Emergence of extended-spectrum β-lactamase (ESBL) and fluoroquinolone resistance among ocular Enterobacteriaceae is increasing in higher frequency. Therefore, studies are being carried out to understand their multidrug resistance pattern. A total of 101 Enterobacteriaceae isolates recovered from various ocular diseases in a tertiary eye care center at Chennai, India during the period of January 2011 to June 2014 were studied. Forty one randomly chosen isolates were subjected to antibiotic susceptibility by minimum inhibitory concentration (MIC) and genotypic analysis. Of them, 16 were ESBL producers, one was carbapenemase producer and four were resistant to ertapenem which could be due to porin loss associated with AmpC production, and 17 were resistant to fluoroquinolones. Sixteen isolates harbored ESBL genes in which 14 had more than one gene and none of them were positive for blaNDM-1 gene. QNR genes were detected in 18 isolates.
ESBL producers were predominantly isolated from conjunctiva. A high degree of ESBL production and fluoroquinolone resistance is seen among the genus Klebsiella sp. Hence, monitoring the rate of ESBL prevalence plays a vital role in the administration of appropriate intravitreal antibiotics to save the vision and also to reduce the development of drug resistance in ocular pathogens.
Authors:Maria Franziska Ostermann, Heinrich Neubauer, Hagen Frickmann, and Ralf Matthias Hagen
This study assessed the variation of phenotypic features of clinical isolates of Burkholderia spp. from common rpsU gene sequence clusters.
A total of 41 clinical Burkholderia spp. isolates from German mucoviscidosis patients was subjected to rpsU gene sequencing. Biochemical assessment included the API systems 20 NE and 50 CHE as well as the Micronaut NF system. Fatty acid patterns were assessed using gas chromatography—mass spectrometry (GC—MS). Broth microdilution was used to identify minimum inhibitory concentrations.
Five rpsU gene sequence clusters comprised more than one clinical isolate. Altogether, assignments to three species and seven clusters comprising more than one Burkholderia species were performed. Inhomogeneity of biochemical reactions within the clusters ranged from 0/28 to 45/50 reactions. The standard deviation for fatty acid distributions ranged from 0% to 11.5%. Minimum inhibitory concentrations within the clusters showed a wide variation but only minor differences between the clusters.
Broad variations within identified rpsU gene sequence clusters regarding biochemical reactions, fatty acid patterns, and resistance patterns of clinical Burkholderia spp. isolates make the application of rpsU gene sequence analysis as a stand-alone procedure for discriminations within the Burkholderia cepacia complex unreliable.
Authors:E. Sapi, K. Balasubramanian, A. Poruri, J. S. Maghsoudlou, K. M. Socarras, A. V. Timmaraju, K. R. Filush, K. Gupta, S. Shaikh, P. A. S. Theophilus, D. F. Luecke, A. MacDonald, and B. Zelger
Lyme borreliosis, caused by the spirochete Borrelia burgdorferi sensu lato, has grown into a major public health problem. We recently identified a novel morphological form of B. burgdorferi, called biofilm, a structure that is well known to be highly resistant to antibiotics. However, there is no evidence of the existence of Borrelia biofilm in vivo; therefore, the main goal of this study was to determine the presence of Borrelia biofilm in infected human skin tissues. Archived skin biopsy tissues from borrelial lymphocytomas (BL) were reexamined for the presence of B. burgdorferi sensu lato using Borrelia-specific immunohistochemical staining (IHC), fluorescent in situ hybridization, combined fluorescent in situ hybridization (FISH)–IHC, polymerase chain reaction (PCR), and fluorescent and atomic force microscopy methods. Our morphological and histological analyses showed that significant amounts of Borrelia-positive spirochetes and aggregates exist in the BL tissues. Analyzing structures positive for Borrelia showed that aggregates, but not spirochetes, expressed biofilm markers such as protective layers of different mucopolysaccharides, especially alginate. Atomic force microscopy revealed additional hallmark biofilm features of the Borrelia/alginate-positive aggregates such as inside channels and surface protrusions. In summary, this is the first study that demonstrates the presence of Borrelia biofilm in human infected skin tissues.
