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1.
Emerg Infect Dis ; 24(3): 562-565, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29460759

RESUMEN

Human infections with Salmonella enterica serovar Napoli are uncommon in Europe. However, these infections represented 5.9% of salmonellosis cases in Italy during 2014-2015. The source of infection is unknown. We analyzed surveillance data and compared strain genetic similarities and found that contaminated vegetables and surface water are probable sources of human infection.


Asunto(s)
Enfermedades Transmisibles Emergentes/epidemiología , Enfermedades Transmisibles Emergentes/microbiología , Infecciones por Salmonella/epidemiología , Infecciones por Salmonella/microbiología , Salmonella enterica/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Enfermedades Transmisibles Emergentes/historia , Femenino , Variación Genética , Historia del Siglo XXI , Humanos , Lactante , Italia/epidemiología , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Filogenia , Infecciones por Salmonella/historia , Salmonella enterica/clasificación , Adulto Joven
2.
Euro Surveill ; 21(15)2016 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-27105170

RESUMEN

Monophasic variant of Salmonella enterica subspecies enterica serovar Typhimurium (monophasic S. Typhimurium), with antigenic structure 1,4,[5],12:i:-, appears to be of increasing importance in Europe. In Italy, monophasic S. Typhimurium represented the third most frequent Salmonella serovar isolated from human cases between 2004 and 2008. From June 2013 to October 2014, a total of 206 human cases of salmonellosis were identified in Abruzzo region (Central Italy). Obtained clinical isolates characterised showed S. Typhimurium 1,4,[5],12:i:- with sole resistance to nalidixic acid, which had never been observed in Italy in monophasic S. Typhimurium, neither in humans nor in animals or foods. Epidemiological, microbiological and environmental investigations were conducted to try to identify the outbreak source. Cases were interviewed using a standardised questionnaire and microbiological tests were performed on human as well as environmental samples, including samples from fruit and vegetables, pigs, and surface water. Investigation results did not identify the final vehicle of human infection, although a link between the human cases and the contamination of irrigation water channels was suggested.


Asunto(s)
Brotes de Enfermedades/estadística & datos numéricos , Vigilancia de la Población , Salmonella typhi/clasificación , Salmonella typhi/aislamiento & purificación , Fiebre Tifoidea/epidemiología , Fiebre Tifoidea/microbiología , Adolescente , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Trazado de Contacto , Femenino , Humanos , Incidencia , Lactante , Recién Nacido , Italia/epidemiología , Masculino , Persona de Mediana Edad , Distribución por Sexo , Especificidad de la Especie , Adulto Joven
3.
Foodborne Pathog Dis ; 13(9): 490-4, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27455195

RESUMEN

Campylobacter spp. is the most common gastrointestinal pathogen worldwide with a very low reported incidence in Italy. In November of 2013, local and national public health authorities investigated an outbreak caused by Campylobacter jejuni among children in a kindergarten in Northern Italy. A case was defined as a child who had diarrhea with a laboratory-confirmed diagnosis of C. jejuni between 11 and 30 November. Stool samples from the kindergarten kitchen staff and environmental samples from the kitchen were examined for enteric pathogens. As food leftovers were not available, the menu logbook of the refectory was reviewed to identify a possible source of the outbreak. C. jejuni strains were tested for antimicrobial susceptibility and subtyped by pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). We identified 20 cases among 247 schoolchildren (attack rate = 8%), all who reported having lunch in the kindergarten. The stools from the kitchen staff as well as the environmental samples were negative for enteric pathogens. The identified outbreak strains (n = 5) were sensitive to all of the antimicrobials tested; the first four strains showed an identical PFGE profile, whereas the fifth strain showed a PFGE pattern similarity of 89%. Using MLST, all five strains were assigned to a single sequence type (ST), ST451 (clonal complex, CC21); this was the first identification of ST and the third reported outbreak of C. jejuni in Italy. Molecular typing confirmed that most of the cases belonged to a clonal cluster supporting the hypothesis of a common source; however, the source was not identified. Due to a delayed start of the investigation, it was not possible to perform any microbiological evaluation of the food consumed.


