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1.
PLoS Negl Trop Dis ; 14(2): e0008036, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32106221

RESUMO

BACKGROUND: Multi-drug resistant typhoid fever remains an enormous public health threat in low and middle-income countries. However, we still lack a detailed understanding of the epidemiology and genomics of S. Typhi in many regions. Here we have undertaken a detailed genomic analysis of typhoid in urban Dhaka, Bangladesh to unravel the population structure and antimicrobial resistance patterns in S. Typhi isolated between 2004-2016. PRINCIPAL FINDINGS: Whole genome sequencing of 202 S. Typhi isolates obtained from three study locations in urban Dhaka revealed a diverse range of S. Typhi genotypes and AMR profiles. The bacterial population within Dhaka were relatively homogenous with little stratification between different healthcare facilities or age groups. We also observed evidence of exchange of Bangladeshi genotypes with neighboring South Asian countries (India, Pakistan and Nepal) suggesting these are circulating throughout the region. This analysis revealed a decline in H58 (genotype 4.3.1) isolates from 2011 onwards, coinciding with a rise in a diverse range of non-H58 genotypes and a simultaneous rise in isolates with reduced susceptibility to fluoroquinolones, potentially reflecting a change in treatment practices. We identified a novel S. Typhi genotype, subclade 3.3.2 (previously defined only to clade level, 3.3), which formed two localized clusters (3.3.2.Bd1 and 3.3.2.Bd2) associated with different mutations in the Quinolone Resistance Determining Region (QRDR) of gene gyrA. SIGNIFICANCE: Our analysis of S. Typhi isolates from urban Dhaka, Bangladesh isolated over a twelve year period identified a diverse range of AMR profiles and genotypes. The observed increase in non-H58 genotypes associated with reduced fluoroquinolone susceptibility may reflect a change in treatment practice in this region and highlights the importance of continued molecular surveillance to monitor the ongoing evolution of AMR in Dhaka. We have defined new genotypes and lineages of Bangladeshi S. Typhi which will facilitate the identification of these emerging AMR clones in future surveillance efforts.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Infecções por Salmonella/epidemiologia , Infecções por Salmonella/microbiologia , Salmonella typhi/efeitos dos fármacos , Bangladesh/epidemiologia , DNA Bacteriano/genética , Genoma Bacteriano , Genótipo , Humanos , Internacionalidade , Polimorfismo de Nucleotídeo Único , Estudos Retrospectivos , Infecções por Salmonella/transmissão , Salmonella typhi/genética , Salmonella typhi/isolamento & purificação , Fatores de Tempo , Viagem , População Urbana
2.
PLoS One ; 15(1): e0220484, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31990938

RESUMO

The growing occurrence of multidrug-resistant (MDR) Salmonella enterica in poultry has been reported with public health concern worldwide. We reported, recently, the occurrence of Escherichia coli and Salmonella enterica serovars carrying clinically relevant resistance genes in dairy cattle farms in the Wakiso District, Uganda, highlighting an urgent need to monitor food-producing animal environments. Here, we present the prevalence, antimicrobial resistance, and sequence type of 51 Salmonella isolates recovered from 379 environmental samples from chicken farms in Uganda. Among the Salmonella isolates, 32/51 (62.7%) were resistant to at least one antimicrobial, and 10/51 (19.6%) displayed multiple drug resistance. Through PCR, five replicon plasmids were identified among chicken Salmonella isolates including IncFIIS 17/51 (33.3%), IncI1α 12/51 (23.5%), IncP 8/51 (15.7%), IncX1 8/51 (15.7%), and IncX2 1/51 (2.0%). In addition, we identified two additional replicons through WGS (Whole Genome Sequencing; ColpVC and IncFIB). A significant seasonal difference between chicken sampling periods was observed (p = 0.0017). We conclude that MDR Salmonella highlights the risks posed to animals and humans. Implementing a robust, integrated surveillance system will aid in monitoring MDR zoonotic threats.


