Reduced Fluoroquinolone Susceptibility in Salmonella enterica Isolates from Travelers, Finland

We tested the fluoroquinolone susceptibility of 499 Salmonella enterica isolates collected from travelers returning to Finland during 2003–2007. Among isolates from travelers to Thailand and Malaysia, reduced fluoroquinolone susceptibility decreased from 65% to 22% (p = 0.002). All isolates showing nonclassical quinolone resistance were from travelers to these 2 countries.     

Salmonella enterica Serovar Agbeni, British Columbia, Canada, 2011

TO THE EDITOR: Infection with Salmonella enterica serovar Agbeni is rare. In Canada, it was reported 8 times during 2000-2010 and never in the province of British Columbia (2011 population?4.5 million) (Public Health Agency of Canada, unpub. data). In June 2011, an outbreak of S. enterica ser. Agbeni affecting 8 persons was identified in British Columbia; pulsed-field gel electrophoresis patterns for all isolates were identical. Although no specific source was identified, 2 features were noted: 1) diagnosis through urine specimens for 3 of 8 persons and 2) a longer than typical incubation period for Salmonella spp. infection.     

广东省2007-2016年人源沙门菌流行现状及病原学特征

目的 了解广东省人源沙门菌1,4,[5],12：i：-的流行现状、耐药性与分子特征。方法 对2007－2016年广东省沙门菌腹泻病例监测检出的人源沙门菌1,4,[5],12：i：-进行药物敏感试验、PCR检测和PFGE分型。结果 2007－2016年广东省共检出人源沙门菌1,4,[5],12：i：-2 960株,检出率逐年增多,至2015年成为广东省人源沙门菌中最主要的血清型。病例中男女性别比为1.58∶1,发病年龄以婴幼儿为主。沙门菌1,4,[5],12：i：-除对亚胺培南100%敏感外,对其他17种抗生素均有不同程度的耐药。2011－2016年对头孢他啶、头孢噻肟和环丙沙星的耐药率呈上升趋势。多重耐药现象严重,具有ASSuT多重耐药的有70.62%（435/616）,具有ACSuGSTTm多重耐药的有27.11%（167/616）。第Ⅱ相鞭毛蛋白不表达主要（75.53%）是缺失fljA、fljB和hin基因,但保留了iroB、STM2740、STM2757基因,共有8种不同的缺失方式。2 347株菌有934种PFGE谱型别,表现出较大的指纹图谱多态性,最主要的优势PFGE谱型为JPXX01.GD0226型（97株菌,4.13%）。168株沙门菌1,4,[5],12：i：-的PFGE图谱与鼠伤寒沙门菌PFGE图谱一致。结论 沙门菌1,4,[5],12：i：-已成为广东省人源沙门菌中最主要的血清型,且多重耐药现象严重,第Ⅱ相鞭毛蛋白不表达主要由缺失fljA、fljB和hin基因引起,其PFGE型别多样,呈遗传多态性。     

Extended-Spectrum Cephalosporin-Resistant Salmonella enterica serovar Heidelberg Strains,the Netherlands

Extended-spectrum cephalosporin-resistant Salmonella enterica serovar Heidelberg strains (JF6X01.0022/XbaI.0251, JF6X01.0326/XbaI.1966, JF6X01.0258/XbaI.1968, and JF6X01.0045/XbaI.1970) have been identified in the United States with pulsed-field gel electrophoresis. Our examination of isolates showed introduction of these strains in the Netherlands and highlight the need for active surveillance and intervention strategies by public health organizations.     

Transmission of Multidrug-Resistant Salmonella enterica Subspecies enterica 4,[5],12:i:- Sequence Type 34 between Europe and the United States

Multidrug-resistant Salmonella enterica subspecies enterica 4,[5],12:i:- sequence type 34 represents a worldwide public health risk. To determine its origin in the United States, we reconstructed a time-scaled phylogeny with a discrete trait geospatial model. The clone in the United States was introduced from Europe on multiple occasions in the early 2000s.     

Potential international spread of multidrug-resistant invasive Salmonella enterica serovar enteritidis

In developing countries, Salmonella enterica serovar Enteritidis causes substantial illness and death, and drug resistance is increasing. Isolates from the United Kingdom containing virulence-resistance plasmids were characterized. They mainly caused invasive infections in adults linked to Africa. The common features in isolates from these continents indicate the role of human travel in their spread.     

