

CONCLUSIONS

The extracted pyocyanin has demonstrated to be a potentially effective candidate against various bacterial infections and cancers. Hence, the current findings could contribute to producing this natural compound easily through an affordable method. Nonetheless, future studies are required to investigate pyocyanin's effects in vivo and analyse the results of combining it with other traditional antibiotics or anticancer drugs.

Diagnosing viral gastro-enteritis using the fully automated sample-in, result-out STARlet All in one system (AIOS)

The STARlet All-In-One system is a modular platform that integrates the complete molecular diagnostic workflow from nucleic acid extraction of clinical samples to PCR set-up and amplification. The platform was evaluated in comparison with laboratory developed tests (LDT) on fecal samples from patients with suspected viral gastro-enteritis. In a retrospective study, 72 positive samples were analysed, including all pathogens detected by the Seegene Allplex™ GI-virus assay, adenovirus, astrovirus, norovirus GI and GII, sapovirus, and rotavirus. Concordant results were obtained for 69 samples (96 %). Three discordant results were observed, one norovirus GII positive that gave an invalid result in the AIOS and two samples that were negative in the AIOS. One adenovirus positive that was subtyped as a genotype 2 virus, which is not associated with gastro-enteritis, and a sapovirus. In the prospective part of the study, 661 fecal samples were included. A total of 61 positive samples were detected, of which 60 were also detected by the AIOS. One norovirus GII positive sample (CT 35.2) was tested negative in the AIOS. Two additional sapovirus positive samples, CT 37 and 38, were detected by the AIOS but not by the LDT. The STARlet All-In-One platforms results in an automated molecular workflow with reduced hands-on time and enables running assays during out of office hours. Application of the Seegene Allplex™ GI-virus assay showed excellent concordance to the current diagnostic LDT. In a prospective comparison, only three discordant results were observed, all with CT values over 35 and therefore unlikely of clinical relevance.

Epidemiological and Genetic Characteristics of Respiratory Viral Coinfections with Different Variants of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)

This study aimed to determine the incidence and etiological, seasonal, and genetic characteristics of respiratory viral coinfections involving severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Between October 2020 and January 2024, nasopharyngeal samples were collected from 2277 SARS-CoV-2-positive patients. Two multiplex approaches were used to detect and sequence SARS-CoV-2, influenza A/B viruses, and other seasonal respiratory viruses: multiplex real-time polymerase chain reaction (PCR) and multiplex next-generation sequencing. Coinfections of SARS-CoV-2 with other respiratory viruses were detected in 164 (7.2%) patients. The most common co-infecting virus was respiratory syncytial virus (RSV) (38 cases, 1.7%), followed by bocavirus (BoV) (1.2%) and rhinovirus (RV) (1.1%). Patients ≤ 16 years of age had the highest rate (15%) of mixed infections. Whole-genome sequencing produced 19 complete genomes of seasonal respiratory viral co-pathogens, which were subjected to phylogenetic and amino acid analyses. The detected influenza viruses were classified into the genetic groups 6B.1A.5a.2a and 6B.1A.5a.2a.1 for A(H1N1)pdm09, 3C.2a1b.2a.2a.1 and 3C.2a.2b for A(H3N2), and V1A.3a.2 for the B/Victoria lineage. The RSV-B sequences belonged to the genetic group GB5.0.5a, with HAdV-C belonging to type 1, BoV to genotype VP1, and PIV3 to lineage 1a(i). Multiple amino acid substitutions were identified, including at the antibody-binding sites. This study provides insights into respiratory viral coinfections involving SARS-CoV-2 and reinforces the importance of genetic characterization of co-pathogens in the development of therapeutic and preventive strategies.

Recent development and fighting strategies for lincosamide antibiotic resistance

SUMMARYLincosamides constitute an important class of antibiotics used against a wide range of pathogens, including methicillin-resistant Staphylococcus aureus. However, due to the misuse of lincosamide and co-selection pressure, the resistance to lincosamide has become a serious concern. It is urgently needed to carefully understand the phenomenon and mechanism of lincosamide resistance to effectively prevent and control lincosamide resistance. To date, six mobile lincosamide resistance classes, including lnu, cfr, erm, vga, lsa, and sal, have been identified. These lincosamide resistance genes are frequently found on mobile genetic elements (MGEs), such as plasmids, transposons, integrative and conjugative elements, genomic islands, and prophages. Additionally, MGEs harbor the genes that confer resistance not only to antimicrobial agents of other classes but also to metals and biocides. The ultimate purpose of discovering and summarizing bacterial resistance is to prevent, control, and combat resistance effectively. This review highlights four promising strategies, including chemical modification of antibiotics, the development of antimicrobial peptides, the initiation of bacterial self-destruct program, and antimicrobial stewardship, to fight against resistance and safeguard global health.

Prevalence of Human Toxoplasmosis in Spain Throughout the Three Last Decades (1993-2023): A Systematic Review and Meta-analysis

Humans are infected by Toxoplasma gondii worldwide and its consequences may seriously affect an immune deprived population such as HIV and transplanted patients or pregnant women and foetuses. A deep knowledge of toxoplasmosis seroprevalence in Spain is needed in order to better shape health policies and educational programs. We present the results of the first systematic review and meta-analysis on the human prevalence for this disease in Spain. Databases (PubMed, Web of Science, SCOPUS and Teseo) were searched for relevant studies that were published between January 1993 and December 2023 and all population-based cross-sectional and longitudinal studies reporting the human seroprevalence in Spain were revised. Within the population analysed, our targeted groups were immunocompetent population, pregnant women and immunocompromised patients. Among 572 studies and 35 doctoral theses retrieved, 15 studies and three doctoral theses were included in the meta-analysis. A random effects model was used for the meta-analyses due to the high heterogeneity found between studies (I2: 99.97), since it is a statistically conservative model, in addition to allowing better external validity. The global pooled seroprevalence was 32.3% (95% CI 28.7-36.2%). Most of the studies carried out were in pregnant women and the meta-analysis reported that the pooled seroprevalence of toxoplasmosis in pregnant women in Spain was 24.4% (24,737/85,703, 95% CI 21.2-28.0%), based on the random effects model. It is recommended to continue monitoring the seroprevalence status of T. gondii in order to obtain essential guidelines for the prevention and control of the infection in the population.

Association between volume of lung damage and endoplasmic reticulum stress expression among severe COVID-19 ICU patients

Introduction

Links have been established between SARS-CoV-2 and endoplasmic reticulum stress (ERS). However, the relationships between inflammation, ERS, and the volume of organ damage are not well known in humans. The aim of this study was to explore whether ERS explains lung damage volume (LDV) among COVID-19 patients admitted to the intensive care unit (ICU).

Materials and methods

We conducted a single-center retrospective study (ancillary analysis of a prospective cohort) including severe COVID-19 ICU patients who had a chest computed tomography (CT) scan 24 h before/after admission to assess LDV. We performed two multivariate linear regression models to identify factors associated with plasma levels of 78 kDa-Glucose-Regulated Protein (GRP78; ERS marker) and Interleukin-6 (IL-6; inflammation marker) at admission.