Assuntos
Farmacorresistência Bacteriana Múltipla/genética , Genes Bacterianos , Plasmídeos/metabolismo , Doenças das Aves Domésticas/epidemiologia , Infecções por Salmonella/epidemiologia , Salmonella enterica/genética , Animais , Antibacterianos/classificação , Antibacterianos/farmacologia , Galinhas/microbiologia , Fazendas , Humanos , Vigilância Imunológica , Plasmídeos/química , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/transmissão , Prevalência , Replicon , Infecções por Salmonella/microbiologia , Infecções por Salmonella/transmissão , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/isolamento & purificação , Estações do Ano , Uganda/epidemiologia , Sequenciamento Completo do Genoma
4.
Infect Immun ; 87(9)2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31262982

RESUMO

In recent years nontyphoidal Salmonella has emerged as one of the pathogens most frequently isolated from the bloodstream in humans. Only a small group of Salmonella serovars cause this systemic infection, known as invasive nontyphoidal salmonellosis. Here, we present a focused minireview on Salmonella enterica serovar Panama, a serovar responsible for invasive salmonellosis worldwide. S Panama has been linked with infection of extraintestinal sites in humans, causing septicemia, meningitis, and osteomyelitis. The clinical picture is often complicated by antimicrobial resistance and has been associated with a large repertoire of transmission vehicles, including human feces and breast milk. Nonhuman sources of S Panama involve reptiles and environmental reservoirs, as well as food animals, such as pigs. The tendency of S Panama to cause invasive disease may be linked to certain serovar-specific genetic factors.


Assuntos
Infecções por Salmonella/microbiologia , Salmonella enterica/patogenicidade , Farmacorresistência Bacteriana Múltipla , Saúde Global , Humanos , Infecções por Salmonella/transmissão , Salmonella enterica/genética , Virulência
5.
Zoonoses Public Health ; 66(6): 562-578, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31179637

RESUMO

Livestock meat and offal contribute significantly to human nutrition as sources of high-quality protein and micronutrients. Livestock products are increasingly in demand, particularly in low- and middle-income settings where economies are growing and meat is increasingly seen as an affordable and desirable food item. Demand is also driving intensification of livestock keeping and processing. An unintended consequence of intensification is increased exposure to zoonotic agents, and a contemporary emerging problem is infection with Campylobacter and Salmonella spp. from livestock (avian and mammalian), which can lead to disease, malabsorption and undernutrition through acute and chronic diarrhoea. This can occur at the farm, in households or through the food chain. Direct infection occurs when handling livestock and through bacteria shed into the environment, on food preparation surfaces or around the house and surroundings. This manuscript critically reviews Campylobacter and Salmonella infections in animals, examines the factors affecting colonization and faecal shedding of bacteria of these two genera as well as risk factors for human acquisition of the infection from infected animals or environment and analyses priority areas for preventive actions with a focus on resource-poor settings.


Assuntos
Derrame de Bactérias , Infecções por Campylobacter/veterinária , Campylobacter/isolamento & purificação , Infecções por Salmonella/microbiologia , Salmonella/isolamento & purificação , Zoonoses , Animais , Infecções por Campylobacter/microbiologia , Humanos , Infecções por Salmonella/transmissão
6.
PLoS Genet ; 15(6): e1008233, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31233504

RESUMO

Pathogenic Salmonella strains that cause gastroenteritis are able to colonize and replicate within the intestines of multiple host species. In general, these strains have retained an ability to form the rdar morphotype, a resistant biofilm physiology hypothesized to be important for Salmonella transmission. In contrast, Salmonella strains that are host-adapted or even host-restricted like Salmonella enterica serovar Typhi, tend to cause systemic infections and have lost the ability to form the rdar morphotype. Here, we investigated the rdar morphotype and CsgD-regulated biofilm formation in two non-typhoidal Salmonella (NTS) strains that caused invasive disease in Malawian children, S. Typhimurium D23580 and S. Enteritidis D7795, and compared them to a panel of NTS strains associated with gastroenteritis, as well as S. Typhi strains. Sequence comparisons combined with luciferase reporter technology identified key SNPs in the promoter region of csgD that either shut off biofilm formation completely (D7795) or reduced transcription of this key biofilm regulator (D23580). Phylogenetic analysis showed that these SNPs are conserved throughout the African clades of invasive isolates, dating as far back as 80 years ago. S. Typhi isolates were negative for the rdar morphotype due to truncation of eight amino acids from the C-terminus of CsgD. We present new evidence in support of parallel evolution between lineages of nontyphoidal Salmonella associated with invasive disease in Africa and the archetypal host-restricted invasive serovar; S. Typhi. We hypothesize that the African invasive isolates are becoming human-adapted and 'niche specialized' with less reliance on environmental survival, as compared to gastroenteritis-causing isolates.


