Hemoptysis caused by Parvimonas micra: case report and literature review.

Background: Parvimonas micra (P. micra), a Gram-positive anaerobic bacterium, exhibits colonization tendencies on oral mucosal and skin surfaces, potentially evolving into a pathogenic entity associated with diverse diseases. The diagnostic trajectory for P. micra-related diseases encounters delays, often with severe consequences, including fatality, attributed to the absence of symptom specificity and challenges in culture. The absence of a consensus on the diagnostic and therapeutic approaches to P. micra exacerbates the complexity of addressing associated conditions. This study aims to elucidate and scrutinize the clinical manifestations linked to P. micra, drawing insights from an extensive literature review of pertinent case reports. Case presentation: A 53-year-old male sought medical attention at our institution presenting with recurrent hemoptysis. Empirical treatment was initiated while awaiting pathogen culture results; however, the patient's symptoms persisted. Subsequent metagenomic next-generation sequencing (mNGS) analysis revealed a pulmonary infection attributable to P. micra. Resolution of symptoms occurred following treatment with piperacillin sulbactam sodium and moxifloxacin hydrochloride. A comprehensive literature review, utilizing the PubMed database, was conducted to assess case reports over the last decade where P. micra was identified as the causative agent. Conclusion: The literature analysis underscores the predilection of P. micra for immunocompromised populations afflicted by cardiovascular diseases, diabetes, orthopedic conditions, and tumors. Risk factors, including oral and periodontal hygiene, smoking, and alcohol consumption, were found to be associated with P. micra infections. Clinical manifestations encompassed fever, cough, sputum production, and back pain, potentially leading to severe outcomes such as Spondylodiscitis, septic arthritis, lung abscess, bacteremia, sepsis, and mortality. While conventional bacterial culture remains the primary diagnostic tool, emerging technologies like mNGS offer alternative considerations. In terms of treatment modalities, ß-lactam antibiotics and nitroimidazoles predominated, exhibiting recovery rates of 56.10% (46/82) and 23.17% (19/82), respectively. This case report and literature review collectively aim to enhance awareness among clinicians and laboratory medicine professionals regarding the intricacies of P. micra-associated infections.

Comparison of fast Fourier transform infrared spectroscopy biotyping with whole genome sequencing-based genotyping in common nosocomial pathogens.

Early detection of bacterial transmission and outbreaks in hospitals is important because nosocomial infections can result in health complications and longer hospitalization. Current practice to detect outbreaks uses genotyping methods amplified fragment length polymorphism (AFLP) and whole genome sequencing (WGS), which are not suitable methods for real-time transmission screening of both susceptible and resistant bacteria. The aim was to assess the typing technique Fourier transform infrared (FTIR) spectroscopy as real-time screening method to discriminate large amounts of susceptible and resistant bacteria at strain level when there is no evident outbreak in comparison with the WGS reference. Isolates of past hospital outbreak strains of Acinetobacter baumannii/calcoaceticus complex (n = 25), Escherichia coli (n = 31), Enterococcus faecium (n = 22), Staphylococcus aureus (n = 37) and Pseudomonas aeruginosa (n = 30) were used for validation of FTIR. Subsequently, Enterococcus faecalis (n = 106) and Enterococcus faecium (n = 104) isolates from weekly routine screening samples when no potential outbreak was present were analysed. FTIR showed reproducibility and congruence of cluster composition with WGS for A. baumannii/calcoaceticus complex and E. faecium outbreak isolates. The FTIR results of E. faecalis and E. faecium isolates from routine samples showed reproducibility, but the congruence of cluster composition with WGS was low. For A. baumannii/calcoaceticus complex and E. faecium outbreak isolates, FTIR appears to be a discriminatory typing tool. However, our study shows the discriminatory power is too low to screen real-time for transmission of E. faecium and E. faecalis at patient wards based on isolates acquired in routine surveillance cultures when there is no clear suspicion of an ongoing outbreak.

CRIg on liver macrophages clears pathobionts and protects against alcoholic liver disease.