A Comparison of Subtyping Methods for Differentiating Salmonella enterica Serovar Enteritidis Isolates Obtained from Food and Human Sources

PurposeTo evaluate the abilities of these subtyping methods, we distinguished Salmonella Enteritidis (S. Enteritidis) isolated from food products and human clinical samples between 2009 and 2010 in Seoul using five subtyping methods.MethodsWe determined the subtypes of 20 S. Enteritidis isolates from food and human sources using phage typing, antimicrobial susceptibility, pulsed-field gel electrophoresis (PFGE), repetitive sequence-based PCR (rep-PCR), and multilocus sequence typing (MLST).ResultsA total of 20 tested isolates were differentiated into six antimicrobial susceptibility patterns, three different phage types, four different PFGE profiles, seven rep-PCR patterns, and one MLST type. Food isolates were considerably more susceptible to antibiotics than human isolates. We were best able to discriminate among S. Enteritidis isolates using rep-PCR, and obtained the highest Simpson's diversity index of 0.82, whereas other methods produced indices that were less than 0.71. PFGE pattern appeared to be more related to antimicrobial resistance and phage types of S. Enteritidis isolates than rep-PCR. MLST revealed identical alleles in all isolates at all seven loci examined, indicating no resolution.ConclusionThe results of this study suggest that rep-PCR provided the best discriminatory power for phenotypically similar S. Enteritidis isolates of food and human origins, whereas the discriminatory ability of MLST may be problematic because of the high sequence conservation of the targeted genes.     

Salmonella enterica Serotype Enteritidis in French Polynesia,South Pacific, 2008–2013

Outbreaks of Salmonella enterica serotype Enteritidis infections associated with eggs occurred in French Polynesia during 2008–2013. Molecular analysis of isolates by using clustered regularly interspaced short palindromic repeat polymorphisms and multilocus variable-number tandem-repeat analysis was performed. This subtyping made defining the epidemic strain, finding the source, and decontaminating affected poultry flocks possible.     

Domestically acquired Campylobacter infections in Finland

Campylobacter jejuni isolates (n = 533) from domestic cases diagnosed in Finland during a 3-month peak period were studied. The highest rate was observed among those 70-74 years of age. Domestic C. jejuni isolates were especially frequent in the eastern districts. Six serotypes covered 61% of all C. jejuni isolates.     

Extended-Spectrum β-Lactamase–producing Enterobacteriaceae among Travelers from the Netherlands

A prospective cohort study was performed among travelers from the Netherlands to investigate the acquisition of carbapenemase-producing Enterobacteriaceae (CP-E) and extended-spectrum β-lactamase–producing Enterobacteriaceae (ESBL-E) and associated risk factors. Questionnaires were administered and rectal swab samples were collected and tested before and after traveler return. Of 370 travelers, 32 (8.6%) were colonized with ESBL-E before trave,; 113 (30.5%) acquired an ESBL-E during travel, and 26 were still colonized 6 months after return. No CP-E were found. Independent risk factors for ESBL-E acquisition were travel to South and East Asia. Multilocus sequence typing showed extensive genetic diversity among Escherichia coli. Predominant ESBLs were CTX-M enzymes. The acquisition rate, 30.5%, of ESBL-E in travelers from the Netherlands to all destinations studied was high. Active surveillance for ESBL-E and CP-E and contact isolation precautions may be recommended at admission to medical facilities for patients who traveled to Asia during the previous 6 months.     

Life-threatening infantile diarrhea from fluoroquinolone-resistant Salmonella enterica typhimurium with mutations in both gyrA and parC

Salmonella Typhimurium DT12, isolated from a 35-day-old infant with diarrhea, was highly resistant to ampicillin, tetracycline, chloramphenicol, streptomycin, gentamycin, sulfamethoxazole/trimethoprim, nalidixic acid, and fluoroquinolones. The patient responded to antibiotic therapy with fosfomycin. Multidrug-resistance may become prevalent in Salmonella infections in Japan, as shown in this first case of a patient infected with fluoroquinolone-resistant Salmonella.     

Conjugated linoleic acid alters caveolae phospholipid fatty acid composition and decreases caveolin-1 expression in MCF-7 breast cancer cells

Conjugated linoleic acid (CLA) refers to a group of biologically active fatty acids that exhibit anticarcinogenic properties; however, the mechanism of action remains poorly understood. Caveolae are specialized plasma membrane structures that affect many facets of cancer cell function, including growth, cell signaling, and apoptosis. Therefore, one potential mechanism could be alteration of caveolae lipid composition and function. We hypothesized that CLA can alter the lipid microenvironment of caveolae and alter expression of the major caveolae-resident protein, caveolin-1. MCF-7 human breast cancer cells were treated with a vehicle control, linoleic acid (LA), or CLA for 3 days after which total cell lysate, plasma membrane, and caveolae membrane fractions were isolated. Our findings indicate that CLA readily incorporates into caveolae (Δ9cis,11trans-18:2 being the major isomer) and maybe preferentially enriched in specific phospholipid species. Furthermore, caveolin-1 localization to caveolae after treatment with CLA was decreased relative to either control- or LA-treated cells, without changes in total cellular levels of protein relative to vehicle-control treated cells. Taken together, our results suggest that further investigation of a potential therapeutic role for CLA in modulating caveolae function in breast cancer is merited.     