Assuntos
Evolução Biológica , Gastroenterite/genética , Infecções por Salmonella/genética , Salmonella typhimurium/genética , África/epidemiologia , Biofilmes/crescimento & desenvolvimento , Criança , Gastroenterite/epidemiologia , Gastroenterite/microbiologia , Humanos , Filogenia , Polimorfismo de Nucleotídeo Único/genética , Infecções por Salmonella/microbiologia , Infecções por Salmonella/transmissão , Salmonella typhimurium/patogenicidade , Transativadores/genética
7.
Int J Food Microbiol ; 298: 1-10, 2019 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-30889473

RESUMO

Fresh betel leaves (Piper betle L.), imported into the UK are a traditional ready-to-eat food consumed by Asian populations. We report here the consolidation of routinely collected data to model the public health risks from consumption of this food. Amongst 2110 samples collected at Border Inspection, wholesale, catering or retail, Salmonella was detected in 488 (23%) of samples tested between 2011 and 2017 and was the most commonly Salmonella-contaminated ready-to-eat food examined by Public Health England during this period. Using data from multiple samples (usually 5) tested per consignment sampled at Border Inspection, contamination levels were calculated by most probable number: seasonal, temporal and country specific differences were detected. Quantitative contamination data was used to estimate the levels present at retail, and a ß-Poisson dose response model the probability of illness was calculated. Using data for products imported from India, the probability of acquiring infection following a single exposure (comprising of a single leaf) was estimated to be between 0.00003 (January-March) and 0.0001 (July-September). Using British Asian population data for individuals over 30 years of age in England in 2011, two estimates of consumption were modelled as 2.1 and 12.8 million servings per annum. Results from the model estimated 160 cases (range 102 to 242) and 960 cases (range 612 to 1456) per year in England for the two consumption estimates and equated to 34 (range 22 to 51) and 204 (range 130 to 310) salmonellosis cases per year reported to national surveillance. Salmonella from 475 of the contaminated samples were further characterised which showed a heterogeneous population structure with 46 S. enterica subsp. Enterica serovars, together with S. enterica subs diarizonae and salamae identified. Isolates from individual consignments were diverse and close genetic relationships between independent isolates were very rare except from within an individual consignment. There were no outbreaks detected as associated with betel leaf consumption. However analysis by whole genome sequencing of the 2014-17 data identified two cases where the clinical isolate had <5 single nucleotide polymorphism differences to isolates from betel leaves which is indicative of a likely epidemiological link and common source of contamination. Due to the diversity of the Salmonella contaminating this product, associations between salmonellosis cases and betel leaf consumption will appear sporadic and unlikely to be detected by current surveillance strategies based on outbreak detection.


Assuntos
Microbiologia de Alimentos , Modelos Estatísticos , Piper betle/microbiologia , Folhas de Planta/microbiologia , Saúde Pública/estatística & dados numéricos , Salmonella/fisiologia , Adulto , Inglaterra/epidemiologia , Humanos , Intoxicação Alimentar por Salmonella/prevenção & controle , Infecções por Salmonella/epidemiologia , Infecções por Salmonella/prevenção & controle , Infecções por Salmonella/transmissão
8.
Math Biosci Eng ; 16(2): 667-700, 2019 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-30861661

RESUMO

Sanitation and awareness programs play a fundamental role and are much effective public health interventions to control the spread of infectious diseases. In this paper, a nonlinear mathematical model for the control of infectious diseases, such as typhoid fever is proposed and analyzed by considering budget required for sanitation and awareness programs as a dynamic variable. It is assumed that the budget allocation regarding the protection against the disease to warn people and for sanitation increases logistically and its per-capita growth rate increases with the increase in number of infected individuals. In the model formulation, it is assumed that the susceptible individuals contract infection through the direct contact with infected individuals as well as indirectly through bacteria shed in the environment. It is further assumed that a fraction of budget is used to warn people via propagating awareness whereas the remaining part is used for sanitation to reduce the density of bacteria. The condition when budget should spend on sanitation/awareness to reduce the number of infected individuals is obtained. Model analysis reveals that the sanitation and awareness programs have capability to reduce the epidemic threshold and thus control the spread of infection. However, delay in providing funds destabilizes the system and may cause stability switches through Hopf-bifurcation. Numerical simulations are also carried out to support analytical findings.