Results

Among 63 patients analyzed, GRP78 plasma level was associated with LDV in both multivariate models (β = 22.23 [4.08;40.38]; p = 0.0179, β = 20.47 [0.74;40.20]; p = 0.0423) but not with organ failure (Sequential Organ Failure Assessment (SOFA) score) at admission (r = 0.03 [-0.22;0.28]; p = 0.2559). GRP78 plasma level was lower among ICU survivors (1539.4 [1139.2;1941.1] vs. 1714.2 [1555.2;2579.1] pg./mL. respectively; p = 0.0297). IL-6 plasma level was associated with SOFA score at admission in both multivariate models (β = 136.60 [65.50;207.70]; p = 0.0003, β = 193.70 [116.60;270.90]; p < 0.0001) but not with LDV (r = 0.13 [-0.14;0.39]; p = 0.3219). IL-6 plasma level was not different between ICU survivors and non-survivors (12.2 [6.0;43.7] vs. 30.4 [12.9;69.7] pg./mL. respectively; p = 0.1857). There was no correlation between GRP78 and IL-6 plasma levels (r = 0.13 [-0.13;0.37]; p = 0.3106).

Conclusion

Among severe COVID-19 patients, ERS was associated with LDV but not with systemic inflammation, while systemic inflammation was associated with organ failure but not with LDV.

Seroprevalence study in humans and molecular detection in Rhipicephalus sanguineus ticks of severe fever with thrombocytopenia syndrome virus in Thailand

Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging tick-borne virus with a mortality rate of up to 30%. First identified in China in 2009, it was later reported in other Asian countries, including Thailand in 2020. SFTSV has been detected in several tick species, including Rhipicephalus sanguineus, known for infesting dogs. We conducted a seroprevalence study of SFTSV in Bangkok and Nong Khai, Thailand, by analyzing 1162 human samples collected between 2019 and 2023. The testing method relied on IgG detection using ELISA and confirmed though a virus seroneutralization test. The results indicated that out of the participants, 12 (1.1%) tested positive for anti-SFTSV IgG antibodies; however, none exhibited positive results in the seroneutralization assay. Additionally, molecular detection of SFTSV, Crimean-Congo hemorrhagic fever (CCHF), Coxiella spp., Bartonella spp., and Rickettsia spp. was performed on 433 Rh. sanguineus ticks collected from 49 dogs in 2023 in Chachoengsao Province, Thailand. No evidence of these pathogens was found in ticks. These findings highlight the importance of exploring viral cross-reactivity. Furthermore, it is important to conduct additional studies to isolate SFTSV from animals and ticks in order to identify the potential transmission routes contributing to human and animal infections in Thailand.

Seven draft genome sequences of Streptococcus canis strains, revealing reduced penicillin-G susceptibility

We report seven draft genome sequences of Streptococcus canis strains revealing reduced penicillin-G susceptibility. The genomes measured 2.054-2.385 Mbp, with G+C contents of 38.8%-39.6%. Amino acid substitutions in penicillin-binding proteins were characterized as compared with those of NCTC 12191(T) genome sequence (GenBank accession number NZ_LR134293.1).

SLIRP promotes autoimmune diseases by amplifying antiviral signaling via positive feedback regulation

The abnormal innate immune response is a prominent feature underlying autoimmune diseases. One emerging factor that can trigger dysregulated immune activation is cytosolic mitochondrial double-stranded RNAs (mt-dsRNAs). However, the mechanism by which mt-dsRNAs stimulate immune responses remains poorly understood. Here, we discover SRA stem-loop interacting RNA binding protein (SLIRP) as a key amplifier of mt-dsRNA-triggered antiviral signals. In autoimmune diseases, SLIRP is commonly upregulated, and targeted knockdown of SLIRP dampens the interferon response. We find that the activation of melanoma differentiation-associated gene 5 (MDA5) by exogenous dsRNAs upregulates SLIRP, which then stabilizes mt-dsRNAs and promotes their cytosolic release to activate MDA5 further, augmenting the interferon response. Furthermore, the downregulation of SLIRP partially rescues the abnormal interferon-stimulated gene expression in autoimmune patients' primary cells and makes cells vulnerable to certain viral infections. Our study unveils SLIRP as a pivotal mediator of interferon response through positive feedback amplification of antiviral signaling.

Global prevalence of Borrelia burgdorferi and Anaplasma phagocytophilum coinfection in Ixodes tick populations: protocol for a systematic review and meta-analysis

INTRODUCTION

Ixodes ticks are pivotal in transmitting diseases like Lyme disease and human granulocytic anaplasmosis, caused by Borrelia burgdorferi and Anaplasma phagocytophilum, respectively. These pathogens not only affect humans through single or multiple tick bites but also pose risks to animal hosts, leading to potential coinfections. Despite regional studies indicating significant prevalence, their global coinfection data remain sparse. This study aims to bridge this gap through a systematic review and meta-analysis of B. burgdorferi and A. phagocytophilum coinfections in Ixodes ticks worldwide. Addressing data limitations and study variability, it seeks to provide a nuanced understanding of coinfection patterns, their epidemiological implications and inform targeted prevention strategies.

METHODS AND ANALYSIS

Following Preferred Reporting Items for Systematic Review and Meta-analysis Protocols 2015 guidelines and PROSPERO registration, this study will undertake a thorough database search without constraints on language or publication date, using standardised screening and data extraction protocols. The quality and bias of studies will be evaluated using Joanna Briggs Institute tools. In the statistical analysis phase, conducted in R, we will initially determine the use of fixed or random-effects models based on the assessment of data heterogeneity. This choice will guide the framework for subsequent analyses. Within the selected model's framework, we will perform subgroup analyses and meta-regression to investigate the effects of various factors, ensuring that each step is tailored to the initial model selection to maintain analytical consistency.

ETHICS AND DISSEMINATION

As this study does not involve clinical research or data collection from subjects, ethical approval is not required. We will uphold ethical standards in synthesising and reporting data. Study outcomes will be published in peer-reviewed journals, communicating findings to the scientific community and contributing to the understanding of Ixodes tickborne diseases.

PROSPERO REGISTRATION NUMBER

CRD42023449735.

Global prevalence of mutation in the mgrB gene among clinical isolates of colistin-resistant Klebsiella pneumoniae: a systematic review and meta-analysis

Background

Colistin is used as a last resort for managing infections caused by multidrug-resistant bacteria. However, the high emergence of colistin-resistant strains has restricted the clinical use of this antibiotic in the clinical setting. In the present study, we evaluated the global prevalence of the mutation in the mgrB gene, one of the most important mechanisms of colistin resistance in Klebsiella pneumoniae.

Methods

Several databases, including Scopus, Medline (via PubMed), and Web of Science, were searched (until August 2023) to identify those studies that address the mgrB mutation in clinical isolates of K. pneumoniae. Using Stata software, the pooled prevalence of mgrB mutation and subgroup analyses for the year of publication, country, continent, mgrB mutation types, and detection methods of mgrB mutation were analyzed.

Results

Out of the 115 studies included in the analysis, the prevalence of mgrB mutations in colistin-resistant K. pneumoniae isolates was estimated at 65% of isolates, and mgrB variations with insertional inactivation had the highest prevalence among the five investigated mutations with 69%. The year subgroup analysis indicated an increase in mutated mgrB from 46% in 2014 to 61% in 2022. Europe had the highest prevalence of mutated mgrB at 73%, while Africa had the lowest at 54%.