Asunto(s)
Infecciones por Campylobacter/epidemiología , Campylobacter jejuni/aislamiento & purificación , Brotes de Enfermedades , Técnicas de Tipificación Bacteriana , Campylobacter jejuni/clasificación , Campylobacter jejuni/genética , Preescolar , Electroforesis en Gel de Campo Pulsado , Heces/microbiología , Femenino , Genotipo , Humanos , Italia/epidemiología , Masculino , Epidemiología Molecular , Tipificación de Secuencias Multilocus , Instituciones Académicas
4.
Foodborne Pathog Dis ; 11(2): 138-44, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24328499

RESUMEN

Salmonella enterica subsp. enterica serovar 4,[5],12:i:- DT193 is recognized as an emerging monophasic variant of Salmonella Typhimurium in many European countries. Resistance to ampicillin, streptomycin, sulphonamides, and tetracycline (R-type ASSuT) is described as one of the most common profiles of resistance within this clone. Recently, strains presenting such features were isolated from two unrelated outbreaks in Italy. Strains were characterized by pulsed-field gel electrophoresis (PFGE), performed with XbaI, BlnI, and SpeI, and multiple-locus variable-number tandem repeat analysis (MLVA). XbaI-PFGE showed strains related to the two outbreaks as indistinguishable. Conversely, both BlnI-PFGE and MLVA characterized the strains related the two outbreaks as different. XbaI-PFGE identified two profiles, differing by one band, within strains isolated from one of the two outbreaks. Also BlnI-PFGE and MLVA generated different profiles among the strains related to that outbreak. Combining the PFGE profiles obtained by XbaI and BlnI and comparing them with the MLVA profiles, the two methods grouped the same isolates based on identity. Moreover, genomic deletions of the genes included in the operon fljAB, the flanking iroB gene, and the closely located STM2757 gene were investigated. For all strains, the same profile of deletion characterized by the absence of fljA, fljB, and hin genes and the presence of STM2757 and iroB genes was identified. This profile of deletion represents a mixture between two profiles of Salmonella 4,[5],12:i:- described as the "Spanish" and the "U.S." clones. This study demonstrated that although strains of Salmonella 4,[5],12:i:- DT193 ASSuT are highly clonal, minor differences between strains may be seen during the same outbreak by using in parallel PFGE with different restriction enzymes, MLVA, and the analysis of molecular markers related to the operon fljAB. The combination of these different molecular approaches was essential to clarify the epidemiological relationship among the strains.


Asunto(s)
Brotes de Enfermedades , Enfermedades Transmitidas por los Alimentos/epidemiología , Productos de la Carne/microbiología , Salmonella enterica/genética , Salmonella enterica/aislamiento & purificación , Animales , Proteínas Bacterianas/genética , Pollos , Mapeo Cromosómico , ADN Bacteriano/genética , Electroforesis en Gel de Campo Pulsado , Heces/microbiología , Flagelina/genética , Contaminación de Alimentos/análisis , Microbiología de Alimentos , Enfermedades Transmitidas por los Alimentos/microbiología , Humanos , Italia/epidemiología , Proteínas Represoras/genética , Salmonella enterica/clasificación , Salmonella typhimurium/genética , Salmonella typhimurium/aislamiento & purificación , Porcinos
5.
Antibiotics (Basel) ; 12(9)2023 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-37760674

RESUMEN

In this study, we describe a Salmonella enterica serovar (S.) Rissen strain with a reduced susceptibility to meropenem, isolated from a urinary infection in an 89-year-old woman in 2018 during activity surveillance in Italy (Enter-Net Italia). The genomic characteristics, pathogenicity, and antimicrobial resistance mechanisms were investigated via a genomic approach. Antimicrobial susceptibility testing revealed a "susceptible, increased exposure" phenotype to meropenem in the S. Rissen strain (4_29_19). Whole-genome sequencing (WGS) was performed using both the NovaSeq 6000 S4 PE150 XP platform (Illumina, San Diego, CA, USA) and MinION (Oxford Nanopore). The S. Rissen 4_29_19 strain harboured two plasmids: a pKpQIL-like plasmid carrying the blaKPC-3 resistance gene in a Tn4401a transposon (pKPC_4_29_19), and a ColE-like plasmid (p4_4_29_19) without resistance genes, highly prevalent among Enterobacterales. Comparative analysis revealed that the pKPC_4_29_19 plasmid was highly related to the pKpQIL reference plasmid (GU595196), with 57% coverage and 99.96% identity, but lacking a region of about 30 kb, involving the FIIK2 replicon region and the entire transfer locus, causing the loss of its ability to conjugate. To our knowledge, this is the first time that a pKpQIL-like plasmid, carrying blaKPC-3, highly diffused in Klebsiella pneumoniae strains, has been identified in a Salmonella strain in our country. The acquisition of blaKPC genes by Salmonella spp. is extremely rare, and is reported only sporadically. In zoonotic bacteria isolated from humans, the presence of a carbapenem resistance gene carried by mobile genetic elements, usually described in healthcare-associated infection bacteria, represents an important concern for public health.