Assuntos
Controle de Doenças Transmissíveis/métodos , Doenças Transmissíveis/transmissão , Infectologia/métodos , Infecções por Salmonella/transmissão , Saneamento , Algoritmos , Países em Desenvolvimento , Epidemias , Humanos , Índia , Dinâmica não Linear , Saúde Pública , Salmonella typhi , Microbiologia da Água , Poluentes da Água
9.
Zoonoses Public Health ; 66(4): 370-376, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30821071

RESUMO

In the United States, multistate Salmonella outbreaks are most commonly linked to a food source; however, contact with live animals can also result in outbreaks of human illness. To characterize Salmonella outbreaks linked to animal contact and examine differences compared to foodborne outbreaks, we analysed data reported to the Centers for Disease Control and Prevention through the National Outbreak Reporting System (NORS) from 2009 to 2014 with a primary mode of transmission listed as "animal contact" or "food." Four hundred and eighty-four outbreaks with animal contact or foodborne transmission were reported through NORS; of these outbreaks, 99 (20.5%) resulted from Salmonella transmission through animal contact and 385 (79.5%) resulted from foodborne transmission, which resulted in 3,604 (19.8%) and 13,568 (80.2%) illnesses, respectively. A higher proportion of illnesses among children aged <1 year and children aged 1-4 years were linked to animal contact outbreaks compared to foodborne outbreaks (15.2% vs. 1.4%, p < 0.01 and 24.5% vs. 5.6%, p < 0.01, respectively). Illnesses resulting in hospitalizations (OR: 1.81, 95% CI: 1.62, 2.02) were more likely to be associated with animal contact compared to food. Animal contact outbreaks reported to NORS were more likely to be multistate compared to foodborne outbreaks (OR: 5.43, 95% CI: 3.37, 8.76) and had a longer median duration (99.0 days vs. 9.0 days, p < 0.01). Characterizing the differences between outbreaks of illness linked to animal contact and outbreaks linked to food provides useful information to investigators to improve public health response.


Assuntos
Surtos de Doenças/estatística & dados numéricos , Intoxicação Alimentar por Salmonella/epidemiologia , Infecções por Salmonella/epidemiologia , Infecções por Salmonella/transmissão , Salmonella enterica/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Feminino , Hospitalização , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Vigilância em Saúde Pública , Estados Unidos/epidemiologia , Adulto Jovem
10.
J Forensic Sci ; 64(5): 1304-1311, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30801721

RESUMO

Most emerging or re-emerging infections are vector-borne or zoonotic and can be disseminated worldwide by infected humans or animals. They are a major public health problem and cause a great impact on economy. Zoonotic outbreaks began to be characterized in the 90s, after the creation of Europol and the FBI. Such investigations are carried by forensic pathologists and other specialists to determine whether an outbreak is natural or deliberate. This review will discuss ten zoonotic outbreaks nonrelated to wars focusing on forensic management. In conclusion, some points should be highlighted in the management of a zoonotic outbreak: (i) its diagnosis and detection by forensic pathologists and the coordination of efforts between other specialists are key factors; (ii) communication guidelines and an efficient healthcare system are crucial for any emergency response; (iii) biosafety of all specialists involved must be guaranteed.


Assuntos
Surtos de Doenças , Zoonoses/epidemiologia , Animais , Antraz/epidemiologia , Antraz/transmissão , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/transmissão , Febre Aftosa/epidemiologia , Febre Aftosa/transmissão , Medicina Legal , Gastroenterite/epidemiologia , Gastroenterite/microbiologia , Síndrome Pulmonar por Hantavirus/epidemiologia , Síndrome Pulmonar por Hantavirus/transmissão , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/transmissão , História do Século XX , História do Século XXI , Humanos , Infecções por Salmonella/epidemiologia , Infecções por Salmonella/transmissão , Escherichia coli Shiga Toxigênica , Tularemia/epidemiologia , Tularemia/transmissão , Febre do Nilo Ocidental/epidemiologia , Febre do Nilo Ocidental/transmissão
11.
BMC Genomics ; 20(1): 20, 2019 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-30621582