Conclusion

Mutations in the mgrB gene are reported as one of the most common mechanisms of colistin resistance in K. pneumoniae, and the results of the present study showed that 65% of the reported colistin-resistant K. pneumoniae had a mutation in this gene.

Pathogenic diversification of the gut commensal Providencia alcalifaciens via acquisition of a second type III secretion system

Providencia alcalifaciens is a Gram-negative bacterium found in a wide variety of water and land environments and organisms. It has been isolated as part of the gut microbiome of animals and insects, as well as from stool samples of patients with diarrhea. Specific P. alcalifaciens strains encode gene homologs of virulence factors found in other pathogenic members of the same Enterobacterales order, such as Salmonella enterica serovar Typhimurium and Shigella flexneri. Whether these genes are also pathogenic determinants in P. alcalifaciens is not known. Here we have used P. alcalifaciens 205/92, a clinical isolate, with in vitro and in vivo infection models to investigate P. alcalifaciens -host interactions at the cellular level. Our particular focus was the role of two type III secretion systems (T3SS) belonging to the Inv-Mxi/Spa family. T3SS 1b is widespread in Providencia spp. and encoded on the chromosome. T3SS 1a is encoded on a large plasmid that is present in a subset of P. alcalifaciens strains, which are primarily isolates from diarrheal patients. Using a combination of electron and fluorescence microscopy and gentamicin protection assays we show that P. alcalifaciens 205/92 is internalized into eukaryotic cells, rapidly lyses its internalization vacuole and proliferates in the cytosol. This triggers caspase-4 dependent inflammasome responses in gut epithelial cells. The requirement for the T3SS 1a in entry, vacuole lysis and cytosolic proliferation is host-cell type specific, playing a more prominent role in human intestinal epithelial cells as compared to macrophages. In a bovine ligated intestinal loop model, P. alcalifaciens colonizes the intestinal mucosa, inducing mild epithelial damage with negligible fluid accumulation. No overt role for T3SS 1a or T3SS 1b was seen in the calf infection model. However, T3SS 1b was required for the rapid killing of Drosophila melanogaster . We propose that the acquisition of two T3SS by horizontal gene transfer has allowed P. alcalifaciens to diversify its host range, from a highly virulent pathogen of insects to an opportunistic gastrointestinal pathogen of animals.

Antimicrobial resistance patterns in Streptococcus dysgalactiae in a One Health perspective

Background

Streptococcus dysgalactiae (SD) is an important pathogen in humans as well as in a broad range of animal species. Escalating rates of antibiotic resistance in SD has been reported in both human and veterinary clinical practice, but the dissemination of resistance determinants has so far never been examined in a One Health Perspective. We wanted to explore the occurrence of zoonotic transmission of SD and the potential for exchange of resistance traits between SD from different host populations.

Methods

We compared whole genome sequences and phenotypical antimicrobial susceptibility of 407 SD isolates, comprising all isolates obtained from human bloodstream infections in 2018 (n = 274) and available isolates associated with animal infections from the years 2018 and 2019 (n = 133) in Norway.

Results

Antimicrobial resistance genes were detected in 70 (26%), 9 (25%) and 2 (2%) of the isolates derived from humans, companion animals and livestock, respectively. Notably, distinct host associated genotypic resistomes were observed. The erm(A) gene was the dominant cause of erythromycin resistance in human associated isolates, whereas only erm(B) and lsa(C) were identified in SD isolates from animals. Moreover, the tetracycline resistance gene tet(O) was located on different mobile genetic elements in SD from humans and animals. Evidence of niche specialization was also evident in the phylogenetic analysis, as the isolates could be almost perfectly delineated in accordance with host species. Nevertheless, near identical mobile genetic elements were observed in four isolates from different host species including one human, implying potential transmission of antibiotic resistance between different environments.

Conclusion

We found a phylogenetic delineation of SD strains in line with host adapted populations and niche specialization. Direct transmission of strains or genetic elements carrying resistance genes between SD from different ecological niches appears to be rare in our geographical region.

Are Pathogenic Leptospira Species Ubiquitous in Urban Recreational Parks in Sydney, Australia?

Leptospirosis is a zoonotic disease caused by the spirochete bacteria Leptospira spp. From December 2017 to December 2023, a total of 34 canine leptospirosis cases were reported in urban Sydney, Australia. During the same spatio-temporal frame, one locally acquired human case was also reported. As it was hypothesised that human residents and companion dogs might both be exposed to pathogenic Leptospira in community green spaces in Sydney, an environmental survey was conducted from December 2023 to January 2024 to detect the presence of pathogenic Leptospira DNA in multipurpose, recreational public parks in the council areas of the Inner West and City of Sydney, Australia. A total of 75 environmental samples were collected from 20 public parks that were easily accessible by human and canine visitors. Quantitative PCR (qPCR) testing targeting pathogenic and intermediate Leptospira spp. was performed, and differences in detection of Leptospira spp. between dog-allowed and dog-prohibited areas were statistically examined. The global Moran's Index was calculated to identify any spatial autocorrelation in the qPCR results. Pathogenic leptospires were detected in all 20 parks, either in water or soil samples (35/75 samples). Cycle threshold (Ct) values were slightly lower for water samples (Ct 28.52-39.10) compared to soil samples (Ct 33.78-39.77). The chi-squared test and Fisher's exact test results were statistically non-significant (p > 0.05 for both water and soil samples), and there was no spatial autocorrelation detected in the qPCR results (p > 0.05 for both sample types). Although further research is now required, our preliminary results indicate the presence of pathogenic Leptospira DNA and its potential ubiquity in recreational parks in Sydney.

Genomic characterization of Staphylococcus aureus isolated from patients admitted to intensive care units of a tertiary care hospital: epidemiological risk of nasal carriage of virulent clone during admission

We conducted a molecular epidemiological study of Staphylococcus aureus using whole-genome sequence data and clinical data of isolates from nasal swabs of patients admitted to the intensive care unit (ICU) of Hiroshima University hospital. The relationship between isolate genotypes and virulence factors, particularly for isolates that caused infectious diseases during ICU admission was compared with those that did not. The nasal carriage rates of methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) in patients admitted to the ICU were 7.0% and 20.1%, respectively. The carriage rate of community-acquired (CA)-MRSA was 2.3%, accounting for 32.8% of all MRSA isolates. Whole-genome sequencing analysis of the MRSA isolates indicated that most, including CA-MRSA and healthcare-associated (HA)-MRSA, belonged to clonal complex (CC) 8 [sequence type (ST) 8] and SCCmec type IV. Furthermore, results for three disease foci (pneumonia, skin and soft tissue infection, and deep abscess) and the assessment of virulence factor genes associated with disease conditions [bacteremia, acute respiratory distress syndrome (ARDS), disseminated intravascular coagulopathy (DIC), and septic shock] suggested that nasal colonization of S. aureus clones could represent a risk for patients within the ICU. Particularly, MRSA/J and MSSA/J may be more likely to cause deep abscess infection; ST764 may cause ventilation-associated pneumonia, hospital-acquired pneumonia and subsequent bacteremia, and ARDS, and tst-1-positive isolates may cause DIC onset.IMPORTANCENasal colonization of MRSA in patients admitted to the intensive care unit (ICU) may predict the development of MRSA infections. However, no bacteriological data are available to perform risk assessments for Staphylococcus aureus infection onset. In this single-center 2-year genomic surveillance study, we analyzed all S. aureus isolates from nasal swabs of patients admitted to the ICU and those from the blood or lesions of in-patients who developed infectious diseases in the ICU. Furthermore, we identified the virulent clones responsible for causing infectious diseases in the ICU. Herein, we report several virulent clones present in the nares that are predictive of invasive infections. This information may facilitate the design of preemptive strategies to identify and eradicate virulent MRSA strains, reducing nosocomial infections within the ICU.