Early-Life Exposure to Outdoor Air Pollution and Respiratory Health,Ear Infections,and Eczema in Infants from the INMA Study

Background: Prenatal and early-life periods may be critical windows for harmful effects of air pollution on infant health.Objectives: We studied the association of air pollution exposure during pregnancy and the first year of life with respiratory illnesses, ear infections, and eczema during the first 12–18 months of age in a Spanish birth cohort of 2,199 infants.Methods: We obtained parentally reported information on doctor-diagnosed lower respiratory tract infections (LRTI) and parental reports of wheezing, eczema, and ear infections. We estimated individual exposures to nitrogen dioxide (NO₂) and benzene with temporally adjusted land use regression models. We used log-binomial regression models and a combined random-effects meta-analysis to estimate the effects of air pollution exposure on health outcomes across the four study locations.Results: A 10-µg/m³ increase in average NO₂ during pregnancy was associated with LRTI [relative risk (RR) = 1.05; 95% CI: 0.98, 1.12] and ear infections (RR = 1.18; 95% CI: 0.98, 1.41). The RRs for an interquartile range (IQR) increase in NO₂ were 1.08 (95% CI: 0.97, 1.21) for LRTI and 1.31 (95% CI: 0.97, 1.76) for ear infections. Compared with NO₂, the association for an IQR increase in average benzene exposure was similar for LRTI (RR = 1.06; 95% CI: 0.94, 1.19) and slightly lower for ear infections (RR = 1.17; 95% CI: 0.93, 1.46). Associations were slightly stronger among infants whose mothers spent more time at home during pregnancy. Air pollution exposure during the first year was highly correlated with prenatal exposure, so we were unable to discern the relative importance of each exposure period.Conclusions: Our findings support the hypothesis that early-life exposure to ambient air pollution may increase the risk of upper and lower respiratory tract infections in infants.     

Accelerated Mammary Tumor Onset in a HER2/Neu Mouse Model Exposed to DDT Metabolites Locally Delivered to the Mammary Gland

Background: The association of DDT (dichlorodiphenyltrichloroethane) with breast cancer is controversial, but animal studies directly linking DDT to risk are lacking. Concerns with DDT reside in its environmental persistence, bioaccumulation in breast adipose tissue, and endocrine-disrupting actions. Whereas most attention has been focused on estrogenic congeners, we tested the cancer-inducing potential of the antiandrogen, p,p′-DDE [1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene], the most prevalent and persistent DDT metabolite.Objectives: We aimed to determine whether developmental exposure to p,p′-DDE stored in adipose tissue surrounding the cancer-prone mammary epithelium of MMTV-Neu mice influences tumor development.Methods: For localized delivery, Elvax 40P pellets containing p,p′-DDE were implanted into the mammary fat pads of prepubertal female mice. We compared mammary tumor development with p,p′-DDE with development in response to its estrogenic isomer, o,p′-DDE [1,1-dichloro-2-(o-chlorophenyl)-2-(p-chlorophenyl) ethylene], and a mixture of both isomers.Results: p,p′-DDE implants significantly accelerated mammary tumor onset compared with vehicle Elvax implants. o,p′-DDE had similar results, but only at ≤ 10 months of age. Lipid-adjusted levels of p,p′-DDE in mammary adipose tissue and serum in young mice were within the ranges of human exposure, whereas concentrations in aged mice were low to undetectable. Exposure to a 2:1 ratio of p,p′-DDE:o,p′-DDE did not result in the younger latency observed with the individual isomers.Conclusions: p,p′-DDE exposure at concentrations relevant to human exposure accelerates mammary carcinogenesis in mice, possibly through hormonal and/or other actions. These data suggest that DDE exposure would promote, but not cause, mammary tumorigenesis. Developmental exposure in immature mammary tissue continues to affect tumor onset even after p,p′-DDE levels have declined. Future studies are needed to determine whether early exposure to p,p′-DDE correspondingly predisposes women to early-onset breast cancer.     