6.
Microorganisms ; 11(10)2023 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-37894225

RESUMEN

The monophasic variant of S. Typhimurium 4,[5],12:i:- (MVST) is the third most commonly reported Salmonella serovar involved in human infections (8.8%) in the EU and ranks after S. Enteritidis (54.6%) and S. Typhimurium (11.4%). In Italy, in contrast, the MVST has achieved peculiar epidemiological and ecological success which has allowed it to be, since 2011, the serovar most frequently isolated from humans. In the summer of 2022, a foodborne outbreak of the MVST involving 63 people occurred in the Marche Region (Central Italy). A common food exposure source among some human cases was a roasted, ready-to-eat (RTE) pork product, porchetta, which is a typical product of Central Italy. This paper describes the results of investigations conducted to clarify this outbreak. The porchetta was produced by a local manufacturing plant and distributed to at least two local retail stores, one of which was the retail outlet for the manufacturing plant. The MVST was isolated from surface samples collected at the porchetta manufacturing plant and at both local retail stores via bacterial analysis, and the porchetta sampled at one store contained the MVST. These data confirm this type of RTE pork product can be a source of Salmonella infection in humans.

7.
Trop Med Infect Dis ; 8(5)2023 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-37235314

RESUMEN

Despite the number of cholera outbreaks reported worldwide, only a few cases are recorded among returning European travellers. We describe the case of a 41-year-old male, returning to Italy after a stay in Bangladesh, his origin country, who presented with watery diarrhoea. Vibrio cholerae and norovirus were detected in the patient's stools via multiplex PCR methods. Direct microscopy, Gram staining, culture and antibiotic susceptibility tests were performed. The isolates were tested using end-point PCR for the detection of potentially enteropathogenic V. cholera. Serotype and cholera toxins identification were carried out. Whole genome sequencing and bioinformatics analysis were performed, and antimicrobial resistance genes identified. A phylogenetic tree with the most similar genomes of databases previously described was built. Sample of the food brought back by the patient were also collected and analysed. The patient was diagnosed with V. cholerae O1, serotype Inaba, norovirus and SARS-CoV-2 concomitant infection. The isolated V. cholerae strain was found to belong to ST69, encoding for cholera toxin, ctxB7 type and was phylogenetically related to the 2018 outbreak in Dhaka, Bangladesh. Adopting a multidisciplinary approach in a cholera non-endemic country ensured rapid and accurate diagnosis, timely clinical management, and epidemiological investigation at national and international level.

8.
J Antimicrob Chemother ; 67(1): 111-4, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21990047

RESUMEN

OBJECTIVES: The aim of this study was to sequence the chromosomal region conferring resistance to ampicillin, streptomycin, sulphonamides and tetracycline (R-type ASSuT) in a Salmonella Typhimurium (STM) monophasic strain (4,[5],12:i:-) belonging to the PFGE profile STYMXB.0079. The presence of this resistance region and the analysis of its genetic environment was investigated in a selection of strains. METHODS: A Sau3A1 genomic library was used to determine the nucleotide sequence of the genomic resistance region. PCRs were performed on 10 epidemiologically unrelated Salmonella strains, both STM and monophasic STM, with R-type ASSuT and PFGE profile STYMXB.0079, in order to investigate the presence of the resistance genes, the left and right junctions and the internal regions of the resistance region, as well as the genetic environment. RESULTS: The genomic resistance region consisted of two regions, resistance region 1 (RR1), conferring resistance to ampicillin, streptomycin and sulphonamides, and resistance region 2 (RR2), conferring tetracycline resistance. These resistance regions were both surrounded by IS26 elements and sequence comparative analysis showed 99% sequence identity with a region of plasmid pO111_1 from an Escherichia coli strain. All 10 strains were positive for the four resistance genes, the left and right junctions and the internal regions of RR1 and RR2. Concerning the genetic environment, all the strains lacked the STM1053-1997 and STM2694 genes, while only monophasic STM strains showed deletion of the fljA-fljB operon. CONCLUSIONS: This study describes two resistance regions localized on the bacterial chromosome of a clonal lineage of STM and monophasic STM that are widespread in Italy.