Complement receptor of immunoglobulin superfamily (CRIg) is expressed on liver macrophages and directly binds complement component C3b or Gram-positive bacteria to mediate phagocytosis. CRIg plays important roles in several immune-mediated diseases, but it is not clear how its pathogen recognition and phagocytic functions maintain homeostasis and prevent disease. We previously associated cytolysin-positive Enterococcus faecalis with severity of alcohol-related liver disease. Here, we demonstrate that CRIg is reduced in liver tissues from patients with alcohol-related liver disease. CRIg-deficient mice developed more severe ethanol-induced liver disease than wild-type mice; disease severity was reduced with loss of toll-like receptor 2. CRIg-deficient mice were less efficient than wild-type mice at clearing Gram-positive bacteria such as Enterococcus faecalis that had translocated from gut to liver. Administration of the soluble extracellular domain CRIg-Ig protein protected mice from ethanol-induced steatohepatitis. Our findings indicate that ethanol impairs hepatic clearance of translocated pathobionts, via decreased hepatic CRIg, which facilitates progression of liver disease.

Lumpfish (Cyclopterus lumpus) Is Susceptible to Renibacterium salmoninarum Infection and Induces Cell-Mediated Immunity in the Chronic Stage.

Renibacterium salmoninarum is a Gram-positive, intracellular pathogen that causes Bacterial Kidney Disease (BKD) in several fish species in freshwater and seawater. Lumpfish (Cyclopterus lumpus) is utilized as a cleaner fish to biocontrol sea lice infestation in Atlantic salmon (Salmo salar) farms. Atlantic salmon is susceptible to R. salmoninarum, and it can transfer the infection to other fish species. Although BKD outbreaks have not been reported in lumpfish, its susceptibility and immune response to R. salmoninarum is unknown. In this study, we evaluated the susceptibility and immune response of lumpfish to R. salmoninarum infection. Groups of lumpfish were intraperitoneally (i.p.) injected with either R. salmoninarum (1×107, 1×108, or 1×109 cells dose-1) or PBS (control). R. salmoninarum infection kinetics and mortality were followed for 98 days post-infection (dpi). Transcript expression levels of 33 immune-relevant genes were measured in head kidney (n = 6) of fish infected with 1×109 cells/dose and compared to the control at 28 and 98 dpi. Infected lumpfish displayed characteristic clinical signs of BKD. Lumpfish infected with high, medium, and low doses had a survival rate of 65%, 93%, and 95%, respectively. Mortality in the high-dose infected group stabilized after 50 dpi, but R. salmoninarum persisted in the fish tissues until 98 dpi. Cytokines (il1ß, il8a, il8b), pattern recognition receptors (tlr5a), interferon-induced effectors (rsad2, mxa, mxb, mxc), and iron regulation (hamp) and acute phase reactant (saa5) related genes were up-regulated at 28 dpi. In contrast, cell-mediated adaptive immunity-related genes (cd4a, cd4b, ly6g6f, cd8a, cd74) were down-regulated at 28 dpi, revealing the immune suppressive nature of R. salmoninarum. However, significant upregulation of cd74 at 98 dpi suggests induction of cell-mediated immune response. This study showed that R. salmoninarum infected lumpfish in a similar fashion to salmonid fish species and caused a chronic infection, enhancing cell-mediated adaptive immune response.

Clavibacter michiganensis Downregulates Photosynthesis and Modifies Monolignols Metabolism Revealing a Crosstalk with Tomato Immune Responses.

The gram-positive pathogenic bacterium Clavibacter michiganensis subsp. michiganensis (Cmm) causes bacterial canker disease in tomato, affecting crop yield and fruit quality. To understand how tomato plants respond, the dynamic expression profile of host genes was analyzed upon Cmm infection. Symptoms of bacterial canker became evident from the third day. As the disease progressed, the bacterial population increased in planta, reaching the highest level at six days and remained constant till the twelfth day post inoculation. These two time points were selected for transcriptomics. A progressive down-regulation of key genes encoding for components of the photosynthetic apparatus was observed. Two temporally separated defense responses were observed, which were to an extent interdependent. During the primary response, genes of the phenylpropanoid pathway were diverted towards the synthesis of monolignols away from S-lignin. In dicots, lignin polymers mainly consist of G- and S-units, playing an important role in defense. The twist towards G-lignin enrichment is consistent with previous findings, highlighting a response to generate an early protective barrier and to achieve a tight interplay between lignin recomposition and the primary defense response mechanism. Upon progression of Cmm infection, the temporal deactivation of phenylpropanoids coincided with the upregulation of genes that belong in a secondary response mechanism, supporting an elegant reprogramming of the host transcriptome to establish a robust defense apparatus and suppress pathogen invasion. This high-throughput analysis reveals a dynamic reorganization of plant defense mechanisms upon bacterial infection to implement an array of barriers preventing pathogen invasion and spread.

