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1.
Exp Parasitol ; 254: 108621, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37722650

RESUMO

Canine babesiosis, caused by Babesia gibsoni is one of the most significant tick-borne illnesses across the world. Light microscopy as well as polymerase chain reaction may fail in the diagnosis of disease when the level of parasitaemia is very low during subclinical and chronic cases. The serological techniques using a recombinant protein will be useful for the accurate and sensitive surveillance of the disease, especially in chronic cases. The present study describes the evaluation of recombinant N-terminal B. gibsoni Thrombospondin-related adhesive protein (BgTRAP) based indirect ELISA for the sero-diagnosis of B. gibsoni infection in dogs. A partial N-terminal BgTRAP gene (870 bp) of B. gibsoni, was expressed in Escherichia coli using a pET32a (+) vector. The recombinant BgTRAP based indirect ELISA was compared with the PCR targeting the same gene. A sensitivity and a specificity of 84% and 73.33% were observed in the indirect ELISA. The accuracy, positive predictive value and negative predictive value were 78.18%, 72.30%, 84.60% respectively. The rBgTRAP antigen did not show any cross-reactivity with sera from dogs infected with common helminth parasites viz. Ancylostoma caninum, Dirofilaria immitis, D. repens, Spirometra spp., Toxocara canis and haemoparasites like Trypanosoma evansi, Babesia vogeli, Hepatozoon canis and Ehrlichia canis.

2.
Trop Anim Health Prod ; 55(2): 126, 2023 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-36944831

RESUMO

Fowl typhoid (FT) is an economically significant bacterial disease of layers leading to a drastic drop in egg production. Due to increased public health concerns about antibiotics in poultry feed, a search for new safe antimicrobials for treating fowl typhoid is crucial. The antimicrobial effect of cinnamaldehyde essential oil (CnEO) against fowl typhoid in layers was investigated in this experiment. The 60-week-old BV300-layer birds (n = 100) were divided into five groups: the non-challenged control group A, only cinnamaldehyde-treated group B (CnEO @ 1:8000 dilutions through drinking water for 60 days), the challenged group C, challenged plus cinnamaldehyde therapy group D (CnEO @ 1:8000 dilutions through drinking water from 16 to 30 dpi), and challenged plus antibiotic therapy group E (chloramphenicol @ 1 gm/5lit through drinking water from 16 to 30 dpi). Hens from all challenged groups were challenged with Salmonella Gallinarum (VTCCBAA588) @ 1 × 108 CFU/ml orally. Various parameters such as clinical signs, mortality, egg production and egg weight, colony-forming unit (CFU) count of cecal content, eggshell surface, and egg yolk were evaluated all through 60 days of an experimental trial. Results indicated that, in the case of the cinnamaldehyde therapeutic group, there was a significant improvement in egg production, mild clinical signs, lower feed conversion ratio (FCR), and a significantly lower bacterial count in ceca and on the eggshell surface compared to the control challenge group. Thus, CnEO @ 1:8000 dilutions through drinking water can be a potential antimicrobial for controlling fowl typhoid.


Assuntos
Anti-Infecciosos , Água Potável , Óleos Voláteis , Doenças das Aves Domésticas , Salmonelose Animal , Febre Tifoide , Animais , Feminino , Óleos Voláteis/farmacologia , Óleos Voláteis/uso terapêutico , Febre Tifoide/microbiologia , Febre Tifoide/veterinária , Galinhas , Doenças das Aves Domésticas/tratamento farmacológico , Doenças das Aves Domésticas/prevenção & controle , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Óvulo
3.
Environ Microbiol ; 24(6): 2759-2780, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34693631

RESUMO

Listeria monocytogenes, the causative agent of listeriosis, has been implicated in increasing foodborne outbreaks worldwide. The disease is manifested in various forms ranging from severe sepsis in immune-compromised individuals, febrile gastroenteritis, still birth, abortions and meningoencephalitis. In India, data from studies on the detection and molecular epidemiological analysis of L. monocytogenes are only recently emerging. The presence of Listeria in different ecological niches has been recorded from India, including foods, soil, vegetables, mangrove swamps, seafood, freshwater fishes, clinical cases, and also insects. The organism has also been isolated from women with spontaneous abortions, miscarriage or recurrent obstetric history, aborted foetuses, animal clinical cases and wildlife samples. A novel species of Listeria has also been characterized. Listeria monocytogenes strains isolated from clinical, environmental, and foods showed biofilm-forming abilities. Listeria monocytogenes serotype 4b isolates of ST328, a predominant and unique ST observed in India, was repeatedly isolated from different sources, times, and geographical locations. Here, we reviewed the occurrence of Listeria in different sources in India, its resistance to biocides, and provide epidemiological analysis on its genomic landscape.