Carbapenemase-producing Enterobacterales isolated from hospital sinks: molecular relationships with isolates from patients and the change in contamination status after daily disinfection with sodium hypochlorite

Objective

This study aimed to investigate the contamination status of hospital sinks with carbapenemase-producing Enterobacterales (CPE), the efficacy of daily cleaning with sodium hypochlorite, and the relationships between CPEs isolated from contaminated sinks and patients.

Design

Pre/postintervention surveys of the CPE-contaminated sinks.

Setting

Hospital wards including pediatric intensive care unit in a children's hospital.

Participants

Consenting CPE-colonized patients admitted between November 2018 and June 2021 in our hospital.

Methods

Environmental culture of 180 sinks from nine wards in our hospital was performed three times with an interval of 2 years (2019, 2021, 2023). Molecular typing of the isolated strains from the sinks and patients was performed. After the first surveillance culture, we initiated daily disinfection of the sinks using sodium hypochlorite.

Results

Before the intervention, we detected 30 CPE-positive sinks in 2019. After the intervention with sodium hypochlorite, we observed a substantial decline in the number of sinks contaminated with CPE; 13 in 2021 and 6 in 2023. However, the intervention did not significantly reduce the number of CPE-contaminated sinks used for the disposal of nutrition-rich substances. The CPE isolates from the patients and those from the sinks of the wards or floors where they were admitted tended to have similar pulse-field gel electrophoresis patterns.

Conclusion

Contaminated sinks could be reservoirs of disseminating CPE to the patients. Daily disinfection of sinks with sodium hypochlorite may be effective in eliminating CPE, although the effect could be weaker in sinks with a greater risk of contact with nutrition-rich substances.

Complement-dependent virion lysis mediated by dengue-Zika virus cross-reactive antibodies correlates with protection from severe dengue disease

Primary infection with one of four dengue virus serotypes (DENV1-4) may generate antibodies that protect or enhance subsequent secondary heterotypic infections. However, the characteristics of heterotypic cross-reactive antibodies associated with protection from symptomatic infection and severe disease are not well-defined. We selected plasma samples collected before a secondary DENV heterotypic infection that was classified either as dengue fever (DF, n = 31) or dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS, n = 33) from our longstanding pediatric cohort in Nicaragua. We screened various antibody properties to determine the features correlated with protection from DHF/DSS. Protection was associated with high levels of binding of various antibody isotypes, IgG subclasses and effector functions, including antibody-dependent complement deposition, ADCD. Although the samples were derived from DENV-exposed, Zika virus (ZIKV)-naïve individuals, the protective ADCD association was stronger when assays were conducted with recombinant ZIKV antigens. Further, we showed that a complement-mediated virion lysis (virolysis) assay conducted with ZIKV virions was strongly associated with protection, a finding reproduced in an independent sample set collected prior to secondary heterotypic inapparent versus symptomatic DENV infection. Virolysis was the main antibody feature correlated with protection from DHF/DSS and severe symptoms, such as thrombocytopenia, hemorrhagic manifestations, and plasma leakage. Hence, anti-DENV antibodies that cross-react with ZIKV, target virion-associated epitopes, and mediate complement-dependent virolysis are correlated with protection from secondary symptomatic DENV infection and DHF/DSS. These findings may support the rational design and evaluation of dengue vaccines and development of therapeutics.

Assessing the Prevalence and Dynamics of Emerging Campylobacterales in Human Stool Samples in Brussels by Filtration Culture

Thermophilic C. jejuni/coli is reported to be the first bacterial cause of gastroenteritis worldwide and the most common zoonosis in Europe. Although non-jejuni/coli Campylobacter sp. are increasingly suspected to be responsible for diarrhoea or to be involved in inflammatory bowel disease, they remain poorly isolated due to their fastidious and non-thermophilic nature. Additionally, they are not targeted by commercial syndromic PCR assays. In this study, we present routine diagnostic results over 6 years (2017-2019 and 2021-2023) of Campylobacter sp. and related species, obtained by optimised culture from 51,065 stools by both 0.65 µm pore filtration on antibiotic-free agar, incubated in an H2-enriched atmosphere at 37 °C (also known as the Cape Town protocol), and the use of selective inhibitory Butzler medium incubated at 42 °C. This allowed the isolation of 16 Campylobacter species, 2 Aliarcobacter species, and 2 Helicobacter species, providing a completely different view of the epidemiology of Campylobacterales, in which C. jejuni/coli represents only 30.0% of all isolates, while C. concisus represents 44.4%. C. ureolyticus, representing only 5.5% of all Campylobacterales pre-COVID-19, represented 20.6% of all strains post-COVID-19 (218% increase; p < 0.05). At the same time, the proportions of C. jejuni, C. coli, and C. concisus decreased by 37, 53, and 28%, respectively (p < 0.05).

A novel variant in Salmonella genomic island 1 of multidrug-resistant Salmonella enterica serovar Kentucky ST198

Salmonella enterica serovar Kentucky ST198 is a major health threat due to its resistance to ciprofloxacin and several other drugs, including third-generation cephalosporins. Many drug-resistant genes have been identified in the Salmonella genomic island 1 variant K (SGI1-K). In this study, we investigated the antimicrobial resistance (AMR) profile and genotypic relatedness of two isolates of ciprofloxacin-resistant (CIPR) S. Kentucky ST198 from poultry in Northeastern Thailand. We successfully assembled the complete genomes of both isolates, namely SSSE-01 and SSSE-03, using hybrid de novo assembly of both short- and long-read sequence data. The complete genomes revealed their highly similar genomic structures and a novel variant of SGI1-K underlying multidrug-resistant (MDR) patterns, including the presence of blaTEM-1b, which confers resistance to beta-lactams, including cephalosporins and lnu(F) which confers resistance to lincomycin and other lincosamides. In addition, the chromosomal mutations in the quinolone resistance-determining region (QRDR) were found at positions 83 (Ser83Phe) and 87 (Asp87Asn) of GyrA and at positions 57 (Thr57Ser) and 80 (Ser80Ile) of ParC suggesting high resistance to ciprofloxacin. We also compared SSSE-01 and SSSE-03 with publicly available complete genome data and revealed significant variations in SGI1-K genetic structures and variable relationships to antibiotic resistance. In comparison to the other isolates, SGI1-K of SSSE-01 and SSSE-03 had a relatively large deletion in the backbone, spanning from S011 (traG∆) to S027 (resG), and the inversion of the IS26-S044∆-yidY segment. Their MDR region was characterized by the inversion of a large segment, including the mer operon and the relocation of IntI1 and several resistance genes downstream of the IS26-S044∆-yidY segment. These structural changes were likely mediated by the recombination of IS26. The findings broaden our understanding of the possible evolution pathway of SGI1-K in fostering drug resistance, which may provide opportunities to control these MDR strains.IMPORTANCEThe emergence of ciprofloxacin-resistant (CIPR) Salmonella Kentucky ST198 globally has raised significant concerns. This study focuses on two poultry isolates from Thailand, revealing a distinct Salmonella genomic island 1 variant K (SGI1-K) genetic structure. Remarkably, multiple antibiotic resistance genes (ARGs) were identified within the SGI1-K as well as other locations in the chromosome, but not in plasmids. Comparing the SGI1-K genetic structures among global and even within-country isolates unveiled substantial variations. Intriguingly, certain isolates lacked ARGs within the SGI1-K, while others had ARGs relocated outside. The presence of chromosomal extended-spectrum β-lactamase (ESBL) genes and lincosamide resistance, lnu(F), gene, could potentially inform the choices of the treatment of CIPRS. Kentucky ST198 infections in humans. This study highlights the importance of understanding the diverse genetic structures of SGI1-K and emphasizes the role of animals and humans in the emergence of antimicrobial resistance.

