Details about the members of the Indian Listeria Consortium are provided in the Supplementary Data.Emerging Microbes and Infections (2016) 5, e55; doi:10.1038/emi.2016.55; published online 8 June 2016
Listeria monocytogenes isolates (n = 36) recovered from human and animal clinical cases and foods from different geographical regions of India were characterized using multiplex PCR-based serotyping, ...pulsed field gel electrophoresis (PFGE), in vitro and in vivo pathogenicity tests and antibiogram profiling. Multiplex PCR-based serotyping distributed L. monocytogenes isolates into 3 serogroups, of which 91.67% belonged to 4b, 4d, 4e serogroup, followed by 5.56% to 1/2a, 3a and 2.78% to 1/2b, 3b serogroups. PFGE analysis using ApaI and AscI restriction enzymes revealed 17 pulsotypes among 36 L. monocytogenes isolates with 6 major clusters having similar fingerprint profile within their cluster and 11 unique fingerprint profiles. Interestingly, PFGE analysis inferred that foods of animal origin could be a significant source of infection for spread of listeriosis among human populations. Furthermore, on comparison of in vitro and in vivo pathogenicity tests, an overall good correlation was observed between hemolytic titer assay and chick embryo inoculation test as most of the isolates with a hemolytic titer of ≥16 were found to be lethal to chick embryo. All the isolates were found to be susceptible to tested antimicrobials except for one animal isolate which showed resistance towards co-trimoxazole.
Comparison and characterization of L. monocytogenes from different sources.
Francisella tularensis is a category A biothreat agent for which there is no approved vaccine and the correlates of protection are not well understood. In particular, the relationship between the ...humoral and cellular immune response to F. tularensis and the relative importance of each in protection is controversial. Yet, understanding this relationship will be crucial to the development of an effective vaccine against this organism. We demonstrate, for the first time, a differential requirement for humoral vs cellular immunity in vaccine-induced protection against F. tularensis infection, and that the requirement for Ab observed in some protection studies, may be overcome through the induction of enhanced cellular immunity. Specifically, following intranasal/mucosal immunization of mice with inactivated F. tularensis organisms plus the cholera toxin B subunit, we observe increased production of IgG2a/2c vs IgG1 Ab, as well as IFN-gamma, indicating induction of a Th1 response. In addition, the requirement for F. tularensis-specific IgA Ab production, observed in studies following immunization with inactivated F. tularensis alone, is eliminated. Thus, these data indicate that enhanced Th1 responses can supersede the requirement for anti-F. tularensis-specific IgA. This observation also has important ramifications for vaccine development against this organism.
The present study describes the utility of a chromosomal associated fimbrial subunit gene (fimA) for screening ‘typical’ as well as ‘atypical’ Enteroaggregative Escherichia coli (EAEC) by PCR and its ...possible role as a promising molecular marker for rapid detection of ‘typical’ and ‘atypical’ EAEC pathotype.
We report a novel, rapid, economical and species-specific DNA-based assay for the authentication of pork. The technique specifically amplified porcine mitochondrial D loop region by combining ...Alkaline Lysis (AL) method of DNA extraction and Loop Mediated Isothermal Amplification (LAMP). Visual detection of the reaction was accomplished by color development in the reaction with the addition of SYBR Green I dye. Dependable amplification was possible in thermally processed meat samples heated up to 121 °C for 30 min. The assay was able to detect pork in beef up to the level of 0.1% admixture and limit of detection of DNA was at 0.5 ng/μL. Cross-amplification of related species like cattle, buffalo, sheep, goat and chicken was excluded by incorporating their DNA in the reaction assay. The novel approach (AL-LAMP technique) was found to be robust and handy, suitable even for resource compromised laboratories engaged in the food analysis.
•Manuscript reports a rapid technique for the species identification of pork.•Technique uses Alkaline lysis method for the extraction of DNA.•Target DNA was amplified using novel pork specific LAMP primers.•Results can be visualized by colour changes after the addition of SYBR Green I dye.•AL-LAMP assay has potential to be used at field level for pork authentication.
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•Generated nano ZIF-8(Fe) using two distinct metal clusters.•Synthesized ZIF-8(Fe) was characterised to sodalite topology.•ZIF-8(Fe) could degrade MB and RhB dyes under visible ...light.•Photocatalytic rate of MB was substantially higher thanRhB.
