Wastewater-based surveillance can be a valuable tool to monitor viral circulation and serve as an early warning system. For respiratory viruses that share similar clinical symptoms, namely SARS-CoV-2, influenza, syncytial virus (RSV), identification in wastewater may allow differentiation between seasonal outbreaks COVID-19 peaks. In this study, these well standard indicators of fecal contamination, weekly sampling campaign was carried out for 15 months (from September 2021 November 2022)...

The different mechanisms of Klebsiella pneumoniae resistance to complement-mediated killing were investigated by using strains and isogenic mutants previously characterized for their surface components. We found that from serotypes whose K antigen masks the lipopolysaccharide (LPS) molecules (such as K1, K10, K16) fail activate complement, while with smooth LPS exposed at cell (with or without antigen) complement but are resistant killing. reasons this C3b binds far membrane lytic final...

Summary Mesophilic Aeromonas strains express a single polar flagellum in all culture conditions and produce lateral flagella on solid media. Such hyperflagellated cells demonstrate increased adherence. Nine genes, lafA–U for hydrophila , four caviae lafA1 lafA2 lafB fliU were isolated. Mutant characterization, nucleotide N‐terminal sequencing demonstrated that the A. flagellins almost identical, but distinct from their counterparts. The aeromonad exhibited higher molecular masses SDS–PAGE,...

Aeromonas hydrophila is a gram-negative opportunistic pathogen in fish and humans. Many bacterial pathogens of animals plants have been shown to inject anti-host virulence determinants into the hosts via type III secretion system (TTSS). Degenerate primers based on lcrD family genes that are present every known TTSS allowed us locate gene cluster A. AH-1. A series genome walking steps helped identification 25 open reading frames encode proteins homologous those TTSSs other bacteria....

The mechanisms of killing Klebsiella pneumoniae serum-sensitive strains in nonimmune serum by the complement classical pathway have been studied. bacterial cell surface components that bind C1q more efficiently were identified as two major outer membrane proteins, presumably porins this species. These proteins isolated from a representative strain. We demonstrated their purified form, they and activate an antibody-independent manner, with subsequent consumption C4 reduction total hemolytic...

ABSTRACT We have previously described an inhibition enzyme-linked immunosorbent assay method for the O typing of O1 lipopolysaccharide from Klebsiella pneumoniae which overcomes technical problems and limitations classical O-typing method. In this study, we extended to all currently recognized types. The was validated by studying prototype strains that defined groups tube agglutinatination Based on these results, confirmed types 60 64 typeable strains, propose a revised O-antigenic scheme,...

Summary This study presents an easy protocol to measure the amount of immunoglobulins from blood serum different bird species in wild ( Ficedula hypoleuca Pallas, Parus caeruleus L., Lanius meridionalis Temminkck, collurio Athene noctua Scopoli and Falco tinnunculus L.) by direct enzyme‐linked immunosorbent assay, ELISA using commercial antichicken antibodies. Additionally, technique is validated for detecting means other electrophoretic (sodium dodecyl sulphate polyacrylamide gel...

A cosmid-based genomic library of Serratia marcescens N28b was introduced into Escherichia coli DH5alpha, and clones were screened for serum resistance. One clone found resistant to serum, bacteriocin 28b, bacteriophages TuIa TuIb. This also showed O antigen in its lipopolysaccharide. Subcloning sequencing experiments that a 2,124-bp DNA fragment containing the rmlD wbbL genes responsible observed phenotypes. On basis amino acid similarity, we suggest 288-residue RmlD protein is...

ABSTRACT We have previously demonstrated the existence of Klebsiella pneumoniae clinical isolates deficient in lipopolysaccharide O side chain, major factor for resistance to complement-mediated killing this bacterial species. These are complement resistant, and their mechanisms resist were investigated by selecting transposon-generated complement-sensitive mutants. One mutant with a drastically reduced capacity grow nonimmune human serum carried transposon inserted an open reading frame...

ABSTRACT Aeromonas hydrophila is a gram-negative opportunistic pathogen of animals and humans. The pathogenesis A. multifactorial. Genomic subtraction markers genomic islands (GIs) were used to identify putative virulence genes in PPD134/91. Two rounds led the identification 22 unique DNA fragments encoding 19 factors seven new open reading frames, which are commonly present eight strains examined. In addition, four GIs found, including O-antigen, capsule, phage-associated, type III...

