The importance of environments and surfaces hygienization in pandemic times (Covid-19): a microbiological analysis in places for physical activity practice

The objective of this study was to analyse microbiological organisms in different locations and regions for physical activity in the city of João Pessoa, Brazil. Samples were collected on various objects used, such as: mattresses, drinking fountains, gloves, cell phones and others. The samples were collected in João Pessoa-PB, following the Standard Operating Procedure-SOP/ Microbiology of a specialized laboratory. The collection took place in the five macro-regions: North, South, East, West and Center. Foreach region samples were collected in one public place (square), a private one (gym) and one school (public or private), totaling fifteen collected sites and 450 samples. The following microorganisms were studied in all analyzed surfaces: Bacillus sp, Escherichia Coli, Klebsiella sppor Enterobacter sppand Coag. Neg. Staphylococcus.All regions had a high contamination level by some microorganism. The highest rates were found in the western, central and northern regions -96, 94 and 93% respectively. The Coag. Neg.Staphylococcus presented the highest and lowest incidence rates in the South and East regions, with 43.33 and 6.67%, respectively, as well as Klebsiella sppor Enterobacter spp, which presented high levels. It is concluded that there is a microorganisms' contamination in the most varied places and regions where physical activity practices are developed, with a predominance of Coag. Neg.Staphylococcusand Klebsiella sppor Enterobacter spp. These results lead to a warning about the hygiene importance in places for physical activity practice, especially in pandemic times (COVID-19), since almost all the evaluated surfaces were contaminated.

Comparative genomics of Chinese and international isolates of Escherichia albertii: population structure and evolution of virulence and antimicrobial resistance.

Escherichia albertii is a recently recognized species in the genus Escherichia that causes diarrhoea. The population structure, genetic diversity and genomic features have not been fully examined. Here, 169 E. albertii isolates from different sources and regions in China were sequenced and combined with 312 publicly available genomes (from additional 14 countries) for genomic analyses. The E. albertii population was divided into two clades and eight lineages, with lineage 3 (L3), L5 and L8 more common in China. Clinical isolates were observed in all clades/lineages. Virulence genes were found to be distributed differently among lineages: subtypes of the intimin encoding gene eae and the cytolethal distending toxin gene cdtB were lineage associated, and the second type three secretion system (ETT2) island was truncated in L3 and L6. Seven new eae subtypes and one new cdtB subtype (cdtB-VI) were identified. Alarmingly, 85.9 % of the Chinese E. albertii isolates were predicted to be multidrug-resistant (MDR) with 35.9 % harbouring genes capable of conferring resistance to 10 to 14 different drug classes. The majority of the MDR isolates were of poultry source from China and belonged to four sequence types (STs) [ST4638, ST4479, ST4633 and ST4488]. Thirty-four plasmids with some carrying MDR and virulence genes, and 130 prophages were identified from 17 complete E. albertii genomes. The 130 intact prophages were clustered into five groups, with group five prophages harbouring more virulence genes. We further identified three E. albertii specific genes as markers for the identification of this species. Our findings provided fundamental insights into the population structure, virulence variation and drug resistance of E. albertii.

Mediation of the microbiome-gut axis by oyster (Crassostrea gigas) polysaccharides: A possible protective role in alcoholic liver injury.

The objective of this study was to evaluate the molecular mechanism by which polysaccharides from Crassostrea gigas (RPS) prevent alcoholic liver injury and to uncover whether the steaming process affects the bioactivities of RPS. Oral administration of RPS or polysaccharides from steamed oyster (SPS) (282 mg/kg b.w.) significantly attenuated alcoholic liver injury in mice. RPS and SPS treatments protected gut functions by significantly enhancing the expression of tight-junction proteins and suppressing inflammatory responses. RPS and SPS treatments also significantly increased Lactobacillus reuteri and Roseburia spp. and decreased the level of Escherichia. Microbial metabolites, especially propionate and butyrate, were also increased in RPS- and SPS-treated mice. Correlation analysis revealed that the beneficial effects of RPS and SPS were strongly correlated with the microbiota composition and SCFAs. These results indicated that oyster polysaccharides alleviated alcoholic liver injury by mediating the gut-liver-metabolite axis, and the steaming process had little influence on the bioactivity.