Active surveillance of immunization adverse effects: a multicentre, open-label, three-arm randomized uncontrolled trial in Ethiopia

BACKGROUND

Participant-centred active adverse event following immunization (AEFI) surveillance can offer real-time vaccine safety data and help in signal detection. This study aimed to evaluate the effectiveness of participant-centred active adverse events (AEs) surveillance following measles immunization in Gedeo Zone health facilities in Ethiopia.

METHODS

An open-label, multicentred, three-arm randomized uncontrolled trial was conducted from 1 June to 21 October 2023. After assessing enrolment eligibility, the study participants were randomized into three groups (short message service [SMS], telephone interview, and diary card). They were expected to report AEs in children 1 week after receiving immunization. Binary and multivariable logistic regression and χ2 tests were used to analyse the data.

RESULTS

Among the 396 participants randomized into the three groups, 80.8% (320 participants) reported back about their children's AE status. Participants in the telephone interview group exhibited a substantially superior response rate (93.2% of 132 participants; p<0.00001) compared with the SMS (71.2%) and diary card (78%) groups. The likelihood of reporting the status of AEs experienced by children was lower by 77% (adjusted odds ratio 0.23 [95% confidence interval 0.1 to 0.52], p-value <0.00001) in the diary card group compared with the telephone interview group.

CONCLUSIONS

In this study, a telephone interview was found to be the best method for AEFI reporting. Participant-centred active AE surveillance could potentially permit more rapid identification of emerging safety signals. Trial registration:  https://clinicaltrials.gov/ct2/show/NCT05803538.

Wide distribution of plasmid mediated quinolone resistance gene, qnrS, among Salmonella spp. isolated from canal water in Thailand

AIMS

This research focused on assessing the prevalence of plasmid-mediated quinolone resistance (PMQR) determinants and antimicrobial susceptibility in Salmonella strains isolated from Thai canal water.

METHODS AND RESULTS

From 2016 to 2020, 333 water samples were collected from six canals across Bangkok, Thailand. Salmonella spp. was isolated, PMQR genes were detected through polymerase chain reactions, and the antimicrobial susceptibility was examined using the disk diffusion method. The results indicated a 92.2% prevalence of Salmonella spp. in canal water, being serogroups B and C the most frequently detected. Overall, 35.3% of isolates harbored PMQR genes, being qnrS the most prevalent gene (97.2%, n = 137/141). Other PMQR genes, including qnrB, qnrD, oqxAB, and aac(6')-Ib-cr, were detected. Notably, six isolates harbored multiple PMQR genes. Furthermore, 9.3% and 3.8% of the overall isolates were resistant to nalidixic acid (NAL) and ciprofloxacin (CIP), respectively. PMQR-positive isolates showed higher rates of non-susceptibility to both NAL (48.2%, n = 68/141) and CIP (92.2%, n = 130/141) compared to PMQR-negative isolates (NAL: 8.9%, n = 23/258; CIP: 11.2%, n = 30/258).

CONCLUSIONS

The high prevalence of Salmonella spp., significant PMQR-positive, and reduced susceptibility isolates in canal water is of public health concern in Bangkok.

Clinical characteristics and outcomes of patients with Herpes Simplex Encephalitis in Vietnam: a retrospective study

BACKGROUND

Herpes simplex encephalitis (HSE) is an important central nervous infection with severe neurological sequelae. The aim of this study was to describe clinical characteristic and outcomes of patients with HSE in Vietnam.

METHODS

This was a retrospective study of 66 patients with herpes simplex encephalitis who admitted to the National Hospital for Tropical Diseases, Hanoi, Vietnam from 2018 to 2021. The detection of herpes simplex virus (HSV) in cerebrospinal fluid was made by the real-time PCR assay. We reported the clinical manifestation on admission and evaluated clinical outcomes at the hospital discharge by modified Rankin Scale (mRS). Multivariate logistic regression analysis was used to analyze the independent risk factors of severe outcomes.

RESULTS

Of the 66 patients with laboratory confirmed HSE, the median age was 53 years (IQR 38-60) and 44 patients (69.7%) were male. The most common manifestations included fever (100%), followed by the consciousness disorder (95.5%). Other neurological manifestation were seizures (36.4%), memory disorders (31.8%), language disorders (19.7%) and behavioral disorders (13.6%). Conventional magnetic resonance imaging (MRI) showed 93.8% patients with temporal lobe lesions, followed by abnormalities in insula (50%), frontal lobe (34.4%) and 48.4% of patients had bilateral lesions. At discharge, 19 patients (28.8%) completely recovered, 15 patients (22.7%) had mild sequelae, 28 patients (42.4%) had moderate to severe sequelae. Severe neurological sequelae were memory disorders (55.8%), movement disorders (53.5%), language disorders (30.2%). Multivariate logistic regression analysis showed that Glasgow score decrement at admission, seizures, and time duration from onset of symptoms to the start of Acyclovir treatment > 4 days were independent factors associated with severe outcomes in HSE patients.

CONCLUSION

Glasgow score decrement, seizures and delay treatment with Acyclovir were associated with the poor outcome of patients with HSE.

Update and approach to patients with brain abscess

PURPOSE OF REVIEW

The epidemiology of brain abscess has changed in recent decades. Moreover, acute and long-term management remains challenging with high risks of mortality and neurological sequelae. This review describes recent advances in epidemiology, diagnosis, and treatment of brain abscess.

RECENT FINDINGS

The incidence of brain abscess is increasing, especially among elderly individuals. Important predisposing conditions include dental and ear-nose-throat infections, immuno-compromise, and previous neurosurgery. Molecular-based diagnostics have improved our understanding of the involved microorganisms and oral cavity bacteria including anaerobes are the predominant pathogens. The diagnosis relies upon a combination of magnetic resonance imaging, neurosurgical aspiration or excision, and careful microbiological examinations. Local source control by aspiration or excision of brain abscess combined with long-term antimicrobials are cornerstones of treatment. Long-term management remains important and should address neurological deficits including epilepsy, timely diagnosis and management of comorbidities, and potential affective disorders.

SUMMARY

A multidisciplinary approach to acute and long-term management of brain abscess remains crucial and source control of brain abscess by neurosurgery should be pursued whenever possible. Numerous aspects regarding diagnosis and treatment need clarification. Nonetheless, our understanding of this complicated infection is rapidly evolving.