Comprehensive Molecular Dissection of Dermatophilus congolensis Genome and First Observation of tet(Z) Tetracycline Resistance.

Dermatophilus congolensis is a bacterial pathogen mostly of ruminant livestock in the tropics/subtropics and certain temperate climate areas. It causes dermatophilosis, a skin disease that threatens food security by lowering animal productivity and compromising animal health and welfare. Since it is a prevalent infection in ruminants, dermatophilosis warrants more research. There is limited understanding of its pathogenicity, and as such, there is no registered vaccine against D. congolensis. To better understanding the genomics of D. congolensis, the primary aim of this work was to investigate this bacterium using whole-genome sequencing and bioinformatic analysis. D. congolensis is a high GC member of the Actinobacteria and encodes approximately 2527 genes. It has an open pan-genome, contains many potential virulence factors, secondary metabolites and encodes at least 23 housekeeping genes associated with antimicrobial susceptibility mechanisms and some isolates have an acquired antimicrobial resistance gene. Our isolates contain a single CRISPR array Cas type IE with classical 8 Cas genes. Although the isolates originate from the same geographical location there is some genomic diversity among them. In conclusion, we present the first detailed genomic study on D. congolensis, including the first observation of tet(Z), a tetracycline resistance-conferring gene.

lncRNA-CR46018 positively regulates the Drosophila Toll immune response by interacting with Dif/Dorsal.

The Toll signaling pathway is highly conserved from insects to mammals. Drosophila is a model species that is commonly used to study innate immunity. Although many studies have assessed protein-coding genes that regulate the Toll pathway, it is unclear whether long noncoding RNAs (lncRNAs) play regulatory roles in the Toll pathway. Here, we evaluated the expression of the lncRNA CR46018 in Drosophila. Our results showed that this lncRNA was significantly overexpressed after infection of Drosophila with Micrococcus luteus. A CR46018-overexpressing Drosophila strain was then constructed; we expected that CR46018 overexpression would enhance the expression of various antimicrobial peptides downstream of the Toll pathway, regardless of infection with M. luteus. RNA-seq analysis of CR46018-overexpressing Drosophila after infection with M. luteus showed that upregulated genes were mainly enriched in Toll and Imd signaling pathways. Moreover, bioinformatics predictions and RNA-immunoprecipitation experiments showed that CR46018 interacted with the transcription factors Dif and Dorsal to enhance the Toll pathway. During gram-positive bacterial infection, flies overexpressing CR46018 showed favorable survival compared with flies in the control group. Overall, our current work not only reveals a new immune regulatory factor, lncRNA-CR46018, and explores its potential regulatory model, but also provides a new perspective for the effect of immune disorders on the survival of Drosophila melanogaster.

Lactobacillus rhamnosus GG modifies the metabolome of pathobionts in gnotobiotic mice.