Attaching and effacing pathogens: the effector ABC of immune subversion.

The innate immune response resembles an essential barrier to bacterial infection. Many bacterial pathogens have, therefore, evolved mechanisms to evade from or subvert the host immune response in order to colonize, survive and multiply. The attaching and effacing pathogens enteropathogenic Escherichia coli, enterohaemorrhagic E. coli, Escherichia albertii and Citrobacter rodentium are Gram-negative extracellular gastrointestinal pathogens. They use a type III secretion system to inject effector proteins into the host cell to manipulate a variety of cellular processes. Over the last decade, considerable progress was made in identifying and characterizing the effector proteins of attaching and effacing pathogens that are involved in the inhibition of innate immune signaling pathways, in determining their host cell targets and elucidating the mechanisms they employ. Their functions will be reviewed here.

Escherichia albertii Pathogenesis.

Escherichia albertii is an emerging enteropathogen of humans and many avian species. This bacterium is a close relative of Escherichia coli and has been frequently misidentified as enteropathogenic or enterohemorrhagic E. coli due to their similarity in phenotypic and genetic features, such as various biochemical properties and the possession of a type III secretion system encoded by the locus of enterocyte effacement. This pathogen causes outbreaks of gastroenteritis, and some strains produce Shiga toxin. Although many genetic and phenotypic studies have been published and the genome sequences of more than 200 E. albertii strains are now available, the clinical significance of this species is not yet fully understood. The apparent zoonotic nature of the disease requires a deeper understanding of the transmission routes and mechanisms of E. albertii to develop effective measures to control its transmission and infection. Here, we review the current knowledge of the phylogenic relationship of E. albertii with other Escherichia species and the biochemical and genetic properties of E. albertii, with particular emphasis on the repertoire of virulence factors and the mechanisms of pathogenicity, and we hope this provides a basis for future studies of this important emerging enteropathogen.

Epidemiological Aspects of Escherichia albertii Outbreaks in Japan and Genetic Characteristics of the Causative Pathogen.

Zoonotic pathogen Escherichia albertii has been identified as the cause of several human disease outbreaks; however, factors such as the general symptoms and incubation period of E. albertii infection have yet to be defined. Therefore, we aimed to determine the unique aspects of E. albertii outbreaks in Japan and to examine the genetic characteristics of the causative pathogen. We studied all known E. albertii outbreaks that occurred in Japan up until 2015, which consisted of five confirmed outbreaks and one putative outbreak (Outbreaks 1-6). Outbreaks were re-examined based on personal communications between researchers in prefectural and municipal public health institutes, and through examination of any published study conducted at the time. Draft genome sequences of outbreak-associated E. albertii isolates were also generated. The most common symptom displayed by patients across the six episodes was watery diarrhea (>80%), followed by abdominal pain (50-84%) and fever (37.0-39.5°C) (26-44%). The estimated average incubation period of E. albertii infection was 12-24 h. We assumed that most of the outbreaks were foodborne or waterborne, with restaurant foods, restaurant water, and boxed lunches being the suspected transmission vehicles. Three of the six outbreak-associated E. albertii isolates possessed intact ETT2 regions, while the remaining isolates contained disrupted ETT2-encoding genes. Virulence gene screening revealed that more than half (44/70) of the tested genes were present in all 5 strains examined, and that each of the strains contained more than 1 gene from 14 out of the 21 groups of virulence genes examined in this study. The five E. albertii strains were classified into four of the five known phylogroups. Therefore, we determined that multiple E. albertii genotypes in Japan have the potential to cause outbreaks of diarrhea, abdominal pain, and/or fever following infection of a human host.

Posttraumatic stress disorder is associated with altered gut microbiota that modulates cognitive performance in veterans with cirrhosis.