Genetic characterization of KHM-1 metallo-β-lactamase-producing Enterobacterales isolates from inpatient sources in Osaka, Japan

OBJECTIVES

KHM-1-metallo-β-lactamase-producing Enterobacterales strains, of which only a few have been found, were isolated from four inpatients in Osaka, Japan during 2016 to 2020. We compared whole genomes of the four KHM-1-producing isolates, including one Enterobacter hormaechei subsp. hoffmannii, one Escherichia coli, and two Citrobacter freundii.

METHODS

These isolates were characterized by whole-genome sequencing, comparative analysis of blaKHM-1-encoding plasmids with earlier reported plasmids, and antimicrobial susceptibility tests.

RESULTS

Multilocus sequence typing classified the E. hormaechei subsp. hoffmannii isolate to ST78, the E. coli isolate to ST354, and the two C. freundii isolates to ST95. These isolates harboured various antimicrobial resistance genes aside from blaKHM-1 on their chromosomes and plasmids. In all four isolates, blaKHM-1 was located on 137 kbp to 213 kbp plasmids of IncC replicon type. Although there were common resistance genes such as blaKHM-1-ISEc68, class I integron cassette, and fosG, the four blaKHM-1-encoding plasmids were distinguishable into two lineages based on differences of the resistance gene components and their surrounding regions.

CONCLUSION

Because no epidemiological contact was observed among the inpatients, the blaKHM-1-encoding IncC plasmids might have spread horizontally to multiple bacterial species through repeated recombination and insertion.

Multidrug-resistant Klebsiella pneumoniae clinical isolates producing NDM- and OXA-type carbapenemase in Nepal

OBJECTIVES

The emergence of multidrug-resistant Klebsiella pneumoniae has become a serious problem in medical settings worldwide.

METHODS

A total of 46 isolates of multidrug-resistant K. pneumoniae were obtained from 2 hospitals in Nepal from October 2018 to April 2019.

RESULTS

Most of these isolates were highly resistant to carbapenems, aminoglycosides, and fluoroquinolones with the minimum inhibitory concentrations (MICs) of more than 64 µg/mL. These isolates harboured carbapenemase-encoding genes, including blaNDM-1, blaNDM-5, blaOXA-181 and blaOXA-232, and 16S rRNA methyltransferase-encoding genes, including armA, rmtB, rmtC, and rmtF. Multilocus sequence typing revealed that 44 of 46 isolates were high-risk clones such as ST11 (2%), ST14 (4%), ST15 (11%), ST37 (2%), ST101 (2%), ST147 (28%), ST231 (13%), ST340 (4%), and ST395 (28%). In particular, ST395 isolates, which spread across medical settings in Nepal, co-harboured blaNDM-5 and rmtB on IncFII plasmids and co-harboured blaOXA-181/-232 and rmtF on ColKP3 plasmids. Several isolates harboured blaOXA-181 or blaNDM-5 on their chromosomes and multi-copies of blaNDM-1 or genes encoding 16S rRNA methyltransferases on their plasmids.

CONCLUSIONS

The presented study demonstrates that the high-risk clones of multidrug-resistant K. pneumoniae spread in a clonal manner across hospitals in Nepal.

Severe fever with thrombocytopenia syndrome virus infection attributed to cat contact: A case report in Beijing, China

•SFTSV is detected in host-seeking ticks in rural–urban fringe areas in Beijing. •SFTSV RNA, IgM, and neutralizing antibodies are detected in stray cats in Beijing. •Multiple SFTSV genotypes naturally circulate within ticks in Beijing's urban zones.

BVN008, Diphtheria-tetanus-acellular pertussis combined vaccine has no effects on fertility and prenatal and postnatal developmental toxicity in female Sprague-Dawley rats

Tdap is an acronym for tetanus(T), diphtheria(D), and acellular pertussis(aP), and is a preventive vaccine that combines vaccines against three diseases. BVN008 is a Tdap vaccine designed to protect against three diseases: diphtheria, tetanus, and pertussis. The lower-case "d" and "p" in Td and Tdap means these vaccines use smaller amounts of diphtheria and whooping cough. The lower doses are appropriate for adolescents and adults. The purpose of this study was to identify adverse effects in pregnant or lactating female Sprague-Dawley rats including maternal fertility and toxicity, and development of the embryos, fetus, and pups following intramuscular administration of BVN008. Two groups of 50 female Sprague-Dawley rats were administered four or five intramuscular injections of the vaccine (human dose of 0.5 mL at 4 and 2 weeks before pairing, on gestation day (GD) 8 and 15, and lactation day (LD) 7. A negative control group was administered 0.9% saline at the same dose four or five times. There were no adverse effects on fertility, reproductive performance, or maternal toxicity of the F0 females. There was no effect of developmental toxicity in F1 fetuses and pups including fetal body weight and morphology, postnatal growth, development, and behavior until weaning. Antibodies against tetanus, diphtheria, and pertussis were transferred to the F1 fetuses and F1 pups via placenta and milk. These results demonstrate that BVN008 had no detectable adverse effects in either the F0 female rats, the F1 fetuses or pups.

Epidemiology and Clinical Outcomes of Bacterial Meningitis in Children and Adults in Low- and Middle-Income Countries

Purpose of Review

Despite the availability of effective vaccines against the three primary pathogens (Streptococcus pneumoniae, Haemophilus influenzae type b, and Neisseria meningitidis) that cause bacterial meningitis, this condition remains a significant cause of morbidity, neurologic sequelae, and mortality among children and adults living in low-income and middle-income countries.

Recent Findings

Bacterial meningitis represents a significant public health challenge for national and global health systems. Since vaccine-preventable meningitis remains highly prevalent in low-income and middle-income countries, the World Health Organization (WHO) recently developed a global roadmap to defeating meningitis by 2030 and ameliorating its associated neurological sequelae.

Summary

There is a need for a global approach to surveillance and prevention of bacterial meningitis. Increasing vaccination coverage with conjugate vaccines against pneumococcus and meningococcus with optimal immunization schedules are high-value healthcare interventions. Additionally, overcoming diagnostic challenges and the early institution of empirical antibiotic therapy and, when feasible, adjunctive steroid therapy constitutes the pillars of reducing the disease burden of bacterial meningitis in resource-limited settings.

Severe coinfection of dengue and malaria: A case report

Key Clinical Message

In countries like Sudan, where several infectious diseases are prevalent, health care providers should not be satisfied with initial detection of a single pathogen and whenever it is feasible, they should investigate coinfections. Infections with high mortality or severe morbidity should be prioritized during the differential diagnosis particularly for diseases with similar clinical manifestations to reduce the death and disability rates. However, this requires substantial improvement in the diagnostic capacity.

Abstract

Here we report a case of dengue and malaria coinfection from the southeast region of Sudan, bordering Ethiopia and Eritrea. A 25-year-old male from Sudan presented with symptoms of fever, chills, vomiting, and muscle and joint pain. Laboratory investigations confirmed a coinfection of dengue and malaria, which is assumingly not uncommon in areas heavily syndemic with several diseases but it is severely under-detected, underreported, and underestimated. The case has fully recovered after the supportive care for dengue and chemotherapy treatment for malaria. In such a case, it was important to monitor the patient's recovery and the treatment outcome through clinical indicators and laboratory parameters to update the treatment course whenever needed, according to response. The increasing burden and outbreaks of vector-borne diseases including dengue and malaria in Sudan, indicates the need for improving the implementation of the global vector control response that established by the World Health Organization. Additionally, the increasing prevalent of coinfections is urging substantial improvement in the diagnostic capacity in endemic countries.