Assuntos
Desinfetantes , Listeria monocytogenes , Listeria , Listeriose , Animais , Farmacorresistência Bacteriana , Feminino , Microbiologia de Alimentos , Genômica , Humanos , Índia/epidemiologia , Listeriose/epidemiologia , Gravidez
4.
Environ Microbiol ; 24(6): 2747-2758, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34528343

RESUMO

The in vitro antibacterial efficacy of an in-house designed cell-penetrating peptide (CPP) variant of Cecropin A (1-7)-Melittin (CAMA) (CAMA-CPP) against the characterized multi-drug resistant (MDR) field strains of Salmonella Enteritidis and Salmonella Typhimurium were evaluated and compared with two identified CPPs namely, P7 and APP, keeping CAMA as control. Initially, the minimum inhibitory concentration (MIC) (µg ml-1 ) of in-house designed CAMA-CPP, APP and CAMA was determined to be 3.91, whereas that of P7 was 7.81; however, the minimum bactericidal concentration (MBC) of all the peptides were twice the MIC. CAMA-CPP and CAMA were found to be stable under different conditions (high-end temperatures, proteinase-K, cationic salts, pH and serum) when compared to the other CPPs. Moreover, CAMA-CPP exhibited negligible cytotoxicity in HEp-2 and RAW 264.7 cell lines as well as haemolysis in the sheep and human erythrocytes with no adverse effects against the commensal gut lactobacilli. In vitro time-kill assay revealed that the MBC levels of CAMA-CPP and APP could eliminate the intracellular MDR-Salmonella infections from mammalian cell lines; however, CAMA and P7 peptides were ineffective. CAMA-CPP appears to be a promising antimicrobial candidate and opens up further avenues for its in vivo clinical translation.


Assuntos
Antibacterianos , Peptídeos Penetradores de Células , Farmacorresistência Bacteriana Múltipla , Salmonella enteritidis , Salmonella typhimurium , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Linhagem Celular , Peptídeos Penetradores de Células/química , Peptídeos Penetradores de Células/farmacologia , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Células RAW 264.7 , Salmonella enteritidis/efeitos dos fármacos , Salmonella typhimurium/efeitos dos fármacos , Ovinos
5.
Indian J Med Res ; 153(3): 348-357, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33906998

RESUMO

Fisheries comprise the fastest growing sector meeting the global protein requirements. Being an affordable enterprise, it is considered a safe source of food and the muscles of healthy fishes are almost sterile. However, a multitude of hazards (biological, chemical, and environmental) can be introduced into aquaculture throughout the production and supply chain. Also, it can originate from unsuitable farming practices, environmental pollution, and socio-cultural habits prevailing in various regions. Hence, with an increasing global population and demands for aquacultural products, assessment and regulation of food safety concerns are becoming significantly evident. Ensuring safe, secure, affordable, and quality food for all in a global context is pragmatically difficult. In this context, it is quite imperative to understand the ecology and dynamics of these hazards throughout the entire production chain in a One Health approach. Here, we discuss the issues and challenges faced in the fisheries sector as a whole and the need for a One Health approach to overcome such hurdles.


Assuntos
Pesqueiros , Saúde Única , Animais , Aquicultura , Inocuidade dos Alimentos , Abastecimento de Alimentos , Humanos
6.
Microb Pathog ; 147: 104405, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32707313