Posttraumatic stress disorder (PTSD) is associated with cirrhosis in veterans, and therapeutic results are suboptimal. An altered gut-liver-brain axis exists in cirrhosis due to hepatic encephalopathy (HE), but the added impact of PTSD is unclear. The aim of this study was to define linkages between gut microbiota and cognition in cirrhosis with/without PTSD. Cirrhotic veterans (with/without prior HE) underwent cognitive testing [PHES, inhibitory control test (ICT), and block design test (BDT)], serum lipopolysaccharide-binding protein (LBP) and stool collection for 16S rRNA microbiota composition, and predicted function analysis (PiCRUST). PTSD was diagnosed using DSM-V criteria. Correlation networks between microbiota and cognition were created. Patients with/without PTSD and with/without HE were compared. Ninety-three combat-exposed male veterans [ (58 yr, MELD 11, 34% HE, 31% combat-PTSD (42 no-HE/PTSD, 19 PTSD-only, 22 HE-only, 10 PTSD+HE)] were included. PTSD patients had similar demographics, alcohol history, MELD, but worse ICT/BDT, and higher antidepressant use and LBP levels. Microbial diversity was lower in PTSD (2.1 ± 0.5 vs. 2.5 ± 0.5, P = 0.03) but unaffected by alcohol/antidepressant use. PTSD (P = 0.02) and MELD (P < 0.001) predicted diversity on regression. PTSD patients showed higher pathobionts (Enterococcus and Escherichia/Shigella) and lower autochthonous genera belonging to Lachnospiraceaeae and Ruminococcaceae regardless of HE. Enterococcus was correlated with poor cognition, while the opposite was true for autochthonous taxa regardless of PTSD/HE. Escherichia/Shigella was only linked with poor cognition in PTSD patients. Gut-brain axis-associated microbiota functionality was altered in PTSD. In male cirrhotic veterans, combat-related PTSD is associated with cognitive impairment, lower microbial diversity, higher pathobionts, and lower autochthonous taxa composition and altered gut-brain axis functionality compared with non-PTSD combat-exposed patients. Cognition was differentially linked to gut microbiota, which could represent a new therapeutic target.NEW & NOTEWORTHY Posttraumatic stress disorder (PTSD) in veterans with cirrhosis was associated with poor cognitive performance. This was associated with lower gut microbial diversity in PTSD with higher pathobionts belonging to Enterococcus and Escherichia/Shigella and lower beneficial taxa belonging to Lachnospiraceaeae and Ruminococcaceae, with functional alterations despite accounting for prior hepatic encephalopathy, psychoactive drug use, or model for end-stage liver disease score. Given the suboptimal response to current therapies for PTSD, targeting the gut microbiota could benefit the altered gut-brain axis in these patients.

Genomic and molecular characterisation of Escherichia marmotae from wild rodents in Qinghai-Tibet plateau as a potential pathogen.

Wildlife is a reservoir of emerging infectious diseases of humans and domestic animals. Marmota himalayana mainly resides 2800-4000 m above sea level in the Qinghai-Tibetan Plateau, and is the primary animal reservoir of plague pathogen Yersinia pestis. Recently we isolated a new species, Escherichia marmotae from the faeces of M. himalayana. In this study we characterised E. marmotae by genomic analysis and in vitro virulence testing to determine its potential as a human pathogen. We sequenced the genomes of the seven E. marmotae strains and found that they contained a plasmid that carried a Shigella-like type III secretion system (T3SS) and their effectors, and shared the same O antigen gene cluster as Shigella dysenterae 8 and E. coli O38. We also showed that E. marmotae was invasive to HEp-2 cells although it was much less invasive than Shigella. Thus E. marmotae is likely to be an invasive pathogen. However, E. marmotae has a truncated IpaA invasin, and lacks the environmental response regulator VirF and the IcsA-actin based intracellular motility, rendering it far less invasive in comparison to Shigella. E. marmotae also carried a diverse set of virulence factors in addition to the T3SS, including an IS1414 encoded enterotoxin gene astA with 37 copies, E. coli virulence genes lifA/efa, cif, and epeA, and the sfp gene cluster, Yersinia T3SS effector yopJ, one Type II secretion system and two Type VI secretion systems. Therefore, E. marmotae is a potential invasive pathogen.

Enterotype-based Analysis of Gut Microbiota along the Conventional Adenoma-Carcinoma Colorectal Cancer Pathway.