Asunto(s)
Antibacterianos/farmacología , Secuencia de Bases , Cromosomas Bacterianos , ADN Bacteriano/genética , Farmacorresistencia Bacteriana Múltiple , Salmonella typhimurium/genética , ADN Bacteriano/química , Electroforesis en Gel de Campo Pulsado , Escherichia coli/genética , Genotipo , Humanos , Italia , Datos de Secuencia Molecular , Tipificación Molecular , Plásmidos , Reacción en Cadena de la Polimerasa , Infecciones por Salmonella/microbiología , Salmonella typhimurium/clasificación , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/aislamiento & purificación , Análisis de Secuencia de ADN , Homología de Secuencia
9.
Antibiotics (Basel) ; 11(1)2022 01 13.
Artículo en Inglés | MEDLINE | ID: mdl-35052978

RESUMEN

BACKGROUND: A collection of human-epidemiologically unrelated S. enterica strains collected over a 3-year period (2016 to 2018) in Italy by the national surveillance Enter-Net Italia was analysed. METHODS: Antimicrobial susceptibility tests, including the determination of minimal inhibitory concentrations (MICs) for colistin, were performed. Colistin resistant strains were analysed by PCR to detect mobile colistin resistance (mcr) genes. In mcr-negative S. enterica serovar Enteritidis strains, chromosomal mutations potentially involved in colistin resistance were identified by a genomic approach. RESULTS: The prevalence of colistin-resistant S. enterica strains was 7.7%, the majority (87.5%) were S. Enteritidis. mcr genes were identified only in one strain, a S. Typhimurium monophasic variant, positive for both mcr-1.1 and mcr-5.1 genes in an IncHI2 ST4 plasmid. Several chromosomal mutations were identified in the colistin-resistant mcr-negative S. Enteritidis strains in proteins involved in lipopolysaccharide and outer membrane synthesis and modification (RfbN, LolB, ZraR) and in a component of a multidrug efflux pump (MdsC). These mutated proteins were defined as possible candidates for colistin resistance in mcr-negative S. Enteritidis of our collection. CONCLUSIONS: The colistin national surveillance in Salmonella spp. in humans, implemented with genomic-based surveillance, permitted to monitor colistin resistance, determining the prevalence of mcr determinants and the study of new candidate mechanisms for colistin resistance.

10.
Foodborne Pathog Dis ; 8(9): 997-1003, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21561382

RESUMEN

Salmonella enterica serovar Napoli is an emerging serovar in Italy, France, and Switzerland, but little is known about its pathogenicity to humans. A collection of 112 strains of Salmonella Napoli isolated in Italy from human cases, foods of animal origin, and the environment have been characterized by the detection of a set of virulence genes, pulsed-field gel electrophoresis (PFGE), and antibiotic susceptibility. All the strains examined were susceptible to all the antimicrobials tested. The Salmonella pathogenicity islands genes ssaQ, mgtC spi_4D, and sopB were present from 75.0% to 100% of the tested strains. Only one human and four environmental strains showed the avrA gene. The phage-related sopE1 gene was present in 93% of the strains, whereas sodC1 and gipA genes were only in four and two environmental strains, respectively. The bcfC fimbrial gene was present in all the animal/food strains, in the 71.4% of environmental strains, and in 46.8% of the human strains, respectively. Overall, we observed 10 distinct virulence profiles (VP), but VP1-2-3 included 99 out of 112 strains. PFGE showed that 103 out of 111 isolates were grouped in four major clusters and three minor clusters, whereas two strains were totally unrelated. The most represented PFGE clusters mainly correlated with the virulotypes are VP1, VP2, and VP3. Salmonella Napoli shows an array of virulence genes similar to other serovars considered of public health importance and confirming its capability to cause infection in human. Concerning possible source of infection or reservoirs, the results did not point out any, but our hypothesis is that the environment can act as the main reservoir for Salmonella Napoli, and from there it can spill over to animals and humans. Further studies are needed to increase the knowledge on the ecology of Salmonella Napoli serovar and on the main risk factors for human infection.