RESUMO

BACKGROUND: Salmonella enterica subspecies enterica is an animal and zoonotic pathogen of global importance. Cattle are a significant reservoir of human non-typhoidal salmonellosis and can suffer enteric and systemic disease owing to the ability of Salmonella to survive within the bovine lymphatic system and intestines. Contamination of food can occur due to the incorporation of contaminated peripheral lymph nodes or by direct contamination of carcasses with gut contents. It is essential to understand the mechanisms used by Salmonella to enter and persist within the bovine lymphatic system and how they differ from those required for intestinal colonization to minimize zoonotic infections. RESULTS: Transposon-directed insertion site sequencing (TraDIS) was applied to pools of mutants recovered from mesenteric lymph nodes (MLNs) draining the distal ileum of calves after oral inoculation with a library of 8550 random S. Typhimurium mini-Tn5Km2 mutants in pools of 475 mutants per calf. A total of 8315 mutants representing 2852 different genes were detected in MLNs and their in vivo fitness was calculated. Using the same improved algorithm for analysis of transposon-flanking sequences, the identity and phenotype of mutants recovered from the distal ileal mucosa of the same calves was also defined, enabling comparison with previously published data and of mutant phenotypes across the tissues. Phenotypes observed for the majority of mutants were highly significantly correlated in the two tissues. However, 32 genes were identified in which transposon insertions consistently resulted in differential fitness in the ileal wall and MLNs, suggesting niche-specific roles for these genes in pathogenesis. Defined null mutations affecting ptsN and spvC were confirmed to result in tissue-specific phenotypes in calves, thus validating the TraDIS dataset. CONCLUSIONS: This validation of the role of thousands of Salmonella genes and identification of genes with niche-specific roles in a key target species will inform the design of control strategies for bovine salmonellosis and zoonotic infections, for which efficacious and cross-protective vaccines are currently lacking.


Assuntos
Elementos de DNA Transponíveis/genética , Infecções por Salmonella/genética , Salmonella enterica/genética , Salmonella typhimurium/genética , Animais , Carbono-Oxigênio Liases/genética , Bovinos , Doenças dos Bovinos/genética , Doenças dos Bovinos/microbiologia , Reservatórios de Doenças/microbiologia , Humanos , Íleo/microbiologia , Intestinos/microbiologia , Linfonodos/microbiologia , Mutação , Infecções por Salmonella/microbiologia , Infecções por Salmonella/transmissão , Salmonella enterica/patogenicidade , Salmonella typhimurium/patogenicidade
13.
mBio ; 9(5)2018 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-30181247

RESUMO

Nontyphoidal Salmonella (NTS), particularly Salmonella enterica serovar Typhimurium, is among the leading etiologic agents of bacterial enterocolitis globally and a well-characterized cause of invasive disease (iNTS) in sub-Saharan Africa. In contrast, S Typhimurium is poorly defined in Southeast Asia, a known hot spot for zoonotic disease with a recently described burden of iNTS disease. Here, we aimed to add insight into the epidemiology and potential impact of zoonotic transfer and antimicrobial resistance (AMR) in S Typhimurium associated with iNTS and enterocolitis in Vietnam. We performed whole-genome sequencing and phylogenetic reconstruction on 85 human (enterocolitis, carriage, and iNTS) and 113 animal S Typhimurium isolates isolated in Vietnam. We found limited evidence for the zoonotic transmission of S Typhimurium. However, we describe a chain of events where a pandemic monophasic variant of S Typhimurium (serovar I:4,[5],12:i:- sequence type 34 [ST34]) has been introduced into Vietnam, reacquired a phase 2 flagellum, and acquired an IncHI2 multidrug-resistant plasmid. Notably, these novel biphasic ST34 S Typhimurium variants were significantly associated with iNTS in Vietnamese HIV-infected patients. Our study represents the first characterization of novel iNTS organisms isolated outside sub-Saharan Africa and outlines a new pathway for the emergence of alternative Salmonella variants into susceptible human populations.IMPORTANCESalmonella Typhimurium is a major diarrheal pathogen and associated with invasive nontyphoid Salmonella (iNTS) disease in vulnerable populations. We present the first characterization of iNTS organisms in Southeast Asia and describe a different evolutionary trajectory from that of organisms causing iNTS in sub-Saharan Africa. In Vietnam, the globally distributed monophasic variant of Salmonella Typhimurium, the serovar I:4,[5],12:i:- ST34 clone, has reacquired a phase 2 flagellum and gained a multidrug-resistant plasmid to become associated with iNTS disease in HIV-infected patients. We document distinct communities of S Typhimurium and I:4,[5],12:i:- in animals and humans in Vietnam, despite the greater mixing of these host populations here. These data highlight the importance of whole-genome sequencing surveillance in a One Health context in understanding the evolution and spread of resistant bacterial infections.