BACKGROUND: Lactobacillus rhamnosus GG (LGG) is the most widely used probiotic, but the mechanisms underlying its beneficial effects remain unresolved. Previous studies typically inoculated LGG in hosts with established gut microbiota, limiting the understanding of specific impacts of LGG on host due to numerous interactions among LGG, commensal microbes, and the host. There has been a scarcity of studies that used gnotobiotic animals to elucidate LGG-host interaction, in particular for gaining specific insights about how it modifies the metabolome. To evaluate whether LGG affects the metabolite output of pathobionts, we inoculated with LGG gnotobiotic mice containing Propionibacterium acnes, Turicibacter sanguinis, and Staphylococcus aureus (PTS). RESULTS: 16S rRNA sequencing of fecal samples by Ion Torrent and MinION platforms showed colonization of germ-free mice by PTS or by PTS plus LGG (LTS). Although the body weights and feeding rates of mice remained similar between PTS and LTS groups, co-associating LGG with PTS led to a pronounced reduction in abundance of P. acnes in the gut. Addition of LGG or its secretome inhibited P. acnes growth in culture. After optimizing procedures for fecal metabolite extraction and metabolomic liquid chromatography-mass spectrometry analysis, unsupervised and supervised multivariate analyses revealed a distinct separation among fecal metabolites of PTS, LTS, and germ-free groups. Variables-important-in-projection scores showed that LGG colonization robustly diminished guanine, ornitihine, and sorbitol while significantly elevating acetylated amino acids, ribitol, indolelactic acid, and histamine. In addition, carnitine, betaine, and glutamate increased while thymidine, quinic acid and biotin were reduced in both PTS and LTS groups. Furthermore, LGG association reduced intestinal mucosal expression levels of inflammatory cytokines, such as IL-1α, IL-1ß and TNF-α. CONCLUSIONS: LGG co-association had a negative impact on colonization of P. acnes, and markedly altered the metabolic output and inflammatory response elicited by pathobionts.

PRAK Promotes the Pathogen Clearance by Macrophage Through Regulating Autophagy and Inflammasome Activation.

The p38 regulated/activated protein kinase (PRAK) is a protein kinase downstream of p38MAPK. The present study investigated its function in the macrophage. Myeloid-specific deletion of Prak resulted in a significant reduction in F4/80+CD11b+ peritoneal macrophages with decreased expression of MHC-II and CD80. Upon infection with Listeria monocytogenes, Prak-deficient mice demonstrated an increased mortality, which was accompanied by a higher bacterial load in multiple tissues and elevated levels of proinflammatory cytokines in the serum. While the Prak-deficient macrophage showed similar potency in phagocytosis assays, its bactericidal activity was severely impaired. Moreover, Prak deficiency was associated with defects in ROS production, inflammasome activation as well as autophagy induction. Therefore, PRAK critically contributes to the clearance of intracellular pathogens by affecting multiple aspects of the macrophage function.

ddcP, pstB, and excess D-lactate impact synergism between vancomycin and chlorhexidine against Enterococcus faecium 1,231,410.

Vancomycin-resistant enterococci (VRE) are important nosocomial pathogens that cause life-threatening infections. To control hospital-associated infections, skin antisepsis and bathing utilizing chlorhexidine is recommended for VRE patients in acute care hospitals. Previously, we reported that exposure to inhibitory chlorhexidine levels induced the expression of vancomycin resistance genes in VanA-type Enterococcus faecium. However, vancomycin susceptibility actually increased for VanA-type E. faecium in the presence of chlorhexidine. Hence, a synergistic effect of the two antimicrobials was observed. In this study, we used multiple approaches to investigate the mechanism of synergism between chlorhexidine and vancomycin in the VanA-type VRE strain E. faecium 1,231,410. We generated clean deletions of 7 of 11 pbp, transpeptidase, and carboxypeptidase genes in this strain (ponA, pbpF, pbpZ, pbpA, ddcP, ldtfm, and vanY). Deletion of ddcP, encoding a membrane-bound carboxypeptidase, altered the synergism phenotype. Furthermore, using in vitro evolution, we isolated a spontaneous synergy escaper mutant and utilized whole genome sequencing to determine that a mutation in pstB, encoding an ATPase of phosphate-specific transporters, also altered synergism. Finally, addition of excess D-lactate, but not D-alanine, enhanced synergism to reduce vancomycin MIC levels. Overall, our work identified factors that alter chlorhexidine and vancomycin synergism in a model VanA-type VRE strain.

A transcriptomic analysis of sugarcane response to Leifsonia xyli subsp. xyli infection.