RESUMO

The present study evaluated intracellular antibacterial efficacy of two short-chain cationic antimicrobial peptides (AMPs) namely, Cecropin A (1-7)-Melittin and lactoferricin (17-30) against three field strains of multi-drug resistant Salmonella Enteritidis. Initially, antimicrobial ability of both the AMPs was evaluated for their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against multi-drug resistant S. Enteritidis strains. Besides, the AMPs were evaluated for its in vitro stability (high-end temperatures, proteases, physiological concentrations of cationic salts and pH) and safety (haemolytic assay in sheep erythrocytes; cytotoxicity assay in murine macrophage RAW 264.7 cell line and human epithelioma HEp-2 cell line and beneficial gut lactobacilli). Later, a time-kill assay was performed to assess the intracellular antibacterial activity of Cecropin A (1-7)-Melittin and lactoferricin (17-30) against multi-drug resistant S. Enteritidis in RAW 264.7 and HEp-2 cells. The observed MBC values of Cecropin A (1-7)-Melittin and lactoferricin (17-30) against multi-drug resistant S. Enteritidis (128 µM; 256 µM) were generally twice or four-fold greater than the MIC values (64 µM). Further, both the AMPs were found variably stable after exposure at high-end temperatures (70 °C and 90 °C), protease treatment (trypsin, proteinase K, lysozyme), higher concentration of physiological salts (150 mM NaCl and 2 mM MgCl2) and hydrogen ion concentrations (pH 4.0 to 8.0). Both the AMPs were found non-haemolytic on sheep erythrocytes, revealed minimal cytotoxicity in RAW 264.7 and HEp-2 cells, and was tested safe against beneficial gut lactobacilli (L. acidophilus and L. rhamnosus). Intracellular bacteriostatic effect with both cationic AMPs against multi-drug resistant S. Enteritidis was evident in RAW 264.7 cells; however, in both the cell lines, the significant bactericidal effect was not observed (P > 0.05) with both cationic AMPs understudy against multi-drug resistant S. Enteritidis. Based on the results of the present study, both the cationic AMPs understudy may not be useful for the intracellular elimination of multi-drug resistant S. Enteritidis; hence, further studies such as conjugation of these AMPs with either cell-penetrating peptides (CPP) and/or nanoparticles (NPs) are warranted.


Assuntos
Antibacterianos , Anti-Infecciosos , Peptídeos Catiônicos Antimicrobianos , Meliteno , Preparações Farmacêuticas , Infecções por Salmonella , Animais , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Resistência a Múltiplos Medicamentos , Lactoferrina , Meliteno/farmacologia , Camundongos , Testes de Sensibilidade Microbiana , Fragmentos de Peptídeos , Infecções por Salmonella/tratamento farmacológico , Salmonella enteritidis , Ovinos
7.
Foodborne Pathog Dis ; 16(3): 214-220, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30632791

RESUMO

OBJECTIVES: The occurrence of Listeria monocytogenes was studied by using cultural and serological methods in cattle housed in a particular gaushala (cattle shelter) and organized dairy farm. MATERIALS AND METHODS: A total of 1201 samples from cattle comprising blood (n = 207), milk (n = 203), vaginal swabs (n = 210), and serum (n = 207) from an organized farm (n = 210) and blood (n = 100), milk (n = 74), vaginal swabs (n = 100), and serum (n = 100) from a gaushala (n = 100) were collected and analyzed for L. monocytogenes. All samples excluding serum were analyzed for isolation and identification of L. monocytogenes, while the serum samples were screened for seropositivity. The isolates were further subjected to assess their virulence potential (in vitro and in vivo), biofilm formation ability, and antibiotic susceptibility patterns. RESULTS: Four L. monocytogenes strains were isolated from the cattle; three (0.48%) from the organized farm and one (0.36%) from the gaushala. On serological screening of cattle from the organized dairy farm, 16.42% were found to be positive for antibodies against listeriolysin O, while cattle from the gaushala revealed 36% seropositivity. Furthermore, on characterization of the isolates for their pathogenic potential and biofilm-forming ability, all were found to be pathogenic by both in vitro and in vivo assays and were weak to moderate biofilm formers. The minimum inhibition concentration (MIC) of recovered isolates revealed resistance for ampicillin by two L. monocytogenes isolates (MIC >256 µg/mL), whereas three L. monocytogenes isolates were intermediately resistant (MIC >4 µg/mL) and one resistant against amoxicillin (MIC >8 µg/mL). However, all four isolates were susceptible to gentamicin, cotrimoxazole, and erythromycin. CONCLUSIONS: Isolation of virulent and antibiotic-resistant strains of L. monocytogenes warrants the need for epidemiological surveillance, antimicrobial susceptibility, and implementation of control measures to combat the occurrence of L. monocytogenes infection in animals as well as humans.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Listeria monocytogenes/efeitos dos fármacos , Listeriose/veterinária , Virulência , Animais , Bovinos , Contagem de Colônia Microbiana/veterinária , Indústria de Laticínios , Fazendas , Feminino , Índia , Listeria monocytogenes/genética , Listeria monocytogenes/isolamento & purificação , Listeriose/tratamento farmacológico , Testes de Sensibilidade Microbiana/veterinária , Leite
8.
Crit Rev Food Sci Nutr ; 55(10): 1315-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24915322