Carbapenem and colistin-resistant hypervirulent Klebsiella pneumoniae: An emerging threat transcending the egyptian food chain

BACKGROUND

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a great public health problem and is associated with many disease outbreaks and high mortality rates. Alarmingly, K. pneumoniae has been isolated from food in several recent studies. This study aimed to investigate the prevalence and characteristics of CRKP in food samples from Egypt.

METHODS

A total of 311 food samples (including 116 minced meat, 92 chicken meat, 75 diced meat, and 28 mutton) were collected from local markets in Egypt and were screened for CRKP with the determination of their antimicrobial resistance profiles. The whole genome sequence was done for 23 CRKP isolates to clarify the relationship between CRKP from food and human cases in Egypt using the SNP core genome. The conjugation probability of the blaNDM-5 harboring plasmid was identified using oriTfinder RESULTS: CRKP was isolated from 11% (35/311) of the samples, with 45.71% (16/35) of them showing resistance to colistin, one of the last-resort options for treating CRKP-mediated infections. In addition to the carbapenem and colistin resistance, the CRKP isolates frequently exhibited resistance to multiple antimicrobials including β-lactams, fluoroquinolones, aminoglycosides, tetracyclines, and chloramphenicol. In addition, most of the CRKP were potentially hypervirulent K. pneumoniae (HvKP) identified as phylogroup Kp1 and of high-risk groups as detected in STs reported in many human outbreaks globally, such as ST383 and ST147. The core-genome phylogeny showed similarities between the isolates from this study and those previously isolated from clinical human samples in Egypt. In addition, analysis of the plasmid on which blaNDM is encoded revealed that several antimicrobial resistance genes such as blaOXA-9, blaCTX-M-15, aac(6')-Ib, qnrS1, and several virulence genes are encoded on the same plasmid.

CONCLUSIONS

This study is significant for food safety and public health and is important to further identify the change in the epidemiology of CRKP infections, especially the consumption of contaminated food products.

Unveiling the role of preceding seasonal influenza in the development of bacteremic pneumococcal pneumonia in older adults before the COVID-19 pandemic in Japan

OBJECTIVE

We aimed to investigate the impact of preceding seasonal influenza on the clinical characteristics of adult patients with invasive pneumococcal disease (IPD) in Japan.

METHODS

Data for 1722 adult patients with IPD were analyzed before (2017-2019) and during the COVID-19 pandemic (2020-2022).

RESULTS

The seasonal influenza epidemic disappeared soon after the emergence of the pandemic. Compared with that before the pandemic (66.7%), we observed a lower bacteremic pneumonia proportion in patients with IPD during the pandemic (55.6%). The clinical presentations of IPD cases significantly differed between those with and without preceding influenza. The proportion of bacteremic pneumonia was higher in IPD patients with preceding influenza than in those without in both younger (44.9% vs 84.2%) and older adults (65.5% vs 87.0%) before the pandemic. The case fatality rate was significantly higher in IPD patients with preceding influenza (28.3%) than in those without (15.3%) in older adults before the pandemic (P = 0.020). Male and aging are high risk factors for death in older patients with IPD who had preceding influenza.

CONCLUSION

Our study reveals that preceding seasonal influenza plays a role in the development of bacteremic pneumococcal pneumonia, increasing the risk of death in older adults.

Differential Abundances of Bdellovibrio and Rheinheimera in the Oral Microbiota of Neonates With and Without Clinical Sepsis

BACKGROUND

Neonatal sepsis is associated with high rates of morbidity and mortality, long hospital stays and high cost of care, thereby inflicting a burden on health care systems. Oral care with breast milk has been shown to modify the intestinal tract microbiota and immune system. Herein, we attempted to identify probiotics that may be beneficial to prevent or treat neonatal sepsis.

METHODS

This was a secondary analysis comparing the microbiota during oropharyngeal care in very-low-birth-weight infants with and without clinical sepsis. Oral samples were collected before oral feeding was initiated. The primary outcome was oral microbiota composition including diversity, relative abundance and linear discriminant analysis effect size.

RESULTS

Sixty-three neonates, including 39 and 24 with and without clinical sepsis, respectively, were enrolled. The medians gestational age and birth weight were 29 (27-30) weeks and 1010 (808-1263) g. Neonates with clinical sepsis had lower gestational age, birth weight (both P < 0.001) and lower rate of oral care with breast milk ( P = 0.03), but higher doses and days of antibiotic exposure (both P < 0.001) compared to neonates without clinical sepsis. No differences in alpha and beta diversities were found between groups and Streptococcus agalactiae was the most common bacteria in both groups. Linear discriminant analysis effect size analysis revealed that neonates without clinical sepsis had significantly higher abundances of order Bdellovibrionales, family Bdellovibrionaceae, genus Bdellovibrio and genus Rheinheimera .

CONCLUSIONS

Neonates without clinical sepsis had a significantly greater abundance of the Bdellovibrio and Rheinheimera genera.

Antiviral therapies for the management of persistent coronavirus disease 2019 in immunocompromised hosts: A narrative review

Antiviral agents with activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have played a critical role in disease management; however, little is known regarding the efficacy of these medications in the treatment of SARS-CoV-2 infection in immunocompromised patients, particularly in the management of persistent SARS-CoV-2 positivity. This narrative review discusses the management of persistent coronavirus disease 2019 in immunocompromised hosts, with a focus on antiviral therapies. We identified 84 cases from the literature describing a variety of approaches, including prolonged antiviral therapy (n = 11), combination antivirals (n = 13), and mixed therapy with antiviral and antibody treatments (n = 60). A high proportion had an underlying haematologic malignancy (n = 67, 80%), and were in receipt of anti-CD20 agents (n = 51, 60%). Success was reported in 70 cases (83%) which varied according to the therapy type. Combination therapies with antivirals may be an effective approach for individuals with persistent SARS-CoV-2 positivity, particularly those that incorporate treatments aimed at increasing neutralizing antibody levels. Any novel approaches taken to this difficult management dilemma should be mindful of the emergence of antiviral resistance.

Comparison of Switching Between Antiretroviral Agents Versus Introducing Lipid-lowering Agents for HAART-induced Dyslipidemia

PURPOSE

Highly active antiretroviral therapy (HAART) has brought a significant reduction in HIV/AIDS-related morbidity and mortality. However, metabolic abnormalities (eg, dyslipidemias) have continued to pose significant challenges, warranting a switch between antiretroviral agents and/or the introduction of a statin. Hence, the purposes of this study was to compare the efficacy of switching between antiretroviral agents versus introducing a statin in the long-term management of HAART-induced dyslipidemia in people living with HIV, and to identify the most potent agent in switching therapies.

METHODS

A comprehensive literature search of PubMed and Medline identified articles published from the years 2000 to 2020 in the English language, resulting in 84 articles, 30 of which were selected based on inclusion and exclusion criteria. Information on primary and secondary outcomes was extracted. Statistical analysis was done on the variables, and the differences between groups were considered significant at P < 0.05.