Asunto(s)
Microbiología Ambiental , Productos de la Carne/microbiología , Intoxicación Alimentaria por Salmonella/microbiología , Salmonelosis Animal/microbiología , Salmonella enterica/patogenicidad , Animales , Animales Domésticos/microbiología , Antibacterianos/farmacología , Reservorios de Enfermedades , Electroforesis en Gel de Campo Pulsado , Genes Bacterianos , Islas Genómicas , Humanos , Italia , Pruebas de Sensibilidad Microbiana , Filogenia , Salmonella enterica/efectos de los fármacos , Salmonella enterica/genética , Especificidad de la Especie , Virulencia , Factores de Virulencia/genética
11.
Microorganisms ; 9(12)2021 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-34946066

RESUMEN

Salmonellosis is the second most commonly reported gastrointestinal infection in humans after campylobacteriosis, and an important cause of foodborne outbreaks in the EU/EEA. The vast majority (72.4%) of the salmonellosis foodborne outbreaks reported in EU in 2019 were caused by Salmonella Enteritidis, even if their total number due to this serovar decreased. In spring 2020, a foodborne outbreak of S. Enteritidis occurred in the Marche region (Central Italy), involving 85 people. The common exposure source was a cheese, pecorino "primo sale", produced with raw sheep milk. The cheese batches were produced by two local dairies, with a livestock production facility, also including a sheep farm, being part of one dairy. Bacteriological analysis of samples collected allowed the detection of S. Enteritidis in animal faeces, environmental samples, raw-milk bulk tanks and milk taken from single animals. These data confirm that, despite the scarce scientific evidence, S. Enteritidis can infect sheep and be shed into the animals' milk. Hence, this is a real risk for public health when unpasteurized milk is used in production of such cheese. The present paper describes the results of the investigations conducted to clarify this outbreak.

12.
J Clin Microbiol ; 48(8): 2892-6, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20554809

RESUMEN

Recent evidence strongly suggests an association between the use of fluoroquinolones and Clostridium difficile infection (CDI). Resistance to fluoroquinolones has been described not only in the hypervirulent strain 027, but also in other important PCR ribotypes circulating in hospital settings. In a European prospective study conducted in 2005, strains resistant to moxifloxacin represented 37.5% of C. difficile clinical isolates. In this study, we investigated a sample of 147 toxigenic C. difficile isolates, collected in Italy from 1985 to 2008, for the presence of mutations in gyr genes that conferred resistance to fluoroquinolones based on a LightCycler assay. Results were confirmed by the determination of MICs for moxifloxacin. Strains resistant to moxifloxacin were also investigated for resistance to three other fluoroquinolones and for a possible association between fluoroquinolone and macrolide-lincosamide-streptogramin B resistance. C. difficile isolates were typed by PCR ribotyping. In total, 50 clinical isolates showed substitutions in gyr genes and were resistant to fluoroquinolones. Ninety-six percent of the C. difficile resistant isolates showed the substitution Thr82-to-Ile in GyrA, as already observed in the majority of resistant strains worldwide. A significant increase of resistance (P < 0.001) was observed in the period 2002 to 2008 (56% resistant) compared to the period 1985 to 2001 (10% resistant). Coresistance with erythromycin and/or clindamycin was found in 96% (48/50) of the isolates analyzed and, interestingly, 84% of resistant strains were erm(B) negative. The majority of the fluoroquinolone-resistant isolates belonged to PCR ribotype 126 or 018. PCR ribotype 126 was the most frequently found from 2002 to 2005, whereas PCR ribotype 018 was predominant in 2007 and 2008 and still represents the majority of strains typed in our laboratory. Overall, the results demonstrate an increasing number of C. difficile strains resistant to fluoroquinolones in Italy and changes in the prevalence and type of C. difficile isolates resistant to fluoroquinolones circulating over time.


Asunto(s)
Antibacterianos/farmacología , Clostridioides difficile/clasificación , Clostridioides difficile/efectos de los fármacos , Farmacorresistencia Bacteriana , Enterocolitis Seudomembranosa/epidemiología , Fluoroquinolonas/farmacología , Ribotipificación , Proteínas Bacterianas/genética , Técnicas de Tipificación Bacteriana , Clostridioides difficile/genética , Clostridioides difficile/aislamiento & purificación , Girasa de ADN/genética , Enterocolitis Seudomembranosa/microbiología , Humanos , Italia/epidemiología , Lincosamidas/farmacología , Macrólidos/farmacología , Pruebas de Sensibilidad Microbiana , Epidemiología Molecular , Reacción en Cadena de la Polimerasa/métodos , Estreptogramina B/farmacología
13.
J Clin Microbiol ; 48(6): 2103-9, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20410351