Assuntos
Farmacorresistência Bacteriana Múltipla , Salmonelose Animal/epidemiologia , Salmonelose Animal/microbiologia , Infecções por Salmonella/epidemiologia , Infecções por Salmonella/microbiologia , Salmonella typhimurium/classificação , Salmonella typhimurium/efeitos dos fármacos , Animais , Bacteriemia/epidemiologia , Bacteriemia/microbiologia , Portador Sadio/epidemiologia , Portador Sadio/microbiologia , Galinhas , Transmissão de Doença Infecciosa , Patos , Gastroenterite/epidemiologia , Gastroenterite/microbiologia , Variação Genética , Genótipo , Infecções por HIV/complicações , Humanos , Hospedeiro Imunocomprometido , Epidemiologia Molecular , Infecções por Salmonella/transmissão , Salmonelose Animal/transmissão , Salmonella typhimurium/genética , Salmonella typhimurium/isolamento & purificação , Suínos , Vietnã/epidemiologia , Sequenciamento Completo do Genoma , Zoonoses/epidemiologia , Zoonoses/microbiologia , Zoonoses/transmissão
14.
Adv Food Nutr Res ; 86: 137-179, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30077221

RESUMO

The number of human salmonellosis within the European Union tended to increase since 2013. One of the reasons might be Salmonella Enteritidis rising in laying hens flocks by around 17% in 2015 vs 2014 and by 57% in 2016 vs 2015. The most important sources of food-borne Salmonella outbreaks are still eggs and egg products as well as ready-to-eat foods having a long shelf life. Specific actions are suggested to restart decreasing the number of human salmonellosis: (1) revision of sampling schemes to solve pathogen under detection in both animals and foods; (2) integration of microbiological criteria with fit for purpose performance objectives and food safety objectives; and (3) improvement of epidemiological investigations of human, food, and animal isolates by using whole-genome sequencing in order to effectively track salmonellosis and verify which prevention measures are most effective.


Assuntos
Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Infecções por Salmonella/microbiologia , Infecções por Salmonella/transmissão , Salmonella/isolamento & purificação , Animais , Doenças Transmissíveis Emergentes , Humanos
15.
Microbiology ; 164(11): 1327-1344, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30136920

RESUMO

Global Salmonella infection, especially in developing countries, is a health and economic burden. The use of antibiotic drugs in treating the infection is proving less effective due to the alarming rise of antibiotic-resistant strains of Salmonella, the effects of antibiotics on normal gut microflora and antibiotic-associated diarrhoea, all of which bring a growing need for alternative treatments, including the use of probiotic micro-organisms. However, there are issues with probiotics, including their potential to be opportunistic pathogens and antibiotic-resistant carriers, and their antibiotic susceptibility if used as complementary therapy. Clinical trials, animal trials and in vitro investigations into the prophylactic and therapeutic efficacies of probiotics have demonstrated antagonistic properties against Salmonella and other enteropathogenic bacteria. Nonetheless, there is a need for further studies into the potential mechanisms, efficacy and mode of delivery of yeast probiotics in Salmonella infections. This review discusses Salmonella infections and treatment using antibiotics and probiotics.


Assuntos
Antibacterianos/uso terapêutico , Probióticos/uso terapêutico , Infecções por Salmonella/tratamento farmacológico , Infecções por Salmonella/prevenção & controle , Biofilmes/crescimento & desenvolvimento , Farmacorresistência Bacteriana Múltipla , Microbioma Gastrointestinal/efeitos dos fármacos , Humanos , Salmonella/efeitos dos fármacos , Salmonella/patogenicidade , Infecções por Salmonella/transmissão
16.
Zoonoses Public Health ; 65(7): 766-776, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29984468