RESUMO

Achieving food safety is a global health goal and the food-borne diseases take a major check on global health. Therefore, detection of microbial pathogens in food is the solution to the prevention and recognition of problems related to health and safety. Conventional and standard bacterial detection methods such as culture and colony counting methods and immunology-based methods may take up to several hours or even a few days to yield a result. Obviously, this is inadequate, and recently many researchers are focusing towards the progress of rapid diagnostic methods. The advent of molecular techniques has led to the development of a diverse array of assay for quality control of meat and meat products. Rapid analysis using DNA hybridization and amplification techniques offer more sensitivity and specificity to get results than culture based methods as well as dramatic reduction in the time to get results. Many methods have also achieved the high level automation, facilitating their application as routine sample screening assays. This review is intended to provide an overview of the molecular methods for microbiological quality control of meat and meat products.


Assuntos
DNA/análise , Contaminação de Alimentos/análise , Produtos da Carne/análise , Carne/microbiologia , Hibridização de Ácido Nucleico/métodos , Animais , Microbiologia de Alimentos/métodos , Carne/análise , Controle de Qualidade
9.
Crit Rev Food Sci Nutr ; 55(10): 1320-3, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24915323

RESUMO

Food-borne illnesses pose a real scourge in the present scenario as the consumerism of packaged food has increased to a great extend. Pathogens entering the packaged foods may survive longer, which needs a check. Antimicrobial agents either alone or in combination are added to the food or packaging materials for this purpose. Exploiting the antimicrobial property, essential oils are considered as a "natural" remedy to this problem other than its flavoring property instead of using synthetic agents. The essential oils are well known for its antibacterial, antiviral, antimycotic, antiparasitic, and antioxidant properties due to the presence of phenolic functional group. Gram-positive organisms are found more susceptible to the action of the essential oils. Essential oils improve the shelf-life of packaged products, control the microbial growth, and unriddle the consumer concerns regarding the use of chemical preservatives. This review is intended to provide an overview of the essential oils and their role as natural antimicrobial agents in the food industry.


Assuntos
Anti-Infecciosos/farmacologia , Contaminação de Alimentos/prevenção & controle , Indústria Alimentícia/métodos , Microbiologia de Alimentos , Conservantes de Alimentos/farmacologia , Óleos Voláteis/farmacologia , Anti-Infecciosos/análise , Conservantes de Alimentos/química , Humanos , Óleos Voláteis/análise
10.
Comp Immunol Microbiol Infect Dis ; 93: 101929, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36580799

RESUMO

A total of 38 Escherichia coli isolates were recovered from 120 samples collected from various sources of broiler chicken farms (n = 10 each) in Andhra Pradesh and Telangana states. Though the recovered E. coli isolates were found variably resistant to the tested antibiotics, all the tested isolates were susceptible to meropenem. Alarming multi-drug resistance (MDR) was observed (34/38) among the recovered isolates, wherein antibiotic-resistant genes (blaTEM, blaSHV, and tetA) were detected, except for blaCTX-M-9. The heatmap with cluster analysis exhibited that majority of the E. coli isolates recovered from different sources and regions clustered together based on their phenotypic resistance suggesting co-sharing of resistance. However, the pulsed-field gel electrophoresis (PFGE) typing revealed an extremely diverse genotypic profile. Further, a significant statistical association was not observed between hypothesized risk factors and recovered MDR- E. coli isolates from various sources, although a significant statistical association between antibiotic resistance with large flock size, poor biosecurity practices, poor workers' hygiene, and poor disinfection practices was noticed. Since the study highlighted an alarming level of drug resistance among the recovered E. coli isolates, further in-depth research in similar veins is required to ensure the prudent use of antimicrobials in the poultry sector and the implementation of an antimicrobial surveillance system.