RESUMEN

During the 2000s, a new clonal group with resistances to ampicillin, streptomycin, sulfonamides, and tetracycline (ASSuT) emerged in Italy among strains of Salmonella enterica serovar Typhimurium and its monophasic variant, Salmonella enterica subspecies enterica serovar 4,[5],12:i:-. The PulseNet Europe database allowed us to identify ASSuT strains of both S. Typhimurium and its monophasic variant, isolated in Denmark and the United Kingdom, with the same or very closely related pulsed-field gel electrophoresis (PFGE) patterns as the Italian strains, suggesting that the ASSuT clonal group is circulating in different European countries. With the aim of analyzing the molecular basis of antibiotic resistance, resistance genes were identified and their localization was investigated in 66 ASSuT strains and, as controls, in 11 strains with different resistance patterns and PFGE profiles, belonging both to S. Typhimurium and to its monophasic variant, isolated from humans in Italy, Denmark, and the United Kingdom. All the ASSuT strains were positive for the following resistance genes: bla(TEM-1), strA-strB, sul2, and tet(B). A localization experiment demonstrated that the ASSuT resistance genes are chromosomally located. This study confirms that a multidrug-resistant clonal group, ASSuT, of S. Typhimurium and its monophasic variant has emerged and is circulating in Italy, Denmark, and the United Kingdom. Moreover, the results of this work demonstrate that the multidrug resistance in this clonal group of Salmonella strains is conferred by a new genomic island.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple , Genes Bacterianos , Islas Genómicas , Infecciones por Salmonella/microbiología , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/genética , Técnicas de Tipificación Bacteriana , Análisis por Conglomerados , Dermatoglifia del ADN , ADN Bacteriano/genética , Dinamarca , Electroforesis en Gel de Campo Pulsado , Genotipo , Humanos , Italia , Epidemiología Molecular , Salmonella typhimurium/clasificación , Salmonella typhimurium/aislamiento & purificación , Reino Unido
14.
Antibiotics (Basel) ; 9(11)2020 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-33207568

RESUMEN

This work aimed to evaluate the antimicrobial susceptibility of 87 Salmonella Infantis strains isolated in Italy from 2016 to 2019 along the food chain of broiler meat production and in humans and to determine the genetic profiles of the strains in order to establish a possible correlation with the antimicrobial pattern. All isolates were tested by the disk diffusion method to evaluate antimicrobial susceptibility toward sixteen antimicrobials, and the broth microdilution method was used to confirm extended spectrum ß-lactamase (ESBL) production. PCR and pulsed field gel electrophoresis (PFGE) were applied to characterize ESBL-encoding and AmpC ß-lactamase genes and to analyze the S. Infantis strains genetic profiles respectively. S. Infantis isolates showed high prevalence of resistance, in particular toward nalidixic acid (97.7%), tetracycline (96.5%), sulphamethoxazole/trimethoprim (91%) and cefepime (72.4%). The 80.5% of isolates were ESBL, cefotaxime-resistant, carrying the blaCTX-M1 gene. The most prevalent PFGE profile was XbaI.0126 (35.6%). The remaining strains had a genetic homology from 81% to 97% with the XbaI.0126 profile. The strains belonging to these profiles were isolated from different matrices collected along the broiler food chain independently on the year and from the region and there was no correlation between the PFGE profiles and resistance patterns. We found two ESBL-producing S. Infantis strains with the same XbaI.2621 profile isolated from humans and from poultry feces, not yet reported in Italy. Our findings confirmed the diffusion of ESBL-multi drug resistant (MDR) S. Infantis along the broiler food chain and in humans and underlined the importance of continuous monitoring to control and to reduce the prevalence of this bacterium, applying a global One Health approach.

15.
Antimicrob Agents Chemother ; 53(9): 4019-21, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19528272

RESUMEN

A qnrB19 gene variant, carried by an IncL/M-like plasmid, was detected in a multidrug Salmonella enterica serovar Typhimurium human strain with reduced susceptibility to ciprofloxacin. The genetic environment around the gene was fully sequenced (20 kb). A large gene cluster, containing the aph, qnrB19, and blaSHV-12-like resistance genes, is inserted inside a Tn3 transposon.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Plásmidos/genética , Quinolonas/farmacología , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/fisiología , Elementos Transponibles de ADN/genética , Evolución Molecular , Pruebas de Sensibilidad Microbiana , Familia de Multigenes/genética
16.
Foodborne Pathog Dis ; 6(6): 711-7, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19580448