Authors:Cosme Alvarado-Esquivel, Luis Francisco Sánchez-Anguiano, Jesús Hernández-Tinoco, Edwin Adiel Calzada-Torres, Sergio Estrada-Martínez, Alma Rosa Pérez-Álamos, Raquel Vaquera-Enriquez, Arturo Díaz-Herrera, Raúl Segura-Moreno, María de Lourdes Guerrero-Carbajal, María Guadalupe Rentería-López, Isabel Beristain García, Elizabeth Rábago-Sánchez, and Oliver Liesenfeld
Some symptoms of menopause have also been described in patients with toxoplasmosis. Whether Toxoplasma gondii (T. gondii) infection has any influence on clinical manifestations of menopause is yet unknown. We sought to determine whether T. gondii exposure is associated with symptoms and signs of menopause. We performed a cross-sectional study of women attending a public health center in Durango City, Mexico. Participants were examined for the presence of anti-Toxoplasma IgG and IgM antibodies using enzyme-linked immunoassays. A questionnaire including 47 symptoms and signs potentially associated with menopause was applied. Association of seroprevalence for T. gondii with clinical characteristics of women was assessed by bivariate and multivariate analyses. Bivariate analysis showed that bouts of rapid heartbeat, breast pain, electric shock sensation, dizziness, digestive problems, low back pain, and migraine were associated with seropositivity to either IgG anti-T. gondii alone or both IgG and IgM anti-T. gondii. Breast pain was the only variable that was found to be associated with IgG seropositivity to T. gondii by multivariate analysis: (OR = 2.84; 95% CI: 1.35–5.90; P = 0.005). Our results suggest that T. gondii exposure may influence on the clinical manifestations of menopause. Results deserve further research.
Authors:Markus M. Heimesaat, Thomas Alter, Stefan Bereswill, and Greta Gölz
We have previously shown that Arcobacter butzleri induces intestinal, extra-intestinal, and systemic immune responses in perorally infected gnotobiotic IL-10−/− mice in a strain-dependent fashion. Here, we present a comprehensive survey of small and large intestinal expression profiles of inflammatory and regulatory mediators as well as of the matrix-degrading gelatinases MMP-2 and MMP-9 following murine A. butzleri infection. Gnotobiotic IL-10−/− mice were infected with A. butzleri strains CCUG 30485 or C1 of human and chicken origin, respectively. At day 6 following A. butzleri infection, mucin-2 mRNA, an integral part of the intestinal mucus layer, was downregulated in the colon, whereas TNF and IL-23p19 mRNA were upregulated in the ileum. Furthermore, IFN-γ, IL-17A, IL-1β, and IL-22 mRNA were upregulated in both colonic and ileal ex vivo biopsies at day 6 post strain CCUG 30485 infection. These changes were accompanied by downregulated colonic MMP-9 levels, whereas both MMP-2 and MMP-9 mRNA were upregulated in the ileum. In conclusion, these data indicate that A. butzleri infection induces changes in the expression of genes involved in pro-inflammatory and regulatory immune responses as well as in tissue degradation.
Authors:Anne Katrine Blaabjerg, Anna Holst Schumacher, Bjørn Kantsø, Lena Hagelskjær Kristensen, and Helga Schumacher
This is the first case report of recurrent invasive pneumococcal disease (IPD), specifically, due to serotype 12F. The patient described here was vaccinated with the 23-valent pneumococcal polysaccharide vaccine (PPV23) due to previous splenectomy, and an anti-pneumococcal IgG test concluded that she had responded sufficiently to vaccination. Still, she had a fulminate recurrent infection with PPV23 serotype 12F. We investigated the anti-pneumococcal IgG test, and it turned out that it is based on the geometric mean value of only 12 of the serotypes included in PPV23; 12F is none of them. The reason is that there are no titer cut-offs available for 11 of the PPV23 serotypes, including 12F, neither nationally nor internationally. Yet, this is not specified in the answer to the clinicians. This case illustrates the need for titer cut-offs for the remaining pneumococcal serotypes in available vaccines, in order to get a more accurate estimation of the vaccination coverage for the individual patient. Therefore, more research on this area is warranted, along with a discussion of whether the laboratory answers to the clinicians should be more detailed.
