Authors:I. Løbersli, A. L. Wester, Å. Kristiansen, and L. T. Brandal
A real-time polymerase chain reaction (PCR) assay, amplifying the genes encoding lactose permease (lacY) and invasion plasmid antigen H (ipaH), was run on 121 isolates phenotypically classified as Shigella spp., enteroinvasive Escherichia coli (EIEC), or EIEC O nontypable (ONT). The results were compared with data from a generic E. coli multiple-locus variable-number of tandem repeat analysis (MLVA) and a Shigella MLVA.
The real-time PCR verified all Shigella spp. (n = 53) as Shigella (lacY negative) and all EIEC O121 (n = 15) and EIEC O124 (n = 2) as EIEC (lacY positive). However, the real-time PCR typed EIEC O164 as either EIEC (n = 2) or Shigella (n = 2) and, thus, was not suited for classifying this group of isolates. Interestingly, the majority (42/47, 89.4%) of the EIEC ONT were classified as Shigella (lacY negative) by the real-time PCR, and in nearly all cases, (92.9%, 39/42) data from both MLVA assays supported these findings. Overall, in 94.7% (114/121) of the isolates, the results from the real-time PCR were substantiated by the results from the MLVA assays.
In conclusion, the real-time PCR assay was fast and accurate in differentiating Shigella spp. from EIEC, with the exception of the EIEC O164 group. This molecular assay was particularly pragmatic for the challenging EIEC ONT group.
Authors:G. Odewale, O. J. Adefioye, J. Ojo, F. A. Adewumi, and O. A. Olowe
Acinetobacter baumannii is a ubiquitous pathogen that has emerged as a major cause of healthcare-associated infections at Ladoke Akintola University Teaching Hospital. Isolates were assayed according to standard protocol. The isolates were subjected to molecular techniques to detect blaOXA, blaTEM, blaCTX-M, and blaSHV genes in strains of the A. baumannii isolates.
The prevalence of A. baumannii was 8.5% and was most prevalent among patients in the age group 51–60 (36%); the male patients (63.6%) were more infected than their female counterparts. Patients (72.7%) in the intensive care unit (ICU) were most infected with this organism. The isolates showed 100% resistance to both amikacin and ciprofloxacin and 90.9% to both ceftriaxone and ceftazidime, while resistance to the other antibiotics used in this study were: piperacillin (81.8%), imipenem (72.7%), gentamycin (72.2%), and meropenem (63.6%). None of the isolates was, however, resistant to colistin. PCR results showed that blaOXA, blaTEM, and blaCTX-M genes were positive in some isolates, while blaSHV was not detected in any of the isolates.
This study has revealed that the strains of A. baumannii isolated are multiple drug resistant. Regular monitoring, judicious prescription, and early detection of resistance to these antibiotics are, therefore, necessary to check further dissemination of the organism.
Authors:Hagen Frickmann, Wibke Schmeja, Emil Reisinger, Thomas Mittlmeier, Karen Mitzner, Norbert Georg Schwarz, Philipp Warnke, and Andreas Podbielski
This study assessed protective effects of a continuous introduction of safe instruments in terms of reduction of needle stick injuries. The retrospective study analyzed correlations between the increasing proportion of safe instruments and a reduction of the incidence of needle stick injuries linked to such instruments in a German university hospital over 5 years. Incidents declined about 17.6% from 80.3 incidents per 1000 employees to 66.2, associated with an increase in the proportions of injuries due to instruments without protective mechanisms such as scalpels or hypodermic needles by 12.2%. For injuries due to venipuncture cannulae in various surgical and internal medicine departments, there was a negative association between the proportion of safe instruments and the incidence of injuries. For injection needles, portacath needles, and lancets in selected internal medicine departments, the number of injuries also dropped during this study interval. However, there was no clear-cut association with the percentage of safe instruments. This observational study suggests a correlation between the implementation of use of safe instruments and the reduction of needle stick injuries in a case of a graduated implementation. However, the effects are much less pronounced than in previous interventional studies.
Authors:Walaa S. Khater, Noha N. Salah-Eldeen, Mohamed S. Khater, and Ashraf N. Saleh
This study investigated the diagnostic value of soluble urokinase plasminogen activator receptor (suPAR) and serum lactate in elderly patients with sepsis and evaluated their capacity to predict mortality and their correlation to Sequential Organ Failure Assessment (SOFA) score. The study included 80 participants, divided into two groups: 40 cases (mean age, 68.9 ± 5.9) admitted to the intensive care unit and 40 healthy controls (mean age, 67.1 ± 6.2). Elderly patients with sepsis had significantly higher levels of serum suPAR and lactic acid compared to healthy controls. Receiver operating characteristic (ROC) curve analysis showed that suPAR (cutoff value, ≥4.37 ng/ml) has higher area under the curve (AUC) than lactic acid (cutoff value, ≥1.95 mmol/l) for diagnosing sepsis. Serum lactate has superior prognostic value compared to suPAR with AUC of 0.82 (cutoff value, 2.2 mmol/l) and 0.72 (cutoff value, 6.3 ng/ml), respectively. The diagnostic power of combined usage of suPAR and lactate serum concentrations showed AUC of 0.988 (95% confidence interval 0.934 to 1.0). The combination of both biomarkers either together or with SOFA score may serve as a useful guide to patients who need more intensive resuscitation.