ABSTRACT Two different representative recombinant clones encoding Aeromonas hydrophila lipases were found upon screening on tributyrin (phospholipase A1) and egg yolk agar (lecithinase-phospholipase C) plates of a cosmid-based genomic library AH-3 (serogroup O34) introduced into Escherichia coli DH5α. Subcloning, nucleotide sequencing, in vitro-coupled transcription-translation experiments showed that the phospholipase A1 ( pla ) C plc genes code for an 83-kDa putative lipoprotein 65-kDa...

Klebsiella pneumoniae strains typically express both smooth lipopolysaccharide (LPS) with O antigen molecules and capsule polysaccharide (K antigen) on the surface. A single mutation in a gene that codes for UDP galacturonate 4-epimerase (uge) renders strain O-:K- phenotype (lack of LPS without outer core oligosaccharide). The uge was present all K. tested. mutants were unable to produce experimental urinary tract infections rats completely avirulent two different animal models (septicemia...

Two types of flagella are responsible for motility in mesophilic Aeromonas strains. A polar unsheathed flagellum is expressed constitutively that allows the bacterium to swim liquid environments and, media where unable propel cell, express peritrichous lateral flagella. Recently, Southern blot analysis using a DNA probe based on caviae Sch3N flagellin gene sequence showed good correlation between strains positive probe, swarming and presence by microscopy. Here, we conclude easiest method...

ABSTRACT To determine the function of wabG gene in biosynthesis core lipopolysaccharide (LPS) Klebsiella pneumoniae , we constructed nonpolar mutants. Data obtained from comparative chemical and structural analysis LPS samples wild type, mutant strain, complemented demonstrated that is involved attachment toα - l -glycero- d -manno-heptopyranose II ( -Hep p II) at O-3 position anα -galactopyranosyluronic acid (α- -GalA ) residue. K. mutants were devoid cell-attached capsular polysaccharide...

ABSTRACT Mesophilic Aeromonas spp. constitutively express a single polar flagellum that helps the bacteria move to more favorable environments and is an important virulence colonization factor. Certain strains can also produce multiple lateral flagella in semisolid media or over surfaces. We have previously reported 16 genes ( flgN flgL ) constitute region 1 of hydrophila AH-3 biogenesis gene clusters. identified 39 new distributed four noncontiguous chromosome regions (regions 2 5). Region...

We have investigated the existence and genetic organization of a functional type III secretion system (TTSS) in mesophilic Aeromonas strain by initially using hydrophila AH-3. report for first time complete TTSS DNA sequence an that comprises 35 genes organized similar disposition as Pseudomonas aeruginosa. Using several gene probes, we also determined presence clinical or environmental strains different species: A. hydrophila, veronii, caviae. By one (ascV), were able to obtain defined...

ABSTRACT Mesophilic Aeromonas strains express a polar flagellum in all culture conditions, and certain produce lateral flagella on semisolid media or surfaces. Although have been described as colonization factor, little is known about their organization expression. Here we characterized the complete flagellar gene cluster of hydrophila AH-3 containing 38 genes, 9 which ( lafA-U ) reported previously. Among flgL L lafA structural genes found modification accessory factor maf-5 that involved...

We compared the ability of Aeromonas hydrophila wild-type strains serogroup O:34, non-motile Tn5 aflagellar mutants and same harboring a recombinant cosmid DNA from library A. AH-3 (O:34, wild-type) that allows these to make flagella be motile, adhere invade two fish cell lines. found motility is essential in for adhesion, also possession cannot rule out may an adhesin, or involved O:34 bacterial invasion both

The majority of Klebsiella pneumoniae serum-resistant strains activate complement and bind C3b, the opsonic fragment C3, without C5b-9 formation bacterial killing. mechanisms leading to C3b deposition cell death were studied, results indicate that principally alternative pathway serum-sensitive both classical pathways. Bacterial molecules implicated in are outer membrane porin proteins smooth rough lipopolysaccharides. Porins pathways, lipopolysaccharide activates pathway, causing strains....