Sugarcane ratoon stunting disease (RSD) caused by Leifsonia xyli subsp. xyli (Lxx) is a common destructive disease that occurs around the world. Lxx is an obligate pathogen of sugarcane, and previous studies have reported some physiological responses of RSD-affected sugarcane. However, the molecular understanding of sugarcane response to Lxx infection remains unclear. In the present study, transcriptomes of healthy and Lxx-infected sugarcane stalks and leaves were studied to gain more insights into the gene activity in sugarcane in response to Lxx infection. RNA-Seq analysis of healthy and diseased plants transcriptomes identified 107,750 unigenes. Analysis of these unigenes showed a large number of differentially expressed genes (DEGs) occurring mostly in leaves of infected plants. Sugarcane responds to Lxx infection mainly via alteration of metabolic pathways such as photosynthesis, phytohormone biosynthesis, phytohormone action-mediated regulation, and plant-pathogen interactions. It was also found that cell wall defense pathways and protein phosphorylation/dephosphorylation pathways may play important roles in Lxx pathogeneis. In Lxx-infected plants, significant inhibition in photosynthetic processes through large number of differentially expressed genes involved in energy capture, energy metabolism and chloroplast structure. Also, Lxx infection caused down-regulation of gibberellin response through an increased activity of DELLA and down-regulation of GID1 proteins. This alteration in gibberellic acid response combined with the inhibition of photosynthetic processes may account for the majority of growth retardation occurring in RSD-affected plants. A number of genes associated with plant-pathogen interactions were also differentially expressed in Lxx-infected plants. These include those involved in secondary metabolite biosynthesis, protein phosphorylation/dephosphorylation, cell wall biosynthesis, and phagosomes, implicating an active defense response to Lxx infection. Considering the fact that RSD occurs worldwide and a significant cause of sugarcane productivity, a better understanding of Lxx resistance-related processes may help develop tools and technologies for producing RSD-resistant sugarcane varieties through conventional and/or molecular breeding.

Bactericidal activity of a substituted thiazole against multidrug-resistant Eggerthia catenaformis isolated from patients with dental abscess.

Human infections caused by the anaerobic bacterium Eggerthia catenaformis are rare. However, a growing number of case reports have presented the bacterium as the causative agent in many serious complications. This study provides data on the isolation and antibiotic susceptibility profiles of E. catenaformis from dental abscess. Identification of isolates was performed using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). We also investigated the antibacterial activity of 5-acetyl-4-methyl-2-(3-pyridyl) thiazole (AMPT) on E. catenaformis isolates. Minimum inhibitory concentrations (MICs) were determined by an agar dilution method and bactericidal activity was evaluated by a time-kill assay. Moreover, the mechanism of action of AMPT was also explored by cell membrane disruption assay and scanning electron microscopy (SEM). MALDI-TOF MS results revealed unambiguous identification of all isolates with score values between 2.120 and 2.501. Isolates NY4 and NY9 (20% of isolates) were found resistant to multiple antibiotics judged by MIC values. As multidrug-resistant strains of E. catenaformis were not reported to date, we then confirmed the identity of NY4 and NY9 based on 16S rRNA gene sequence. Favorably, all isolates were susceptible to AMPT with an MIC range of 0.25-1 mg/L. Time-kill kinetics of AMPT indicated that it exhibited potent bactericidal activity against the multidrug-resistant isolates NY4 and NY9. Furthermore, this study also hypothesizes that AMPT exerts its antibacterial effect through damaging the cell membrane and thereby induce the release of intracellular components. AMPT could therefore be considered as a therapeutic option for infections caused by multidrug-resistant bacteria.

Phage infection and sub-lethal antibiotic exposure mediate Enterococcus faecalis type VII secretion system dependent inhibition of bystander bacteria.

Bacteriophages (phages) are being considered as alternative therapeutics for the treatment of multidrug resistant bacterial infections. Considering phages have narrow host-ranges, it is generally accepted that therapeutic phages will have a marginal impact on non-target bacteria. We have discovered that lytic phage infection induces transcription of type VIIb secretion system (T7SS) genes in the pathobiont Enterococcus faecalis. Membrane damage during phage infection induces T7SS gene expression resulting in cell contact dependent antagonism of different Gram positive bystander bacteria. Deletion of essB, a T7SS structural component, abrogates phage-mediated killing of bystanders. A predicted immunity gene confers protection against T7SS mediated inhibition, and disruption of its upstream LXG toxin gene rescues growth of E. faecalis and Staphylococcus aureus bystanders. Phage induction of T7SS gene expression and bystander inhibition requires IreK, a serine/threonine kinase, and OG1RF_11099, a predicted GntR-family transcription factor. Additionally, sub-lethal doses of membrane targeting and DNA damaging antibiotics activated T7SS expression independent of phage infection, triggering T7SS antibacterial activity against bystander bacteria. Our findings highlight how phage infection and antibiotic exposure of a target bacterium can affect non-target bystander bacteria and implies that therapies beyond antibiotics, such as phage therapy, could impose collateral damage to polymicrobial communities.