Assuntos
Infecções por Escherichia coli , Escherichia coli , Animais , Galinhas , Fazendas , Antibacterianos/farmacologia , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/veterinária , Fatores de Risco , Variação Genética , beta-Lactamases/genética
11.
Probiotics Antimicrob Proteins ; 14(5): 904-914, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35715714

RESUMO

The present study was envisaged to employ the green synthesis and characterization of silver nanoparticles (AgNPs) using the potential probiotic strain Lactobacillus acidophilus, to assess its antibacterial as well as antibiofilm activity against multi-drug-resistant enteroaggregative Escherichia coli (MDR-EAEC) strains and to investigate their antioxidant activity. In this study, AgNPs were successfully synthesized through an eco-friendly protocol, which was then confirmed by its X-ray diffraction (XRD) pattern. A weight loss of 15% up to 182 °C with a narrow exothermic peak between 170 °C and 205 °C was observed in thermogravimetric analysis-differential thermal analysis (TGA-DTA), while aggregated nanoclusters were observed in scanning electron microscopy (SEM). Moreover, the transmission electron microscopy (TEM) imaging of AgNPs revealed a spherical morphology and crystalline nature with an optimum size ranging from 10 to 20 nm. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of green synthesized AgNPs against the MDR-EAEC strains were found to be 7.80 mg/L and 15.60 mg/L, respectively. In vitro time-kill kinetic assay revealed a complete elimination of the MDR-EAEC strains after 180 min on co-incubation with the AgNPs. Moreover, the green synthesized AgNPs were found safe by in vitro haemolytic assay. Besides, the green synthesized AgNPs exhibited significant biofilm inhibition (P < 0.001) formed by MDR-EAEC strains. Additionally, a concentration-dependent antioxidant activity was observed in 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. Hence, this study demonstrated potential antibacterial as well as antibiofilm activity of green synthesized AgNPs against MDR-EAEC strains with antioxidant properties and warrants further in-depth studies to explore it as an effective antimicrobial agent against MDR infections.


Assuntos
Anti-Infecciosos , Nanopartículas Metálicas , Probióticos , Antibacterianos/química , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Biofilmes , Escherichia coli , Lactobacillus acidophilus , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Prata/farmacologia
12.
Parasitol Int ; 86: 102477, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34619383

RESUMO

Babesia gibsoni, the causative agent of canine piroplasmosis, is a tick-borne intraerythrocytic protozoan parasite predominantly reported in Asian countries. The present study aimed at genotypic characterization of B. gibsoni isolates prevalent in dogs in Kerala, a southern state of India. Blood samples were collected from 272 dogs in Kerala and B. gibsoni infection was detected by microscopy and polymerase chain reaction (PCR). Molecular confirmation of B. gibsoni parasites was carried out by 18S rRNA nested-PCR, followed by sequencing. Nested-PCR detected a higher percentage of dogs (40.44%) positive for B. gibsoni infection than microscopy where 15.81% dogs were detected positive for infection. Genetic characterization of B. gibsoni isolates (n = 11) prevalent in dogs in the state of Kerala was carried out by PCR amplification and sequencing of the 855 bp thrombospondin-related adhesive protein (TRAP) gene fragment. Phylogenetic analysis of the B. gibsoni TRAP (BgTRAP) gene revealed that B. gibsoni isolates from Kerala formed a distinct cluster with the isolates from north India and Bangladesh, away from other East Asian isolates. Nucleotide analysis of the tandem repeats of BgTRAP gene showed considerable genetic variation among Indian isolates that was shared by B. gibsoni isolates of Bangladesh but not by the isolates of East Asian countries. The results of the present study further confirmed that B. gibsoni parasites in a distinct genetic clade are endemic in dogs in India and Bangladesh. However, elaborate studies are required for better understanding of the genetic diversity of B. gibsoni.


Assuntos
Babesia/isolamento & purificação , Babesiose/epidemiologia , Doenças do Cão/epidemiologia , Variação Genética , Filogenia , Animais , Babesia/genética , Babesiose/parasitologia , Doenças do Cão/parasitologia , Cães , Índia/epidemiologia , Prevalência , Proteínas de Protozoários/análise , Trombospondinas/análise
13.
Pharmaceutics ; 14(9)2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-36145672

RESUMO

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.