Upon differentiation, T cells acquire tissue-specific homing properties allowing efficient targeting of effector T cells into distinct inflamed organs. Priming of T cells within skin-draining, peripheral lymph nodes (pLNs) leads to the expression of E- and P-selectin ligands, which facilitate migration into inflamed skin, whereas activation within gut-draining, mesenteric LNs (mLNs) results in induction of chemokine receptor CCR9 and integrin α4β7, both required for migration of effector T cells into mucosal tissues. In addition to the local tissue microenvironment, both organ-specific dendritic cells and LN-resident stromal cells are critical factors to shape T cell migration properties. Here, we identify two additional homing-related molecules, CCR6 and Neuropilin-1 (Nrp1), upregulated in T cells early during differentiation solely in pLNs, but not mLNs. Surprisingly, intestinal inflammation resulted in an ameliorated induction of CCR6 and Nrp1 in pLNs, suggesting that a local inflammation within the gut can systemically alter T cell differentiation. Finally, transplantation of mLNs to a skin-draining environment revealed that LN stromal cells also contribute to efficient CCR6 induction in pLNs. Collectively, these findings identify further aspects of early T cell differentiation within skin-draining pLNs, which could be utilized to further develop tailored and highly specialized vaccination strategies.
Authors:Markus M. Heimesaat, Ursula Grundmann, Marie E. Alutis, André Fischer, Ulf B. Göbel, and Stefan Bereswill
Within 1 week following peroral Campylobacter jejuni infection, infant mice develop acute enteritis resolving thereafter. We here assessed colonic expression profiles of mediators belonging to the IL-23/IL-22/IL-18 axis and of matrix-degrading gelatinases MMP-2 and MMP-9 at day 6 post C. jejuni strain 81-176 infection. Whereas the pathogen readily colonized the intestines of infant IL-18−/− mice only, colonic mucin-2 mRNA, a pivotal mucus constituent, was downregulated in IL-22−/− mice and accompanied by increased expression of pro-inflammatory cytokines including IFN-γ, TNF, IL-17A, and IL-1β. Furthermore, in both naive and infected IL-22−/− mice, colonic expression of IL-23p19 and IL-18 was lower as compared to wildtype mice, whereas, conversely, colonic IL-22 mRNA levels were lower in IL-18−/− and colonic IL-18 expression lower in IL-23p19−/− as compared to wildtype mice. Moreover, colonic expression of MMP-2 and MMP-9 and their endogenous inhibitor TIMP-1 were lower in IL-22−/− as compared to wildtype mice at day 6 postinfection. In conclusion, mediators belonging of the IL-23/IL-22/IL-18 axis as well as the gelatinases MMP-2 and MMP-9 are involved in mediating campylobacteriosis of infant mice in a differentially regulated fashion.
Authors:Jennifer zur Bruegge, Christina Backes, Greta Gölz, Georg Hemmrich-Stanisak, Lydia Scharek-Tedin, Andre Franke, Thomas Alter, Ralf Einspanier, Andreas Keller, and Soroush Sharbati
The role of microRNAs (miRNAs) in infectious diseases is becoming more and more apparent, and the use of miRNAs as a diagnostic tool and their therapeutic application has become the major focus of investigation. The aim of this study was to identify miRNAs involved in the immune signaling of macrophages in response to Arcobacter (A.) butzleri infection, an emerging foodborne pathogen causing gastroenteritis. Therefore, primary human macrophages were isolated and infected, and miRNA expression was studied by means of RNAseq. Analysis of the data revealed the expression of several miRNAs, which were previously associated with bacterial infections such as miR-155, miR-125, and miR-212. They were shown to play a key role in Toll-like receptor signaling where they act as fine-tuners to establish a balanced immune response. In addition, miRNAs which have yet not been identified during bacterial infections such as miR-3613, miR-2116, miR-671, miR-30d, and miR-629 were differentially regulated in A. butzleri-infected cells. Targets of these miRNAs accumulated in pathways such as apoptosis and endocytosis — processes that might be involved in A. butzleri pathogenesis. Our study contributes new findings about the interaction of A. butzleri with human innate immune cells helping to understand underlying regulatory mechanisms in macrophages during infection.