Authors:Munisch Wadwa, Robert Klopfleisch, Jan Buer, and Astrid M. Westendorf
The endocytotic c-type lectin receptor DEC-205 is highly expressed on immature dendritic cells. In previous studies, it was shown that antigen-targeting to DEC-205 is a useful tool for the induction of antigen-specific Foxp3+ regulatory T cells and thereby can prevent inflammatory processes. However, whether this approach is sufficient to mediate tolerance in mucosal tissues like the gut is unknown. In this study, we established a new mouse model in which the adoptive transfer of naive hemagglutinin (HA)-specific CD4+Foxp3− T cells into VILLIN-HA transgenic mice leads to severe colitis. To analyze if antigen-targeting to DEC-205 could protect against inflammation of the gut, VILLIN-HA transgenic mice were injected with an antibody–antigen complex consisting of the immunogenic HA110–120 peptide coupled to an α-DEC-205 antibody (DEC-HA) before adoptive T cell transfer. DEC-HAtreated mice showed significantly less signs of intestinal inflammation as was demonstrated by reduced loss of body weight and histopathology in the gut. Strikingly, abrogated intestinal inflammation was mediated via the conversion of naive HA-specific CD4+Foxp3− T cells into HA-specific CD4+Foxp3+ regulatory T cells. In this study, we provide evidence that antigen-targeting to DEC-205 can be utilized for the induction of tolerance in mucosal organs that are confronted with large numbers of exogenous antigens.
Authors:Greta Gölz, Thomas Alter, Stefan Bereswill, and Markus M. Heimesaat
We have previously shown that Arcobacter butzleri infection induces Toll-like receptor (TLR) -4 dependent immune responses in perorally infected gnotobiotic IL-10−/− mice. Here, we analyzed TLR-4-dependent expression of genes encoding inflammatory mediators and matrix-degrading gelatinases MMP-2 and -9 in the small and large intestines of gnotobiotic TLR-4-deficient IL-10−/− mice that were perorally infected with A. butzleri strains CCUG 30485 or C1, of human and chicken origin, respectively. At day 6 following A. butzleri infection, colonic mucin-2 mRNA, as integral part of the intestinal mucus layer, was downregulated in the colon, but not ileum, of IL-10−/− but not TLR-4−/− IL-10−/− mice. CCUG 30485 strain-infected TLR-4-deficient IL-10−/− mice displayed less distinctly upregulated IFN-γ, IL-17A, and IL-1β mRNA levels in ileum and colon, which was also true for colonic IL-22. These changes were accompanied by upregulated colonic MMP-2 and ileal MMP-9 mRNA exclusively in IL-10−/− mice. In conclusion, TLR-4 is essentially involved in A. butzleri mediated modulation of gene expression in the intestines of gnotobiotic IL-10−/− mice.
Authors:P. Milanez-Almeida, T. Ulas, M. Pasztoi, S. Glage, K. Schughart, M. B. Lutz, J. L. Schultze, and J. Huehn
Influenza A virus (IAV) infection causes an acute respiratory disease characterized by a strong inflammatory immune response and severe immunopathology. Proinflammatory mechanisms are well described in the murine IAV infection model, but less is known about the mechanisms leading to the resolution of inflammation. Here, we analyzed the contribution of CD11b+Ly6C++Ly6G− cells to this process. An accumulation of CD11b+Ly6C++Ly6G− cells within the lungs was observed during the course of IAV infection. Phenotypic characterization of these CD11b+Ly6C++Ly6G− cells by flow cytometry and RNA-Seq revealed an activated phenotype showing both pro- and anti-inflammatory features, including the expression of inducible nitric oxide synthase (iNOS) by a fraction of cells in an IFN-γ-dependent manner. Moreover, CD11b+Ly6C++Ly6G− cells isolated from lungs of IAV-infected animals displayed suppressive activity when tested in vitro, and iNOS inhibitors could abrogate this suppressive activity. Collectively, our data suggest that during IAV infection, CD11b+Ly6C++Ly6G− cells acquire immunoregulatory function, which might contribute to the prevention of pathology during this life-threatening disease.