The dysbiosis of human gut microbiota is strongly associated with the development of colorectal cancer (CRC). The dysbiotic features of the transition from advanced polyp to early-stage CRC are largely unknown. We performed a 16S rRNA gene sequencing and enterotype-based gut microbiota analysis study. In addition to Bacteroides- and Prevotella-dominated enterotypes, we identified an Escherichia-dominated enterotype. We found that the dysbiotic features of CRC were dissimilar in overall samples and especially Escherichia-dominated enterotype. Besides a higher abundance of Fusobacterium, Enterococcus, and Aeromonas in all CRC faecal microbiota, we found that the most notable characteristic of CRC faecal microbiota was a decreased abundance of potential beneficial butyrate-producing bacteria. Notably, Oscillospira was depleted in the transition from advanced adenoma to stage 0 CRC, whereas Haemophilus was depleted in the transition from stage 0 to early-stage CRC. We further identified 7 different CAGs by analysing bacterial clusters. The abundance of microbiota in cluster 3 significantly increased in the CRC group, whereas that of cluster 5 decreased. The abundance of both cluster 5 and cluster 7 decreased in the Escherichia-dominated enterotype of the CRC group. We present the first enterotype-based faecal microbiota analysis. The gut microbiota of colorectal neoplasms can be influenced by its enterotype.

Phenotypic characterization and virulence-related properties of Escherichia albertii strains isolated from children with diarrhea in Brazil.

Escherichia albertii are emerging enteropathogens, whose identification is difficult, as they share biochemical characteristics and some virulence-related genes with diarrheagenic Escherichia coli (DEC). Studies on phylogeny, phenotypic characteristics and potential virulence factors of human E. albertii strains are scarce. In this study, we identified by multiplex PCR five E. albertii among 106 strains isolated from diarrheic children in São Paulo, Brazil, which were previously classified as atypical enteropathogenic E. coli. All strains were investigated regarding their phylogeny, biochemical properties, virulence-related properties, antimicrobial resistance and presence of putative virulence-related genes. All strains belonged to different E. albertii lineages and adhered to and produced attaching and effacing lesions on HeLa cells. Three strains invaded Caco-2 cells, but did not persist intracellularly, and three formed biofilms on polystyrene surfaces. All strains were resistant to few antibiotics and only one carried a self-transmissible resistance plasmid. Finally, among 38 DEC and 18 extraintestinal pathogenic E. coli (ExPEC) virulence-related genes searched, six and three were detected, respectively, with paa and cdtB being found in all strains. Despite the limited number of strains, this study provided additional knowledge on human E. albertii virulence potential, showing that they share important virulence factors with DEC and ExPEC.

The Evasive Enemy: Insights into the Virulence and Epidemiology of the Emerging Attaching and Effacing Pathogen Escherichia albertii.

The diarrheic attaching and effacing (A/E) pathogen Escherichia albertii was first isolated from infants in Bangladesh in 1991, although the bacterium was initially classified as Hafnia alvei Subsequent genetic and biochemical interrogation of these isolates raised concerns about their initial taxonomic placement. It was not until 2003 that these isolates were reassigned to the novel taxon Escherichia albertii because they were genetically more closely related to E. coli, although they had diverged sufficiently to warrant a novel species name. Unfortunately, new isolates continue to be mistyped as enteropathogenic E. coli (EPEC) or enterohemorrhagic E. coli (EHEC) owing to shared traits, most notably the ability to form A/E lesions. Consequently, E. albertii remains an underappreciated A/E pathogen, despite multiple reports demonstrating that many provisional EPEC and EHEC isolates incriminated in disease outbreaks are actually E. albertii Metagenomic studies on dozens of E. albertii isolates reveal a genetic architecture that boasts an arsenal of candidate virulence factors to rival that of its better-characterized cousins, EPEC and EHEC. Beyond these computational comparisons, studies addressing the regulation, structure, function, and mechanism of action of its repertoire of virulence factors are lacking. Thus, the paucity of knowledge about the epidemiology, virulence, and antibiotic resistance of E. albertii, coupled with its misclassification and its ability to develop multidrug resistance in a single step, highlights the challenges in combating this emerging pathogen. This review seeks to synthesize our current but incomplete understanding of the biology of E. albertii.

Nod2 Deficiency in mice is Associated with Microbiota Variation Favouring the Expansion of mucosal CD4+ LAP+ Regulatory Cells.