Metal-organic framework (MOF) is a promising material constructed using metal clusters and organic linkers; Zeolite imidazole frameworks are one such subclass of MOFs with zeolite topology. In this study, the authors have successfully synthesized a modified zeolite imidazole framework (ZIF-8(Fe)) in the aqueous solvent. ZIF-8(Fe) nanoparticle synthesis was confirmed by infrared spectral measurements, and the surface plasmon resonance (SPR) was determined to be 215 nm. Additionally, the PXRD pattern verified the synthesis of ZIF-8(Fe) with a sod-like structure that sized consistently at 36.10 nm.Scanning electron microscopic analysis revealed MOF with regular spherical morphology. Further, ZIF-8(Fe) can be considered an efficient photocatalyst for the degradation of methylene blue (MB) and rhodamine-B (RhB) when exposed to visible radiation. In comparison to RhB, the photocatalytic results show that ZIF-8(Fe) enhances and significantly improves MB degradation.
The global emergence of antimicrobial resistance (AMR) needs no emphasis. In this study, the in vitro stability, safety, and antimicrobial efficacy of nanosilver-entrapped cinnamaldehyde (AgC) ...against multi-drug-resistant (MDR) strains of enteroaggregative Escherichia coli (EAEC) were investigated. Further, the in vivo antibacterial efficacy of AgC against MDR-EAEC was also assessed in Galleria mellonella larval model. In brief, UV-Vis and Fourier transform infrared (FTIR) spectroscopy confirmed effective entrapment of cinnamaldehyde with nanosilver, and the loading efficiency was estimated to be 29.50 ± 0.56%. The AgC was of crystalline form as determined by the X-ray diffractogram with a mono-dispersed spherical morphology of 9.243 ± 1.83 nm in electron microscopy. AgC exhibited a minimum inhibitory concentration (MIC) of 0.008–0.016 mg/mL and a minimum bactericidal concentration (MBC) of 0.008–0.032 mg/mL against MDR- EAEC strains. Furthermore, AgC was stable (high-end temperatures, proteases, cationic salts, pH, and host sera) and tested safe for sheep erythrocytes as well as secondary cell lines (RAW 264.7 and HEp-2) with no negative effects on the commensal gut lactobacilli. in vitro, time-kill assays revealed that MBC levels of AgC could eliminate MDR-EAEC infection in 120 min. In G. mellonella larvae, AgC (MBC values) increased survival, decreased MDR-EAEC counts (p < 0.001), had an enhanced immunomodulatory effect, and was tested safe to the host. These findings infer that entrapment enhanced the efficacy of cinnamaldehyde and AgNPs, overcoming their limitations when used individually, indicating AgC as a promising alternative antimicrobial candidate. However, further investigation in appropriate animal models is required to declare its application against MDR pathogens.
Coxiella burnetii is a highly infectious zoonotic pathogen infecting wide range of mammals, including humans. In the present study, a total of 711 blood samples from bovines cattle (n = 543) and ...buffaloes (n = 168) from eight farms at different geographical locations in India were screened for C. burnetii targeting the IS1111 and the com1 genes. The anti-C. burnetii antibodies in serum samples were detected using indirect-ELISA kits. Also, a total of 21 parameters pertaining to animal health and farm management were identified to assess their role as possible risk factors for coxiellosis among the targeted farms. The apparent prevalence (positive for PCR and/or ELISA) for coxiellosis was reported to be 24.5% in cattle and 8.9% in buffaloes. In cattle, the detection rate of C. burnetii employing the IS1111 gene (8.5%) was found to be significantly higher (p<0.05) as compared to the com1 (6.5%) gene. The seropositivity by ELISA was higher among cattle (17.7%) than in buffaloes (8.3%). Further, on univariable analysis of risk factors, species (cattle) (OR:3.31; 95%CI:1.88–5.82), inadequate floor spacing (OR:1.64; 95%CI:1.10–2.43), mastitis (OR:2.35, 95%CI:1.45–3.81) and reproductive disorders (OR:2.54; 95%CI:1.67–3.85) were significantly (p<0.05) having high odds for coxiellosis. The multivariable logistic regression analysis of the animal level risk factors revealed that species and age were found to be significantly associated with coxiellosis. However, since the number of screened farms is limited; further research is needed with a higher number of animals to confirm the farm level odds ratio of risk factors. Quarantine and biosecurity measures including farm hygiene operations were observed to be inadequate and also the lack of awareness about coxiellosis among the farm workers. In absence of vaccination program for coxiellosis in India, robust surveillance, farm biosecurity measures and the awareness for the disease among risk groups can play an important role in the disease prevention and subsequent transmission of the pathogen.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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