Therapeutic Options for Infections due to vanB Genotype Vancomycin-Resistant Enterococci.

Enterococci are ubiquitous, facultative, anaerobic Gram-positive bacteria that mainly reside, as part of the normal microbiota, in the gastrointestinal tracts of several animal species, including humans. These bacteria have the capability to turn from a normal gut commensal organism to an invasive pathogen in patients debilitated by prolonged hospitalization, concurrent illnesses, and/or exposed to broad-spectrum antibiotics. The majority of vancomycin-resistant enterococcus (VRE) infections are linked to the vanA genotype; however, outbreaks caused by vanB-type VREs have been increasingly reported, representing a new challenge for effective antimicrobial treatment. Teicoplanin, daptomycin, fosfomycin, and linezolid are useful antimicrobials for infections due to vanB enterococci. In addition, new drugs have been developed (e.g., dalbavancin, telavancin, and tedizolid), new molecules will soon be available (e.g., eravacycline, omadacycline, and oritavancin), and new treatment strategies are progressively being used in clinical practice (e.g., combination therapies and bacteriophages). The aim of this article is to discuss the pathogenesis of infections due to enterococci harboring the vanB operon (vanBVRE) and their therapeutic, state-of-the-art, and future treatment options and provide a comprehensive and easy to use review for clinical purposes.

Spectrum of Bacterial Colonization in Patients Hospitalized for Treatment of Multidrug-Resistant Tuberculosis.

This study investigated the bacterial colonization in patients admitted for treatment of drug-resistant tuberculosis in a specialized TB hospital. Identification and antimicrobial susceptibility testing of bacterial isolates (n = 62) from nasal, groin, and rectal swabs [patient cohort (n = 37)] were determined by the VITEK-MS system. Resistance gene analysis was by PCR and DNA sequencing. Molecular typing of Klebsiella pneumoniae isolates was by Multilocus Sequencing Typing (MLST). Patients (n = 13/37; 35%) were colonized by multidrug-resistant (MDR) bacteria (ESBL and MRSA) on admission. Of the 24 patients who were not colonized by MDR bacteria on admission, 46% (17/37) became colonized by MDR bacteria within 1 month of admission, mostly with ESBL-producing Enterobacteriales and resistance to aminoglycosides and fluoroquinolones. ESBL Escherichia coli (41/62; 66%) and K. pneumoniae (14/62; 23%) predominated. Genes encoding for ESBLs (blaCTX-M-14, blaCTX-M-15, blaSHV-28, blaOXA-1, and blaOXY-2) and plasmid-mediated quinolone resistant genes (qnrB1, qnrB4, and qnrB10) were detected. MLST revealed genetic diversity among the K. pneumoniae isolates from hospitalized patients. This study provides insight into bacterial pathogen colonization in hospitalized TB patients with the first occurrence of the qnrB4 and qnrB10 genes and co-expression of genes: qnrB4+aac(6')-lb-cr, qnrB10+aac(6')-lb-cr, qnrB4+qnrS1, and qnrB10+qnrS1 in fluoroquinolone-resistant E. coli isolates within South Africa. However, the source and colonization routes of these isolates could not be determined.

Penicillin-Resistant, Ampicillin-Susceptible Enterococcus faecalis in Polish Hospitals.