Nucleotide-binding Oligomerization Domain-2 (NOD2) mutations are associated with an increased risk to develop Crohn's Disease. In previous studies, we have shown that Nod2-/- mice manifest increased proportion of Lamina Propria (LP) CD4+ LAP+ Foxp3- regulatory cells, when compared with Nod2+/+ mice, while CD4+ Foxp3 + regulatory cells were not affected. Here, we investigated the Nod2 gut microbiota, by 16S rRNA pyrosequencing, at steady state and after TNBS-colitis induction in mice reared separately or in cohousing, correlating the microbial profiles with LP regulatory T cells proportion and tissue cytokines content. We found that enrichment of Rikenella and Alistipes (Rikenellaceae) in Nod2-/- mice at 8 weeks of age reared separately was associated with increased proportion of CD4+ LAP+ Foxp3- cells and less severe TNBS-colitis. In co-housed mice the acquisition of Rickenellaceae by Nod2+/+ mice was associated with increased CD4+ LAP+ Foxp3- proportion and less severe colitis. Severe colitis was associated with enrichment of gram-negative pathobionts (Escherichia and Enterococcus), while less severe colitis with protective bacteria (Barnesiella, Odoribacter and Clostridium IV). Environmental factors acting on genetic background with different outcomes according to their impact on microbiota, predispose in different ways to inflammation. These results open a new scenario for therapeutic attempt to re-establish eubiosis in Inflammatory Bowel Disease patients with NOD2 polymorphisms.

Proteomics Goes to Court: A Statistical Foundation for Forensic Toxin/Organism Identification Using Bottom-Up Proteomics.

Bottom-up proteomics is increasingly being used to characterize unknown environmental, clinical, and forensic samples. Proteomics-based bacterial identification typically proceeds by tabulating peptide "hits" (i.e., confidently identified peptides) associated with the organisms in a database; those organisms with enough hits are declared present in the sample. This approach has proven to be successful in laboratory studies; however, important research gaps remain. First, the common-practice reliance on unique peptides for identification is susceptible to a phenomenon known as signal erosion. Second, no general guidelines are available for determining how many hits are needed to make a confident identification. These gaps inhibit the transition of this approach to real-world forensic samples where conditions vary and large databases may be needed. In this work, we propose statistical criteria that overcome the problem of signal erosion and can be applied regardless of the sample quality or data analysis pipeline. These criteria are straightforward, producing a p-value on the result of an organism or toxin identification. We test the proposed criteria on 919 LC-MS/MS data sets originating from 2 toxins and 32 bacterial strains acquired using multiple data collection platforms. Results reveal a > 95% correct species-level identification rate, demonstrating the effectiveness and robustness of proteomics-based organism/toxin identification.

[Escherichia vulneris etiologic agent of septic arthritis in a child]. / Escherichia vulneris como agente etiológico de artritis séptica en una niña.

Escherichia vulneris is a gram-negative bacillus that belongs to the family Enterobacteriaceae, with a questioned pathogenic role. However, it has been confirmed as the cause of wound infections. We report the case of a 12-year-old girl, previously healthy, with a diagnosis of septic arthritis of the right knee, secondary to a spinal lesion. Escherichia vulneris, an unusual etiology of septic arthritis in children, was isolated in the joint fluid. This case is one of the first cases of septic arthritis due to E. vulneris, secondary to a plant-derived foreign body in a child, described in the medical literature. The importance of performing the microbiological study of joint fluid in patients with septic arthritis caused by a foreign body of plant-derived origin is emphasized.

Escherichia vulneris como agente etiológico de artritis séptica en una niña / Escherichia vulneris etiologic agent of septic arthritis in a child

Resumen Escherichia vulneris es un bacilo gramnegativo, perteneciente a la familia Enterobacteriaceae, cuyo rol patógeno ha sido cuestionado. Sin embargo, se ha confirmado principalmente como causante de infecciones de heridas. Presentamos el caso de una niña de 12 años, previamente sana, con diagnóstico de una artritis séptica de rodilla derecha secundaria a una lesión con espina vegetal. En el estudio del líquido articular se aisló E. vulneris, una etiología poco habitual de artritis séptica en niños. Es uno de los primeros casos de artritis séptica por E. vulneris, secundaria a un cuerpo extraño vegetal en un niño, descritos en la literatura médica. Se enfatiza la importancia de realizar el estudio microbiológico del líquido articular en pacientes con artritis séptica originada por un cuerpo extraño de origen vegetal.