FINDINGS

Statin use was associated with significant reductions in triglycerides and total cholesterol (TC) at 6 weeks (both, P < 0.01). A switch of antiretroviral agents was associated with gradual reductions in TC and triglycerides for up to 48 weeks (both, P < 0.01). Statin use was associated with a reduced CD4 count at 24 weeks (P < 0.01). A switch of antiretroviral agents was associated with an increased CD4 count at 48 weeks (P < 0.01).

IMPLICATIONS

Statins were as effective as switching antiretroviral therapies in the short-term management of TC and triglycerides in patients with HAART-induced dyslipidemia.

Trends in the detection of viruses causing gastroenteritis over a 10-year period and impact of nonpharmaceutical interventions

BACKGROUND

Viral gastroenteritis continues to be a leading cause of death in low-income countries. The impact of nonpharmaceutical interventions (NPIs) on the transmission of gastroenteritis-causing viruses during the COVID-19 pandemic is understudied.

OBJECTIVES

To investigate the 10-year trends of enteric viruses and estimate the impact of implementing and mitigating NPIs.

STUDY DESIGN

Data regarding norovirus, rotavirus, adenovirus, astrovirus, and sapovirus detection were collected from five Korean hospitals between January 2013 and April 2023. We compared positivity between the pre-pandemic, pandemic, and post-pandemic periods. The causal effects of implementing and mitigating NPIs were quantified using the Bayesian Structural Time Series (BSTS) model.

RESULTS

Norovirus was most frequently detected (9.9 %), followed by rotavirus (6.7 %), adenovirus (3.3 %), astrovirus (1.4 %), and sapovirus (0.6 %). During the pandemic, the positivity of all five viruses decreased, ranging from -1.0 % to -8.1 %, with rotavirus showing the greatest decrease. In the post-pandemic period, positivity rebounded for all viruses except for rotavirus. The BSTS model revealed that NPI implementation negatively affected the detection of all five viruses, resulting in reductions ranging from -73.0 % to -91.0 % compared to the prediction, with rotavirus being the least affected. Conversely, NPI mitigation positively affected the detection of all viruses, ranging from 79.0 % to 200.0 %, except for rotavirus.

CONCLUSIONS

Trends observed over 10 years show that NPIs have had a major impact on changes in enteric virus detection. The effect of vaccines, in addition to NPIs, on rotavirus detection requires further investigation. Our findings emphasize the importance of NPIs in infection control and prevention.

A systematic review of global Q fever outbreaks

Q fever is an important zoonotic disease with a worldwide distribution. Outbreaks of Q fever are unpredictable and can affect many people, resulting in a significant burden on public health. The epidemiology of the disease is complex and substantial efforts are required to understand and control Q fever outbreaks. The purpose of this study was to systematically review previous investigations of outbreaks and summarise important epidemiological features. This will improve knowledge of the factors driving the occurrence of Q fever outbreaks and assist decision makers in implementing mitigation strategies. A search of four electronic databases identified 94 eligible articles published in English between 1990 and 2022 that related to 81 unique human Q fever outbreaks. Outbreaks were reported across 27 countries and mostly in industrialised nations. Documented Q fever outbreaks varied in size (2 to 4107 cases) and duration (4 to 1722 days). Most outbreaks (43/81) occurred in communities outside of traditional at-risk occupational settings and were frequently associated with living in proximity to livestock holdings (21/43). Indirect transmission via environmental contamination, windborne spread or fomites was the most common route of infection, particularly for large community outbreaks. Exposure to ruminants and/or their products were confirmed as the principal risk factors for infection, with sheep (28/81) as the most common source followed by goats (12/81) and cattle (7/81). Cooperation and data sharing between human and animal health authorities is valuable for outbreak investigation and control using public health and veterinary measures, but this multisectoral approach was seldom applied (14/81). Increased awareness of Q fever among health professionals and the public may facilitate the early detection of emerging outbreaks that are due to non-occupational, environmental exposures in the community.

The interplay of aging, adipose tissue, and COVID-19: a potent alliance with implications for health

Obesity has emerged as a significant public health challenge. With the ongoing increase in life expectancy, the prevalence of obesity is steadily growing, particularly among older age demographics. The extension of life expectancy frequently results in additional years of vulnerability to chronic health issues associated with obesity in the elderly.The concept of SARS-CoV-2 directly infecting adipose tissue stems from the fact that both adipocytes and stromal vascular fraction cells express ACE2, the primary receptor facilitating SARS-CoV-2 entry. It is noteworthy that adipose tissue demonstrates ACE2 expression levels similar to those found in the lungs within the same individual. Additionally, ACE2 expression in the adipose tissue of obese individuals surpasses that in non-obese counterparts. Viral attachment to ACE2 has the potential to disturb the equilibrium of renin-angiotensin system homeostasis, leading to an exacerbated inflammatory response.Consequently, adipose tissue has been investigated as a potential site for active SARS-CoV-2 infection, suggesting its plausible role in virus persistence and contribution to both acute and long-term consequences associated with COVID-19.This review is dedicated to presenting current evidence concerning the presence of SARS-CoV-2 in the adipose tissue of elderly individuals infected with the virus. Both obesity and aging are circumstances that contribute to severe health challenges, heightening the risk of disease and mortality. We will particularly focus on examining the mechanisms implicated in the long-term consequences, with the intention of providing insights into potential strategies for mitigating the aftermath of the disease.

Antibiotic-Resistance Profiles and Genetic Diversity of Shigella Isolates in China: Implications for Control Strategies

The urgent need for comprehensive and systematic analyses of Shigella as the key pathogen led us to meticulously explore the epidemiology and molecular attributes of Shigella isolates. Accordingly, we procured 24 isolates (10 from Xinjiang and 14 from Wuhan, China) and performed serotype identification and antimicrobial susceptibility testing. Resistance gene detection and homology analysis by polymerase chain reaction and pulsed-field gel electrophoresis (PFGE), respectively, were performed for genetic diversity analysis. All isolates were identified as Shigella flexneri, with 70% (35.4-91.9%) and 30% (8.1-64.6%) of the Xinjiang isolates and 85.7% (56.2-97.5%) and 14.3% (2/14, 2.5-43.9%) of the Wuhan isolates belonging to serotype 2a and serotype 2b, respectively. All isolates displayed resistance to at least two antibiotics and complete resistance to ampicillin. Multidrug resistance (MDR) was recorded in 70.8% (48.8-86.6%) of isolates, with Xinjiang isolates exhibiting relatively higher resistance to ampicillin-sulbactam, piperacillin, ceftriaxone, and aztreonam. Conversely, Wuhan isolates displayed higher MDR and resistance to tetracycline, ciprofloxacin, levofloxacin, and cefepime relative to Xinjiang isolates. Molecular scrutiny of antibiotic-resistance determinants revealed that blaTEM was the main mechanism of ampicillin resistance, blaCTX-M was the main gene for resistance to third- and fourth-generation cephalosporins, and tetB was the predominant gene associated with tetracycline resistance. Four Xinjiang and seven Wuhan isolates shared T1-clone types (>85%), and two Xinjiang and one Wuhan isolates were derived from the T6 clone with a high similarity of 87%. Six PFGE patterns (T1, T2, T5, T6-3, T8, and T10) of S. flexneri were associated with MDR. Thus, there is a critical need for robust surveillance and control strategies in managing Shigella infections, along with the development of targeted interventions and antimicrobial stewardship programs tailored to the distinct characteristics of Shigella isolates in different regions of China.