The objective of this study was to characterize Polish penicillin-resistant, ampicillin-susceptible Enterococcus faecalis (PRASEF), increasingly reported to the National Reference Centre for Susceptibility Testing, Poland, to elucidate the path of emergence of such strains. A total of 136 isolates were examined by antimicrobial susceptibility testing and for the ß-lactamase production (cefinase test). The clonality of isolates was established by multilocus sequence typing (MLST) and the penicillin-binding protein pbp4 gene was sequenced to search for putative mutation(s). The presence of pheromone-responsive plasmids was investigated by clumping test and PCR detection of plasmid-specific genes. All Polish PRASEF were multidrug resistant and ß-lactamase-negative. MLST assigned isolates mostly to high-risk enterococcal clonal complexes (HIRECCs) 6 (57.4%) and 87 (30.1%), in addition to to CC88 (12.5%). The sequencing of pbp4 revealed mutations upstream of a putative promoter region and amino acid alterations in PBP4, affecting 24 positions and resulting in 30 variants. While production of aggregation substance was observed for 17.6% of isolates, genes of pheromone plasmids were much more commonly detected. However, no conjugal transfer of penicillin resistance was observed. Penicillin resistance in E. faecalis emerges mostly in HiRECCs due to PBP4 overproduction and/or mutations. The acquisition of penicillin resistance by HiRECCs may represent the next step in the evolution of E. faecalis as human nosocomial pathogen.

Emergence of high-risk multidrug-resistant Enterococcus faecalis CC2 (ST181) and CC87 (ST28) causing healthcare-associated infections in India.

High-risk hospital-associated multidrug-resistant (MDR) Enterococcus faecalis clonal complexes (CCs) such as CC2 and CC87 are enriched with virulence determinants that help to accumulate, colonize, and cause serious nosocomial infections. The aim of this study was to establish the epidemiology and clonal composition of 134 clinical E. faecalis isolates and to link molecular typing data with antimicrobial resistance and virulence determinants. All isolates were identified by conventional methods and confirmed by polymerase chain reaction (PCR) (16srRNA gene and ddl genes of E. faecalis/ E. faecium) in 5-years. Disc diffusion test was performed on all strains. We screened all E. faecalis for aac(6')-aph(2″), vanA, and vanB resistance genes, and aggregation substance-asa1, cytolysin-cylA, collagen-binding protein-ace, enterococcal surface protein-esp, gelatinase-gelE, and hyaluronidase-hyl virulence genes by PCR. Representative isolates of E. faecalis were characterized by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). Out of 539 patients with enterococcal infections, 134 (24.9%) had E. faecalis infections, 366 (67.9%) had E. faecium infections, and 39 (7.2%) had infections due to other enterococcal species. Of the 134 isolates, 79.1% and 61.9% isolates were high-level gentamicin resistant (HLGR) and MDR. In multivariate analysis, independent predictor for infection due to MDR E. faecalis strains was a surgical intervention (OR 2.41, 95% CI 1.17-4.96, P = 0·017). Overall, the observed rate of in-hospital mortality was 11.9%. The gelE, asa1, ace, cylA, esp and hyl genes were detected in 87.3%, 78.4%, 54.5%, 53.7%, 36.6% and 3.0%, respectively in E. faecalis isolates. The asaI, cylA, and gelE genes were significantly correlated with MDR E. faecalis. The PFGE analysis showed 28 clones with four major clones. MLST analysis revealed two sequence types-ST28 (CC87) and ST181 (CC2). This is the first Indian report on the emergence of the high-risk hospital-associated worldwide-disseminated ST28 (CC87) and ST181 (CC2), which have enriched with multiple virulence determinants and resistance to antibiotics, paticularly ampicillin. This report indicates serious health concern and calls for on-going surveillance, close monitoring, and improved infection control procedures to stop further spread of these isolates.

Bacteria-induced IMD-Relish-AMPs pathway activation in Chinese mitten crab.

The innate immune response is an important line of defense against invading pathogens in invertebrates. Signaling pathways, including the IMD pathway, play critical roles in the production of antimicrobial peptides (AMPs), which induce the transcription of immune effectors that protect against bacterial invasion. In the present study, the cDNA of IMD from Eriocheir sinensis was cloned (designated EsIMD) and shown to be significantly upregulated following Gram-positive and Gram-negative bacterial infection. In vivo and in vitro studies collectively suggested that both the Gram-negative bacterium Vibrio parahemolyticus and the Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis elicit the translocation of Relish. Moreover, EsIMD positively regulated EsRelish translocation from the cytoplasm to the nucleus following stimulation with both Gram-positive and Gram-negative bacteria. EsRelish knockdown in hemocytes significantly suppressed AMPs' expression. Furthermore, both Lys-type and DAP-type peptidoglycan-containing bacteria activated the IMD pathway and elicited antibacterial responses in crab. Conclusively, these findings demonstrate that both Gram-positive and Gram-negative bacteria activate IMD signaling, via a mechanism that is distinct with that by which Gram-negative bacteria activate IMD signaling in Drosophila. These findings might pave the way for a better understanding of the innate immune system and the fundamental network of the IMD signaling pathway in crustacean.