14.
Pathog Dis ; 79(3)2021 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-33512501

RESUMO

High throughput in vivo laboratory models is need for screening and identification of effective therapeutic agents to overcome microbial drug-resistance. This study was undertaken to evaluate in vivo antimicrobial efficacy of short-chain antimicrobial peptide- Cecropin A (1-7)-Melittin (CAMA) against three multi-drug resistant enteroaggregative Escherichia coli (MDR-EAEC) field isolates in a Galleria mellonella larval model. The minimum inhibitory concentration (MIC; 2.0 mg/L) and minimum bactericidal concentration (MBC; 4.0 mg/L) of CAMA were determined by microdilution assay. CAMA was found to be stable at high temperatures, physiological concentration of cationic salts and proteases; safe with sheep erythrocytes, secondary cell lines and commensal lactobacilli at lower MICs; and exhibited membrane permeabilization. In vitro time-kill assay revealed concentration- and time-dependent clearance of MDR-EAEC in CAMA-treated groups at 30 min. CAMA- treated G. mellonella larvae exhibited an increased survival rate, reduced MDR-EAEC counts, immunomodulatory effect and proved non-toxic which concurred with histopathological findings. CAMA exhibited either an equal or better efficacy than the tested antibiotic control, meropenem. This study highlights the possibility of G. mellonella larvae as an excellent in vivo model for investigating the host-pathogen interaction, including the efficacy of antimicrobials against MDR-EAEC strains.


Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/patologia , Escherichia coli/efeitos dos fármacos , Meliteno/farmacologia , Animais , Antibacterianos/farmacologia , Peptídeos Antimicrobianos/farmacologia , Modelos Animais de Doenças , Farmacorresistência Bacteriana Múltipla , Larva/microbiologia , Testes de Sensibilidade Microbiana , Mariposas/microbiologia , Taxa de Sobrevida
15.
Gut Pathog ; 13(1): 46, 2021 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-34273998

RESUMO

BACKGROUND: In the wake of emergence of antimicrobial resistance, bioactive phytochemical compounds are proving to be important therapeutic agents. The present study envisaged in silico molecular docking as well as in vitro antimicrobial efficacy screening of identified phytochemical ligands to the dispersin (aap) and outer membrane osmoporin (OmpC) domains of enteroaggregative Escherichia coli (EAEC) and non-typhoidal Salmonella spp. (NTS), respectively. MATERIALS AND METHODS: The evaluation of drug-likeness, molecular properties, and bioactivity of the identified phytocompounds (thymol, carvacrol, and cinnamaldehyde) was carried out using Swiss ADME, while Protox-II and StopTox servers were used to identify its toxicity. The in silico molecular docking of the phytochemical ligands with the protein motifs of dispersin (PDB ID: 2jvu) and outer membrane osmoporin (PDB ID: 3uu2) were carried out using AutoDock v.4.20. Further, the antimicrobial efficacy of these compounds against multi-drug resistant EAEC and NTS strains was determined by estimating the minimum inhibitory concentrations and minimum bactericidal concentrations. Subsequently, these phytochemicals were subjected to their safety (sheep and human erythrocytic haemolysis) as well as stability (cationic salts, and pH) assays. RESULTS: All the three identified phytochemicals ligands were found to be zero violators of Lipinski's rule of five and exhibited drug-likeness. The compounds tested were categorized as toxicity class-4 by Protox-II and were found to be non- cardiotoxic by StopTox. The docking studies employing 3D model of dispersin and ompC motifs with the identified phytochemical ligands exhibited good binding affinity. The identified phytochemical compounds were observed to be comparatively stable at different conditions (cationic salts, and pH); however, a concentration-dependent increase in the haemolytic assay was observed against sheep as well as human erythrocytes. CONCLUSIONS: In silico molecular docking studies provided useful insights to understand the interaction of phytochemical ligands with protein motifs of pathogen and should be used routinely before the wet screening of any phytochemicals for their antibacterial, stability, and safety aspects.