RESUMO

Salmonella is one of the common causes of food-borne bacterial illnesses. The primary sources of human nontyphoidal Salmonella (NTS) infection are food animals. This study characterized temporally and spatially related Salmonella isolated during April 2013 to March 2014 from faeces of diarrhoeic human patients in Addis Ababa (n = 68) and food animals (n = 84) in Addis Ababa and surrounding districts (dairy cattle, n = 30; slaughtered cattle, n = 20; poultry, n = 26; swine n = 8). Isolates were serotyped, page typed and tested for antimicrobial susceptibility using Kirby-Bauer disc diffusion method, and genotyped by pulsed-field gel electrophoresis (PFGE). The dominant Salmonella serovars isolated from food animals were S. Saintpaul (38.1%), S. Typhimurium (17.9%) and S. Kentucky (9.5%), whereas in humans, S. Typhimurium (39.7%), S. Virchow (30.9%) and S. Kottbus (10.3%) were frequently isolated. Resistance to streptomycin, sulfisoxazole, tetracycline, ampicillin and cephalothin was higher in animal isolates than human isolates, and mean number of antimicrobials to which isolates were resistant was significantly higher in isolates from cattle and poultry compared to those from humans (p < 0.05). All S. Kentucky isolated from animals and humans were multidrug resistant (MDR) with shared resistance phenotype (AmpCfCipTeSuSNa). Although this study involved small sample size and was not able to show clear epidemiological linkage among isolates from various sources, genotyping by PFGE analysis demonstrated circulation of closely related genotypes of S. Virchow, S. Typhimurium and S. Kentucky among humans and food animals. Detection of related Salmonella isolates from humans and animals, the high MDR status of isolates from animals and close proximity of farms and human residential areas in the absence of appropriate biosecurity present major public health problem. Integrated surveillance of Salmonella serovars in humans and animals and implementation of appropriate hazard analysis and pathogen control strategies along critical points of the food chain from farm to table is recommended.


Assuntos
Salmonelose Animal/microbiologia , Infecções por Salmonella/microbiologia , Salmonella/classificação , Salmonella/isolamento & purificação , Animais , Diarreia/epidemiologia , Diarreia/microbiologia , Etiópia/epidemiologia , Microbiologia de Alimentos , Humanos , Gado , Salmonella/genética , Infecções por Salmonella/epidemiologia , Infecções por Salmonella/transmissão , Salmonelose Animal/epidemiologia
17.
PLoS One ; 13(7): e0201031, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30024964

RESUMO

The transmission of Salmonella enterica within a vertically integrated poultry operation was investigated longitudinally over an 18-month period (2013-2014). Thirty six percent of all samples collected (1503 of 4219) were positive for salmonellae with seven Salmonella enterica subsp. enterica serovars, and one Salmonella enterica subsp. salamae serovar detected. Both Salmonella enterica subsp. enterica serovars Infantis and Typhimurium were detected in all locations sampled. Salmonella Typhimurium was the most frequently detected serovar (63% of serotyped samples) with 8 phage types (PT) and 41 multiple-locus variable-number tandem-repeats analysis (MLVA) profiles identified. The most frequently identified phage types were PT135a and DT135. A total of 62 PT/MLVA combinations were observed. MLVA profiles 03-14-10-09-525 and 03-15-11-11-525 were the most frequently identified and 83% of the isolates shared at least one MLVA profile with an isolate from another phage type. The use of phage typing and MLVA profiling, on their own or in combination, were insufficient to understand the complexity of the epidemiological relationships between locations within this production system. Despite the high level of apparent diversity, cluster analysis was unable to differentiate the transmission pathways of all S. Typhimurium variants detected within the integrated enterprise. Using additional epidemiological information, the parent breeder rearing site was identified as the most likely point of introduction of two S. Typhimurium isolates into the production system with subsequent dissemination to the broiler flocks via the hatchery. This complexity is unable to be resolved in the absence of intensive sampling programs at all generations of the production system.