Circular RNA PRKCI and microRNA-545 relate to sepsis risk, disease severity and 28-day mortality.

This study aimed to explore the clinical values of circular RNA protein kinase C iota (circ-PRKCI) and its target microRNA-545 (miR-545) in sepsis patients. Plasma samples of 121 sepsis patients and 60 healthy controls (HCs) were collected, then circ-PRKCI and miR-545 expressions were detected using RT-qPCR. Sepsis patients' demographics, biochemical indexes, medical histories, infection information were recorded. Besides, comprehensive disease scores (APACHE II score and SOFA score) were assessed within 24 h after admission. According to the survival status, 28-day mortality was calculated. Decreased circ-PRKCI expression and increased miR-545 expression were observed in sepsis patients compared to HCs, both of which had close correlations with sepsis risk. Besides, circ-PRKCI was negatively correlated with miR-545 in sepsis patients and HCs, respectively. Circ-PRKCI was negatively correlated with serum creatinine, white blood cell, C-reactive protein, APACHE II score, SOFA score, but positively correlated with albumin, which also related to blood stream infection (as primary infection site) and anaerobes infection in sepsis patients. Whereas the miR-545 showed a roughly opposite tendency. Decreased circ-PRKCI and increased miR-545 expressions were discovered in deaths compared to survivors, and both of them had values for predicting 28-day mortality risk in sepsis patients, which were slightly lower than the predictive values of APACHE II score and SOFA score for predicting 28-day mortality risk. Multivariate logistic analyses displayed circ-PRKCI as an independent factor predicting decreased 28-day mortality risk. In conclusion, circ-PRCKI insufficiency and miR-545 sufficiency were related to sepsis risk, clinical disease severity and 28-day mortality risk.

Exploring potential of vaginal Lactobacillus isolates from South African women for enhancing treatment for bacterial vaginosis.

Antibiotics continue to be the standard-of-care for bacterial vaginosis (BV), although recurrence rates are high. Vaginal probiotics may improve durability of BV treatment, although few probiotics for vaginal health contain Lactobacillus spp. that commonly colonize the lower female genital tract. Characteristics of vaginal Lactobacillus strains from South African women were evaluated for their probiotic potential in vitro compared to strains from commercial vaginal products, including growth at varying pHs, ability to lower pH, produce D-/L-lactate and H2O2, influence growth of BV-associated Gardnerella vaginalis and Prevotella bivia, adherence to cervical cells and susceptibility to antibiotics. Fifty-seven Lactobacillus strains were purified from cervico-vaginal fluid, including L. crispatus, L. jensenii, L. gasseri, L. mucosae, and L. vaginalis. L crispatus strains grew better at pHs below 4.5 and lowered pH more effectively than other strains. Production of D-/L-lactate and H2O2 varied between Lactobacillus species and strains. Lactobacillus strains generally inhibited P. bivia more uniformly than G. vaginalis isolates. All vaginal Lactobacillus isolates were resistant to metronidazole while susceptibility to clindamycin varied. Furthermore, vaginal Lactobacillus strains tended to be broadly susceptible to penicillin, amoxicillin, rifampicin and rifabutin. Whole-genome-sequencing of five of the best-performing vaginal Lactobacillus strains confirmed their likely safety, due to antimicrobial resistance elements being largely absent, while putative intact prophages were present in the genomes of two of the five strains. Overall, vaginal Lactobacillus strains largely performed better in these in vitro assays than probiotic strains currently used in probiotics for vaginal health. Including the best-performing vaginal Lactobacillus isolates in a region-specific probiotic for vaginal health may result in improved BV treatment options.