Escherichia vulneris is a gram-negative bacillus that belongs to the family Enterobacteriaceae, with a questioned pathogenic role. However, it has been confirmed as the cause of wound infections. We report the case of a 12-year-old girl, previously healthy, with a diagnosis of septic arthritis of the right knee, secondary to a spinal lesion. Escherichia vulneris, an unusual etiology of septic arthritis in children, was isolated in the joint fluid. This case is one of the first cases of septic arthritis due to E. vulneris, secondary to a plant-derived foreign body in a child, described in the medical literature. The importance of performing the microbiological study of joint fluid in patients with septic arthritis caused by a foreign body of plant-derived origin is emphasized.

Clinical characteristics and outcomes of spontaneous bacterial peritonitis caused by Enterobacter species versus Escherichia coli: a matched case-control study.

BACKGROUND: Enterobacter species are important nosocomial pathogens, and there is growing concern about their ability to develop resistance during antimicrobial therapy. However, few data are available on the clinical characteristics and outcomes of Enterobacter spontaneous bacterial peritonitis (SBP). METHODS: We retrospectively identified all patients with SBP caused by Enterobacter species admitted to a tertiary care hospital between January 1997 and December 2013. Each case was age- and sex-matched with four patients with Escherichia coli SBP. RESULTS: A total of 32 cases with Enterobacter SBP and 128 controls with E. coli SBP were included. Twenty-one (65.6 %) cases and 111 (86.7 %) controls had Child-Pugh class C (P = 0.006). Cases were significantly more likely to have hepatocellular carcinoma (65.6 % vs. 37.5 %, P = 0.004) and upper gastrointestinal bleeding (28.1 % vs. 9.4 %, P = 0.005). The initial response to empirical therapy (81.3 % vs. 81.2 %, P = 0.995) and the 30-day mortality (37.5 % vs. 28.9 %, P = 0.35) were not significantly different between the groups. Drug resistance emerged in one case and in no controls (4.3 % [1/23] vs. 0 % [0/98], P = 0.19). CONCLUSIONS: Compared with E. coli SBP, patients with Enterobacter SBP more frequently had hepatocellular carcinoma and upper gastrointestinal bleeding, yet clinical outcomes were comparable. Development of resistance during third-generation cephalosporin therapy was infrequent in patients with Enterobacter SBP.

Perilla Oil Has Similar Protective Effects of Fish Oil on High-Fat Diet-Induced Nonalcoholic Fatty Liver Disease and Gut Dysbiosis.

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease in developed countries. Recent studies indicated that the modification of gut microbiota plays an important role in the progression from simple steatosis to steatohepatitis. Epidemiological studies have demonstrated consumption of fish oil or perilla oil rich in n-3 polyunsaturated fatty acids (PUFAs) protects against NAFLD. However, the underlying mechanisms remain unclear. In the present study, we adopted 16s rRNA amplicon sequencing technique to investigate the impacts of fish oil and perilla oil on gut microbiomes modification in rats with high-fat diet- (HFD-) induced NAFLD. Both fish oil and perilla oil ameliorated HFD-induced hepatic steatosis and inflammation. In comparison with the low-fat control diet, HFD feeding significantly reduced the relative abundance of Gram-positive bacteria in the gut, which was slightly reversed by either fish oil or perilla oil. Additionally, fish oil and perilla oil consumption abrogated the elevated abundance of Prevotella and Escherichia in the gut from HFD fed animals. Interestingly, the relative abundance of antiobese Akkermansia was remarkably increased only in animals fed fish oil compared with HFD group. In conclusion, compared with fish oil, perilla oil has similar but slightly weaker potency against HFD-induced NAFLD and gut dysbiosis.

[Applicability of MALDI Mass Spectrometry for Diagnostics of Phase Variants in Bacterial Populations].