Authors:Heike Granzer, Ralf Matthias Hagen, Philipp Warnke, Wolfgang Bock, Tobias Baumann, Norbert Georg Schwarz, Andreas Podbielski, Hagen Frickmann, and Thomas Koeller
This study addressed carbapenem-resistant Acinetobacter baumannii complex (ABC) isolates from patients that were injured during the military conflict in the Eastern Ukraine and treated at German Armed Forces Hospitals in 2014 and 2015. Clonal diversity of the strains and potential ways of transmission were analyzed.
Patients with one or several isolation events of carbapenem-resistant ABC were included. Isolates were characterized by VITEK II-based identification and resistance testing, molecular screening for frequent carbapenemase genes, and DiversiLab rep-PCRbased typing. Available clinical information of the patients was assessed.
From 21 young male Ukrainian patients with battle injuries, 32 carbapenem- and fluoroquinolone-resistant ABC strains were isolated. Four major clonal clusters were detected. From four patients (19%), ABC isolates from more than one clonal cluster were isolated. The composition of the clusters suggested transmission events prior to the admission to the German hospitals.
The infection and colonization pressure in the conflict regions of the Eastern Ukraine with ABC of low clonal diversity is considerable. Respective infection risks have to be considered in case of battle-related injuries in these regions. The low number of local clones makes any molecular exclusion of transmission events difficult.
Authors:Markus M. Heimesaat, Marie E. Alutis, Ursula Grundmann, André Fischer, Ulf B. Göbel, and Stefan Bereswill
We have recently shown that, within 1 week following peroral Campylobacter jejuni infection, conventional infant mice develop self-limiting enteritis. We here investigated the role of IL-23, IL-22, and IL-18 during C. jejuni strain 81-176 infection of infant mice. The pathogen efficiently colonized the intestines of IL-18−/− mice only, but did not translocate to extra-intestinal compartments. At day 13 postinfection (p.i.), IL-22−/− mice displayed lower colonic epithelial apoptotic cell numbers as compared to wildtype mice, whereas, conversely, colonic proliferating cells increased in infected IL-22−/− and IL-18−/− mice. At day 6 p.i., increases in neutrophils, T and B lymphocytes were less pronounced in gene-deficient mice, whereas regulatory T cell numbers were lower in IL-23p19−/− and IL-22−/− as compared to wildtype mice, which was accompanied by increased colonic IL-10 levels in the latter. Until then, colonic pro-inflammatory cytokines including TNF, IFN-γ, IL-6, and MCP-1 increased in IL-23p19−/− mice, whereas IL-18−/− mice exhibited decreased cytokine levels and lower colonic numbers of T and B cell as well as of neutrophils, macrophages, and monocytes as compared to wildtype controls. In conclusion, IL-23, IL-22, and IL-18 are differentially involved in mediating C. jejuni-induced immunopathology of conventional infant mice.
Authors:Cosme Alvarado-Esquivel, Luis Francisco Sánchez-Anguiano, Jesús Hernández-Tinoco, Rosa Angélica Pulido-Montoya, Guadalupe Acosta-Rojas, Sergio Estrada-Martínez, Alma Rosa Pérez-Álamos, Raquel Vaquera-Enriquez, Arturo Díaz-Herrera, Raúl Segura-Moreno, María de Lourdes Guerrero-Carbajal, Oliver Liesenfeld, Isabel Beristain García, and María Guadalupe Rentería-López
Medical certificates are documents that state the health status of a person. This study aimed to determine the seroprevalence and risk factors for Toxoplasma gondii infection in applicants of medical certificates and to investigate seroprevalence association with characteristics of these individuals. We examined 404 applicants in a public health center in Durango City, Mexico for the presence of anti-Toxoplasma IgG and IgM antibodies using enzyme-linked immunoassays. Of the 404 subjects (mean age of 35.94 ± 13.01) studied, 29 (7.2%) were positive for anti-T. gondii IgG antibodies and 9 (31.0%) of them were also positive for anti-T. gondii IgM antibodies. IgG and IgM seropositivities were associated with vision impairment (P = 0.04) and a history of surgery (P = 0.03), respectively. Prevalence of high (>150 IU/ml) IgG antibody levels was associated with hearing impairment (P = 0.03), and histories of lymphadenopathy (P = 0.04) and miscarriages (P = 0.03). Multivariate analysis showed that T. gondii seropositivity was associated with being born out of Durango State (odds ratio [OR] = 4.65; 95% confidence interval [CI]: 1.25– 17.29; P = 0.02) and soil contact (OR = 4.27; 95% CI: 1.71–10.67; P = 0.002) and negatively associated with consumption of sheep meat (OR = 0.12; 95% CI: 0.02–0.65; P = 0.01). These results could be used for the design of optimal preventive measures against toxoplasmosis and its sequelae.