Assuntos
Tipagem de Bacteriófagos/métodos , Tipagem Molecular/métodos , Fenótipo , Aves Domésticas/microbiologia , Infecções por Salmonella/transmissão , Salmonella/classificação , Sorotipagem/métodos , Animais , Galinhas , Genótipo , Repetições Minissatélites , Salmonella/genética , Salmonella/isolamento & purificação , Infecções por Salmonella/microbiologia
19.
J Hosp Infect ; 100(4): e233-e238, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29614246

RESUMO

BACKGROUND: Repeated outbreaks of salmonellosis caused by Salmonella enterica serovar Infantis at a rehabilitation clinic in Germany were investigated microbiologically from August 2002 to August 2009. AIM: To identify the sources of transmission and characterize the S. enterica serovar Infantis isolates. METHODS: Associated with these outbreaks, isolates from 98 patients, two kitchen staff, five food samples, four swabs of kitchen facilities, three samples of chicken faeces and one sample of sewage water were evaluated by phage typing. All S. enterica serovar Infantis isolates investigated (N=113) were related to phage type (PT) 29. Additionally, 44 of the 113 isolates were selected at random for typing by XbaI macrorestriction and pulsed-field gel electrophoresis (PFGE). FINDINGS: Typing of the 44 isolates showed that the recurrent infections were caused by the single clone PT 29/XB27+44 (42/44, 95.5%). The most likely route of transmission was only identified in the last outbreak in 2009 within the present study. It was found to be cross-contamination in the kitchen facilities (emanating from a contaminated wooden panel), in combination with carriers among the kitchen staff. CONCLUSIONS: This study demonstrated important details of hospital-specific epidemiological processes, and alludes to a long-term reservoir of an epidemic clone of S. enterica serovar Infantis either in a backyard flock of poultry or in an inanimate kitchen reservoir.


Assuntos
Infecção Hospitalar/epidemiologia , Surtos de Doenças , Infecções por Salmonella/epidemiologia , Salmonella enterica/isolamento & purificação , Infecção Hospitalar/microbiologia , Infecção Hospitalar/transmissão , Transmissão de Doença Infecciosa , Eletroforese em Gel de Campo Pulsado , Microbiologia Ambiental , Fezes/microbiologia , Microbiologia de Alimentos , Genótipo , Alemanha/epidemiologia , Humanos , Tipagem Molecular , Recidiva , Centros de Reabilitação , Infecções por Salmonella/microbiologia , Infecções por Salmonella/transmissão , Salmonella enterica/classificação , Salmonella enterica/genética , Sorogrupo , Esgotos/microbiologia
20.
Artigo em Inglês | MEDLINE | ID: mdl-29531146

RESUMO

Provision of supplementary food for wild birds at garden feeding stations is a common, large-scale and year-round practice in multiple countries including Great Britain (GB). While these additional dietary resources can benefit wildlife, there is a concomitant risk of disease transmission, particularly when birds repeatedly congregate in the same place at high densities and through interactions of species that would not normally associate in close proximity. Citizen science schemes recording garden birds are popular and can integrate disease surveillance with population monitoring, offering a unique opportunity to explore inter-relationships between supplementary feeding, disease epidemiology and population dynamics. Here, we present findings from a national surveillance programme in GB and note the dynamism of endemic and emerging diseases over a 25-year period, focusing on protozoal (finch trichomonosis), viral (Paridae pox) and bacterial (passerine salmonellosis) diseases with contrasting modes of transmission. We also examine the occurrence of mycotoxin contamination of food residues in bird feeders, which present both a direct and indirect (though immunosuppression) risk to wild bird health. Our results inform evidence-based mitigation strategies to minimize anthropogenically mediated health hazards, while maintaining the benefits of providing supplementary food for wild birds.This article is part of the theme issue 'Anthropogenic resource subsidies and host-parasite dynamics in wildlife'.


Assuntos
Doenças das Aves/epidemiologia , Passeriformes/imunologia , Infecções por Poxviridae/veterinária , Infecções por Salmonella/epidemiologia , Tricomoníase/veterinária , Ração Animal/provisão & distribução , Animais , Doenças das Aves/imunologia , Doenças das Aves/transmissão , Monitoramento Epidemiológico , Humanos , Imunidade Inata , Micotoxinas/análise , Passeriformes/microbiologia , Passeriformes/parasitologia , Passeriformes/virologia , Dinâmica Populacional/estatística & dados numéricos , Infecções por Poxviridae/epidemiologia , Infecções por Poxviridae/imunologia , Infecções por Poxviridae/transmissão , Fatores de Risco , Infecções por Salmonella/imunologia , Infecções por Salmonella/transmissão , Tricomoníase/epidemiologia , Tricomoníase/imunologia , Tricomoníase/transmissão , Reino Unido/epidemiologia
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