Efficiency of MALDI mass spectrometry for differentiation between phenotypic phase variants (in colony morphology and virulence/avirulence) was investigated.for saprotrophic and opportunistically pathogenic bacteria of five genera (Acinetobacter, Arthrobacter, Rhodococcus, Corynebacterium, and Escherichia). Analysis of MALDI spectra (on the SA and HCCA matrices) included: (1) determination of similarity of the protein spectra as a percentage of the common protein peaks to the total amount of proteins, which reflects the phylogenetic relationships of the objects and has been recommended for identification of closely related species; (2) comparison of intensities of the common peaks; and (3) the presence of specific peaks as determinative characteristics of the variants. Under the standard analytical conditions the similarity between the MALDI profiles was shown to increase in the row: genus-species-strain-variant. Assessment of intensities of the common peaks was most applicable for differentiation between phase variants, especially in the case of high similarity of their profiles. Phase variants (A. oxydans strain K14) with similar colony morphotypes (S, R, M, and S(m)) grown on different media (LB agar, TSA, and TGYg) exhibited differences in their protein profiles reflecting the differences in their physiological characteristics. This finding is in agreement with our previous results on screening of the R. opacus with similar colony morphology and different substrate specificity in decomposition of chlorinated phenols. Analysis of MALDI spectra is probably the only efficient method for detection of such variants.

The WNT signaling pathway contributes to dectin-1-dependent inhibition of Toll-like receptor-induced inflammatory signature.

Macrophages regulate cell fate decisions during microbial challenges by carefully titrating signaling events activated by innate receptors such as dectin-1 or Toll-like receptors (TLRs). Here, we demonstrate that dectin-1 activation robustly dampens TLR-induced proinflammatory signature in macrophages. Dectin-1 induced the stabilization of ß-catenin via spleen tyrosine kinase (Syk)-reactive oxygen species (ROS) signals, contributing to the expression of WNT5A. Subsequently, WNT5A-responsive protein inhibitors of activated STAT (PIAS-1) and suppressor of cytokine signaling 1 (SOCS-1) mediate the downregulation of IRAK-1, IRAK-4, and MyD88, resulting in decreased expression of interleukin 12 (IL-12), IL-1ß, and tumor necrosis factor alpha (TNF-α). In vivo activation of dectin-1 with pathogenic fungi or ligand resulted in an increased bacterial burden of Mycobacteria, Klebsiella, Staphylococcus, or Escherichia, with a concomitant decrease in TLR-triggered proinflammatory cytokines. All together, our study establishes a new role for dectin-1-responsive inhibitory mechanisms employed by virulent fungi to limit the proinflammatory environment of the host.

Characterization of Escherichia fergusonii and Escherichia albertii isolated from water.

AIMS: The aim of this study was to characterize Escherichia fergusonii and Escherichia albertii isolated from water. METHODS AND RESULTS: The characterization of E. fergusonii and E. albertii isolated from water was determined using an Escherichia coli-specific uidA PCR, a tuf PCR, and with phylogenetic analysis using three housekeeping genes (adk, gyrB, and recA) from the E. coli MLST scheme, selected for their ability to discriminate among all Escherichia species. Among the 527 isolates tested, 25 (4·7%) were uidA PCR negative and tuf PCR positive. Phylogenetic analysis using adk, gyrB and recA genes showed that 6, 18 and 1 of these 25 non-E. coli Escherichia spp. isolates grouped with reference strains of E. fergusonii, E. albertii, and E. coli, respectively. Finally, the 25 non-E. coli Escherichia spp. strains isolated were investigated for the presence of pathogenic factors, comprising intimin (eae gene), cytolethal distending toxin (cdtB gene) and shiga toxin (stx gene). With the PCR primers used, the presence of eae and stx genes was not detected. However, cdtB genes types I/IV were detected for 3 (16·7%) E. albertii strains, whereas 15 of 18 (83·3%) possessed the cdtB gene types II/III/V. CONCLUSIONS: These results showed that MLST scheme allows a more accurate identification of non-E. coli species than phenotypic tests. We also showed that E. fergusonii and E. albertii represent, respectively, 0·8 and 2·5% of all Escherichia species isolated and the pathogenic cdtB genes were present in 83·3% of these strains. SIGNIFICANCE AND IMPACT OF THE STUDY: The data presented in this study provided an efficient way to correctly identify non-E. coli species contributing to our understanding of the risks associated with Escherichia species in water consumed by humans and animals. Furthermore, the results give an insight about the natural habitats of these species.