16.
J Microbiol Methods ; 188: 106278, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34246691

RESUMO

The present study evaluated the comparative serodiagnostic efficacy of recombinant listeriolysin-O (rLLO) and synthetic LLO- 2 peptide-based indirect ELISA vis-à-vis cultural isolation using samples (n = 1326; blood, sera, vaginal swabs, and rectal swabs) collected from caprines (n = 350) and ovines (n = 50) having reproductive and/or nervous system disorders and/or healthy animals. On screening the test sera by rLLO- based ELISA, the antibodies against LLO (ALLO) were observed in 17.71% of the caprines and 2% of the ovines, respectively, while synthetic LLO-2- based ELISA revealed ALLO in 6.86% of caprines and not in ovines. Moreover, the adsorption of positive test sera with streptolysin-O (SLO) resulted in a significant reduction (7.43%; p < 0.05) in the seropositivity with rLLO- based ELISA, whereas LLO-2- based ELISA revealed marginal reduction (4.29%; p > 0.05) in the seropositivity. Overall, the seropositivity with LLO-2 synthetic peptide revealed comparatively less cross-reactivity in comparison to rLLO. The cultural isolation yielded five pathogenic L. monocytogenes isolates and three non-pathogenic Listeria spp. from caprine samples; however, Listeria spp. could not be recovered from any of the ovine samples. Further, on comparing seropositivity with the isolation study results, it was found that two out of the five animals from which pathogenic L. monocytogenes isolated were also found seropositive in both the ELISAs even after adsorption with SLO. Interestingly, rLLO- based ELISA detected antibodies against unadsorbed caprine sera even in those samples from which non-pathogenic Listeria spp. were isolated, whereas antibodies were not detected in LLO-2 peptide-based ELISA. In conclusion, it could be inferred that the synthetic LLO-2 peptide serves as a non- cross-reactive, ideal diagnostic antigen in serodiagnosis of capro-ovine listeriosis.


Assuntos
Toxinas Bacterianas/genética , Ensaio de Imunoadsorção Enzimática/métodos , Proteínas de Choque Térmico/genética , Proteínas Hemolisinas/genética , Listeriose/diagnóstico , Peptídeos/síntese química , Peptídeos/genética , Animais , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias , Proteínas de Bactérias , Reações Cruzadas , Feminino , Doenças das Cabras/diagnóstico , Cabras , Listeria/genética , Listeria/isolamento & purificação , Listeriose/sangue , Listeriose/microbiologia , Proteínas Recombinantes , Testes Sorológicos/métodos , Ovinos , Doenças dos Ovinos/diagnóstico , Estreptolisinas
17.
Environ Microbiol Rep ; 13(2): 138-158, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33314653

RESUMO

Coxiellosis or Q fever is an important global occupational zoonotic disease caused by one of the most contagious bacterial pathogens - Coxiella burnetii, which ranks one among the 13 global priority zoonoses. The detection of C. burnetii infection is exhibiting an increasing trend in high-risk personnel around the globe. It has increasingly been detected from foods of animal origin (including bulk milk, eggs, and meat) as well as tick vectors in many parts of the world. Coxiellosis is reported to be an important public health threat causing spontaneous abortions in humans and potential reproductive failure, which would result in production losses among livestock. Further, comprehensive coverage of the reports and trends of Q fever in developing countries, where this infection is supposed to be widely prevalent appears scarce. Also, the pathogen remains grossly neglected and underreported. Moreover, policymakers and funding agencies do not view it as a priority problem, especially in the Indian subcontinent, including Sri Lanka, Bhutan, Pakistan, Nepal, Bangladesh and Maldives. Here, we review the occurrence and epidemiology of the disease in a global context with special emphasis on its status in the Indian subcontinent.


Assuntos
Coxiella burnetii , Febre Q , Animais , Febre Q/epidemiologia , Zoonoses/epidemiologia
18.
Front Microbiol ; 11: 575917, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33072040

RESUMO

The study evaluated the in vitro antimicrobial and antibiofilm efficacy of an antimicrobial peptide (AMP), lactoferricin (17-30) [Lfcin (17-30)], against biofilm-forming multi-drug-resistant (MDR) strains of enteroaggregative Escherichia coli (EAEC), and subsequently, the in vivo antimicrobial efficacy was assessed in a Galleria mellonella larval model. Initially, minimum inhibitory concentration (MIC; 32 µM), minimum bactericidal concentration (MBC; 32 µM), and minimum biofilm eradication concentration (MBEC; 32 µM) of Lfcin (17-30) were determined against MDR-EAEC field isolates (n = 3). Lfcin (17-30) was tested stable against high-end temperatures (70 and 90°C), physiological concentration of cationic salts (150 mM NaCl and 2 mM MgCl2), and proteases (proteinase-K and lysozyme). Further, at lower MIC, Lfcin (17-30) proved to be safe for sheep RBCs, secondary cell lines (HEp-2 and RAW 264.7), and beneficial gut lactobacilli. In the in vitro time-kill assay, Lfcin (17-30) inhibited the MDR-EAEC strains 3 h post-incubation, and the antibacterial effect was due to membrane permeation of Lfcin (17-30) in the inner and outer membranes of MDR-EAEC. Furthermore, in the in vivo experiments, G. mellonella larvae treated with Lfcin (17-30) exhibited an increased survival rate, lower MDR-EAEC counts (P < 0.001), mild to moderate histopathological changes, and enhanced immunomodulatory effect and were safe to larval cells when compared with infection control. Besides, Lfcin (17-30) proved to be an effective antibiofilm agent, as it inhibited and eradicated the preformed biofilm formed by MDR-EAEC strains in a significant (P < 0.05) manner both by microtiter plate assay and live/dead bacterial quantification-based confocal microscopy. We recommend further investigation of Lfcin (17-30) in an appropriate animal model before its application in target host against MDR-EAEC strains.