RESUMEN

Salmonella enterica serovar Typhimurium (STM) represents the prevalent cause of foodborne gastroenteritis in Italy with the majority of isolates exhibiting multidrug resistance. A resistant pattern that includes ampicillin (A), streptomycin (S), sulfonamide (Su), and tetracycline (T) (ASSuT) but lacks resistance to chloramphenicol (C) has recently emerged in Italy among strains of STM and of its monophasic variant, S. enterica subspecies enterica serovar S. 4,[5],12:i:-. With the aim to evaluate their clonal relationships, 553 strains of STM and S. 4,[5],12:i:- with the ASSuT and ACSSuT resistance patterns isolated in Italy from human infections between 2003 and 2006 were characterized by pulsed-field gel electrophoresis (PFGE) according to the PulseNet-Europe protocol and nomenclature. Among both the STM and S. 4,[5],12:i:- ASSuT strains, the predominant PFGE profile was STYMXB.0079 (53.2-73.0% of strains, respectively), while the STM ACSSuT strains belonged to the STYMXB.0061 (37.2% of strains) and STYMXB.0067 (29.9% of strains). Bionumerics cluster analysis of the nonunique PFGE profiles showed that more than 90% of ASSuT and ACSSuT-resistant strains were included in two distinct clusters with a genetic homology of 73% each other, suggesting that the ASSuT-resistant strains belong to a same clonal lineage different from that of the ACSSuT strains. Phage typing showed that 23% of the ASSuT STM strains were not typeable and 22.3% were U302. The same phage types were observed among the ASSuT strains of S. 4,[5],12:i:-. A different figure was observed for the ACSSuT strains: the STM isolates mostly belonged to DT104 (70.2%), while none of the S. 4,[5],12:i:- strains belonged to this phage type. This study indicates that the tetra-resistant ASSuT strains of STM and S. 4,[5],12:i:-, increasingly isolated in Italy, belong to a same clonal lineage and that the S. 4,[5],12:i:- strains circulating in our country mainly derive from this STM clonal lineage.


Asunto(s)
Farmacorresistencia Bacteriana Múltiple/genética , Infecciones por Salmonella/microbiología , Salmonella typhimurium/genética , Resistencia a la Ampicilina/genética , Tipificación de Bacteriófagos , Electroforesis en Gel de Campo Pulsado , Variación Genética , Genotipo , Humanos , Italia , Pruebas de Sensibilidad Microbiana , Salmonella typhimurium/clasificación , Salmonella typhimurium/efectos de los fármacos , Estreptomicina , Sulfonamidas , Resistencia a la Tetraciclina/genética
17.
Microorganisms ; 7(9)2019 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-31546915

RESUMEN

The CRISPR-Cas adaptive immune system has been attracting increasing scientific interest for biological functions and biotechnological applications. Data on the Serratia marcescens system are scarce. Here, we report a comprehensive characterisation of CRISPR-Cas systems identified in S. marcescens strains isolated as secondary symbionts of Rhynchophorus ferrugineus, also known as Red Palm Weevil (RPW), one of the most invasive pests of major cultivated palms. Whole genome sequencing was performed on four strains (S1, S5, S8, and S13), which were isolated from the reproductive apparatus of RPWs. Subtypes I-F and I-E were harboured by S5 and S8, respectively. No CRISPR-Cas system was detected in S1 or S13. Two CRISPR arrays (4 and 51 spacers) were detected in S5 and three arrays (11, 31, and 30 spacers) were detected in S8. The CRISPR-Cas systems were located in the genomic region spanning from ybhR to phnP, as if this were the only region where CRISPR-Cas loci were acquired. This was confirmed by analyzing the S. marcescens complete genomes available in the NCBI database. This region defines a genomic hotspot for horizontally acquired genes and/or CRISPR-Cas systems. This study also supplies the first identification of subtype I-E in S. marcescens.

18.
Res Microbiol ; 158(1): 10-7, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17224257

RESUMEN

Salmonella enterica subsp. enterica serotype Enteritidis is not readily subtyped beyond the level of phage type (PT). Pulsed field gel electrophoresis (PFGE) is generally acknowledged to be the most discriminating typing method for Salmonella, but only a restricted variety of PFGE types has been described for S. enterica serotype Enteritidis. In the present study, a modification of the SE-AFLP typing method was used to investigate both outbreak and apparently sporadic isolates of S. enterica serotype Enteritidis belonging to different PTs and/or PFGE types. The method proved to be as discriminatory as PFGE when combined with phage typing, and provided subtyping data consistent with epidemiological information. Although the modified SE-AFLP typing method did not prove to achieve a superior discriminatory ability in resolving clusters, it has a high enough throughput for use in outbreak investigations. This method can be used in combination with other typing methods to obtain epidemiologically relevant subtyping data on S. enterica serotype Enteritidis.