Glutamine reduces the expression of leukocyte integrins leukocyte function–associated antigen-1 and macrophage antigen-1 in mice exposed to arsenic

Chronic arsenic exposure results in an increased oxidative stress and inflammation in the body. Glutamine (GLN) is an amino acid considered to have immunomodulatory effects and attenuate the inflammatory reaction. This study was designed to examine the effect of GLN supplementation on inflammatory-related leukocyte integrin expression and in vitro splenocyte cytokine production in mice exposed to arsenic. Mice were assigned to the control and experimental groups. The control group drank deionized water, whereas the experimental group drank deionized water containing 50 ppm of sodium arsenite. Each control and experimental group was further divided into 2 subgroups and fed diets for 5 weeks. One subgroup was fed a semipurified diet, whereas the other subgroup was fed a diet where part of the casein was replaced with GLN, which provided 25% of the total amino acid nitrogen. The results showed that plasma GLN levels of mice in the arsenic group were significantly lower than those in the control groups. Glutamine supplementation reversed the depletion of plasma GLN in the arsenic group. β₂ intergins, including leukocyte function–associated antigen-1 and macrophage antigen-1 expressed by leukocytes, were significantly higher in the arsenic group than the control groups. Glutamine supplementation reduced leukocyte integrin expression in mice exposed to arsenic. There were no differences in interleukin 4, interleukin 6, interferon γ, and tumor necrosis factor α production between the 2 arsenic groups when splenocytes were stimulated with mitogen. These results suggest that arsenic exposure results in depletion of plasma GLN and higher leukocyte integrin expression. Glutamine supplementation normalized the plasma GLN levels and reduced leukocyte leukocyte function–associated antigen-1 and macrophage antigen-1 expression. However, cytokine modulation may not be responsible for reducing leukocyte integrin expression in mice exposed to arsenic.     

Isolation of a novel gene from Photobacterium damselae subsp. piscicida and analysis of the recombinant antigen as promising vaccine candidate

Photobacterium damselae subsp. piscicida (PDP) is the causative agent of fish pasteurellosis, a bacterial disease causing important losses in marine aquaculture. Vaccines against the pathogen can be a way to control the infection and avoid antibiotic treatments. However, a satisfactory protective vaccine against fish pasteurellosis is not commercially available. In this study, a biotechnogical approach based on reverse vaccinology has been used to identify potential vaccine candidates for the development of a recombinant subunit vaccine. Genome sequencing of clones from a genomic cosmid library of PDP and in silico selection of the surface exposed proteins were the initial steps in vaccine candidate identification. From 370 open reading frames (ORF) eight potential antigens were selected, expressed as recombinant proteins and purified. These vaccine candidates were used to generate specific polyclonal antibodies in mice. Each antibody was then screened in vitro by inhibition adherence assay of live PDP on chinook salmon embryo cells (CHSE-214). A lipoprotein, found to be involved in the adherence of the bacterium to epithelial cells and annotated as PDP_0080, was then selected. The recombinant protein was further investigated in fish vaccination and challenge experiments to assess its ability to protect sea bass, Dicentrarchus labrax, against PDP infection. Immunisation with PDP_0080 recombinant protein elicited high specific antibody titres. Furthermore, the survival rate of fish immunized with the 25 μg dose of protein was significantly higher compared to the control group. The results of the study suggest that the PDP_0080 protein could be a promising candidate for the design of a recombinant vaccine against pasteurellosis.     

Conjugated linoleic acid is related to bone mineral density but does not affect parathyroid hormone in men

The relationships between conjugated linoleic acid (CLA) status, bone, body composition, and the effect of CLA on calciotropic hormones are unclear. A cross-sectional study was designed to examine the association between c9, t11 CLA status in erythrocyte membranes (RBC) and body composition. This preceded a dose-response trial investigating if c9, t11 CLA affected parathyroid hormone (PTH). It was hypothesized that (1) higher c9, t11 CLA status in RBC will be associated with a lower fat and higher bone mass and that (2) PTH will be reduced by 30% after supplementation of c9, t11 CLA. Fifty-four men (age, 19-53 years) were included in the cross-sectional analysis, of which 31 were studied in the dose-response trial and randomized to 1 of 3 groups: placebo (n = 10), 1.5 g/d (n = 11), or 3.0 g/d (n = 10) of c9, t11 CLA for 16 weeks. Men with RBC c9, t11 CLA status above the median had higher whole body bone mineral density (BMD) (1.359 ± 0.024 vs 1.287 ± 0.023 g/cm²; P = .04) and whole body lean mass (WBL) percentage (78.8% ± 0.9% vs 75.3% ± 1.0%; P = .01), whereas body mass index (24.8 ± 0.5 kg/m² vs 27.3 ± 0.9 kg/m²; P = .01) and whole body fat mass percentage (17.3% ± 0.9% vs 21.3% ± 1.1%; P = .007) were lower. In regression analysis, RBC c9, t11 CLA status accounted for a significant proportion (r² = 0.10) of the variation in whole body BMD (P = .03). There were no time or treatment differences among any bone or biomarkers of bone metabolism including PTH. These findings indicate that RBC c9, t11 CLA status, a reflection of long-term (~4 months) dietary CLA intake, positively relates to BMD. However, c9, t11 CLA supplementation does not appear to affect PTH in healthy men.