19.
Hum Vaccin Immunother ; 16(12): 3023-3033, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33121328

RESUMO

Severe acute respiratory syndrome Coronavirus- 2 (SARS-CoV-2), the etiological agent of the novel coronavirus disease (COVID-19), has posed a great public health threat to the global community as a pandemic. The origin of the virus has been linked to animals, through a yet-to-be-identified intermediate host. The disease is transmitted to humans mainly through inhalation or contact with infected droplets. The variable clinical presentation of COVID-19 includes fever, cough, sore throat, breathlessness, fatigue and malaise; however, cutaneous, ocular, neurological, and gastrointestinal manifestations have also been reported. There is an urgent need to strengthen One Health surveillance, intervention, and management strategies to understand the ecology of coronaviruses and to prevent epidemics in the future. Global attention toward the development of treatments, immunotherapies, vaccines, and control options to combat the COVID-19 pandemic has been on an increasing trend. Here, we review the current epidemiological status, public health concerns, and mitigation strategies for COVID-19.


Assuntos
Vacinas contra COVID-19/administração & dosagem , COVID-19/epidemiologia , COVID-19/prevenção & controle , Saúde Global/tendências , Saúde Pública/tendências , SARS-CoV-2 , Animais , Tosse/epidemiologia , Tosse/terapia , Surtos de Doenças/prevenção & controle , Febre/epidemiologia , Febre/terapia , Humanos , Pandemias/prevenção & controle , Saúde Pública/métodos , SARS-CoV-2/efeitos dos fármacos
20.
Probiotics Antimicrob Proteins ; 12(2): 705-715, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31485973

RESUMO

The present study examined the anti-biofilm efficacy of two short-chain antimicrobial peptides (AMPs), namely, indolicidin and cecropin A (1-7)-melittin (CAMA) against biofilm-forming multidrug-resistant enteroaggregative Escherichia coli (MDR-EAEC) isolates. The typical EAEC isolates re-validated by PCR and confirmed using HEp-2 cell adherence assay was subjected to antibiotic susceptibility testing to confirm its MDR status. The biofilm-forming ability of MDR-EAEC isolates was assessed by Congo red binding, microtitre plate assays and hydrophobicity index; broth microdilution technique was employed to determine minimum inhibitory concentrations (MICs) and minimum biofilm eradication concentrations (MBECs). The obtained MIC and MBEC values for both AMPs were evaluated alone and in combination against MDR-EAEC biofilms using crystal violet (CV) staining and confocal microscopy-based live/dead cell quantification methods. All the three MDR-EAEC strains revealed weak to strong biofilm-forming ability and were found to be electron-donating and weakly electron-accepting (hydrophobicity index). Also, highly significant (P < 0.001) time-dependent hydrodynamic growth of the three MDR-EAEC strains was observed at 48 h of incubation in Dulbecco's modified Eagle's medium (DMEM) containing 0.45% D-glucose. AMPs and their combination were able to inhibit the initial biofilm formation at 24 h and 48 h as evidenced by CV staining and confocal quantification. Further, the application of AMPs (individually and combination) against the preformed MDR-EAEC biofilms resulted in highly significant eradication (P < 0.001) at 24 h post treatment. However, significant differences were not observed between AMP treatments (individually or in combination). The AMPs seem to be an effective candidates for further investigations such as safety, stability and appropriate biofilm-forming MDR-EAEC animal models.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Biofilmes/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos
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