Asunto(s)
Técnicas de Tipificación Bacteriana/métodos , Técnica del ADN Polimorfo Amplificado Aleatorio/métodos , Infecciones por Salmonella/microbiología , Salmonella enteritidis/clasificación , Cartilla de ADN , Humanos , Técnicas de Amplificación de Ácido Nucleico , Salmonella enteritidis/genética , Sensibilidad y Especificidad
19.
Microb Drug Resist ; 13(1): 37-43, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17536932

RESUMEN

In this study 45 epidemic and sporadic isolates of Acinetobacter baumannii were investigated by antimicrobial resistance, integron identifications and genotyping. Isolates were genotyped by random amplified polymorphism (RAPD) DNA and pulsed-field gel electrophoresis (PFGE). Four different RAPD patterns were observed among the isolates of our collection, further discerned in six PFGE types. Two prevalent genotypes were identified, one corresponding to a carbapenem resistant epidemic clone, causing an outbreak at the intensive care unit of a hospital of Rome. Two class 1 integrons, carrying different gene cassette arrays, were identified among the two prevalent genotypes. Nucleotide analysis of the integron-variable regions revealed the presence of the aacA4, orfO, bla(OXA-20), and aacC1, orfX, orfX', aadA1 gene cassette arrays, respectively. All the carbapenem resistant strains analyzed in this study carried the bla (OXA-58) gene located on plasmids.


Asunto(s)
Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/genética , Antibacterianos/farmacología , Carbapenémicos/farmacología , Brotes de Enfermedades , Resistencia betalactámica/genética , beta-Lactamasas/genética , Acinetobacter baumannii/aislamiento & purificación , Técnicas Bacteriológicas , Electroforesis en Gel de Campo Pulsado , Genotipo , Humanos , Integrones , Unidades de Cuidados Intensivos , Técnica del ADN Polimorfo Amplificado Aleatorio , Ciudad de Roma/epidemiología
20.
BMC Infect Dis ; 7: 62, 2007 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-17587439

RESUMEN

BACKGROUND: Shigella spp. are major cause of diarrhoeal disease in both developing and developed countries. Shigella sonnei is the serogroup of Shigella most frequently responsible for sporadic and epidemic enteritis in developed countries. In recent years the emergence and spread of S. sonnei biotype g carrying class 2 integron have been frequently reported in many countries. Recently, S. sonnei has been reported as the prevalent serogroup of Shigella in Iran. The present study was carried out to investigate phenotypic and genetic characteristics of Shigella sonnei isolates identified in the years 2002 and 2003 in Tehran, Iran. METHODS: Biotyping, drug susceptibility testing, pulsed field gel electrophoresis (PFGE) and analysis of class 2 integrons have been carried out on 60 S. sonnei isolates, including 57 sporadic isolates from paediatric cases of shigellosis occurring in 2002 and 2003, two sporadic isolates recovered in 1984 and the ATCC 9290 strain. RESULTS: Biotype g and resistance to streptomycin, sulfamethoxazole-trimethoprim and tetracycline were exhibited by 54 of the 57 recent isolates. Of the 54 biotype g isolates, 28 exhibited a class 2 integron of 2161 bp, and 24 a class 2 integron of 1371 bp, respectively. Class 2 integrons were not detected in four isolates only, including the two endemic isolates recovered in 1984 and two strains from recent sporadic cases. PFGE divided the strains into eight pulsotypes labeled A to H, three major pulsotypes - A to C - including the large majority of the recent sporadic S. sonnei isolates. Pulsotypes A and C were the most prevalent groups, accounting for 41.6% and 35.0%, respectively, of the isolates under study. CONCLUSION: The results suggest that biotype g, class 2 integron carrying S. sonnei are prevalent in our geographic area. S. sonnei isolated in the years 2002 and 2003 could be attributed to a few predominant clusters including, respectively, strains with pulsotypes B and C carrying a 2161 bp class 2 integron, and those having pulsotype A and a 1371 bp class 2 integron. A few epidemic clones are responsible for the apparently endemic occurrence of shigellosis in Tehran, Iran.


Asunto(s)
Disentería Bacilar/genética , Integrones/genética , Shigella sonnei/clasificación , Shigella sonnei/genética , Farmacorresistencia Bacteriana , Disentería Bacilar/clasificación , Disentería Bacilar/epidemiología , Enfermedades Endémicas , Genotipo , Humanos , Irán/epidemiología , Fenotipo , Prevalencia
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