35 research outputs found
Antimicrobial resistance trends in equine population of Central Italy for Streptococcus equi subsp. zooepidemicus
No full textMolecular typing of Salmonella enterica subspecies enterica serovar Typhimurium isolated in Abruzzo region (Italy) from 2008 to 2010
No full textIn this study, 47 antibiotic-resistant strains of Salmonella enterica subspecies enterica serovar Typhimurium (ST) were characterised, including 15 monophasic variants 1, 4, [5], 12:i:-, (STm) isolated from different matrices. They were all selected from 389 Salmonella enterica subspecies enterica strains isolated during 2008-2010 in Abruzzo region (Italy). Thirty-seven strains showed to be resistant to more than 1 antibiotic. Among 47 isolates, phage type U311 and DT104 were identified. The ASSuT resistance pattern was predominant in mST strains and ACSSuT in ST DT104 and U302. A multiplex Polimerase Chain Reaction (PCR) method was used to investigate 4 genes: fluorfenicol (floSt), virulence (spvC), invasine (invA) and integrase (int). All ST the strain were positive for invA gene and 28,32% of strains were positive for spvC gene. PFGE analysis revealed a large number of small clonal populations, however not ascrivable to outbreaks
Prevalence of netB-positive Clostridium perfringens in Italian poultry flocks by environmental sampling
No full textClostridium perfringens type G is one of the pathogens involved in enteric diseases in poultry. NetB, a poreforming toxin, is considered the main virulence factor responsible for necrotic enteritis during C. perfringens infection. We
carried out a field study involving 14 farms to evaluate the occurrence of netB-positive C. perfringens and the impact of
infection in Italian poultry flocks. Environmental samples (n = 117) and 50 carcasses were screened by microbiologic and molecular methods. Microbiologic investigations yielded 82 C. perfringens isolates. DNA was extracted from all samples and screened for α-toxin and NetB encoding genes by real-time PCR. The C. perfringens α-toxin gene was detected in 151 of 167 extracts (90.4%), and 31 of 151 (20.5%) were netB gene positive also. Sixteen isolates from a turkey flock with mild enteric disorders were also netB positive, demonstrating their occurrence not only in broiler but also in turkey flocks. A pulsed-field gel electrophoresis protocol was optimized to evaluate the diversity among isolates and revealed high genetic heterogeneity. The complete NetB toxin-coding gene of 2 C. perfringens isolates from turkey and broiler flocks were analyzed and showed very high relatedness with analogous sequences worldwide
Studio epidemiologico di un focolaio da Norovirus rilevato nel 2009 in una residenza assistita per anziani in Italia Centrale
No full textIn una residenza assistita per anziani, nella regione Abruzzo, in Italia Centrale, tra gennaio e marzo 2009, è stato riscontrato un focolaio da Norovirus genotipo GII.4 (variante 2006). Le indagini condotte nella residenza, tipologicamente esposta a infezioni da Norovirus, come riportato con frequenza in letteratura, si sono concentrate sull'individuazione della fonte d'infezione e della via di propagazione del virus. Sono stati effettuati controlli igienico-sanitari e analisi microbiologiche e chimiche sul sistema idrico della struttura, su ospiti e operatori della residenza. Per conoscere le condizioni relative all'insorgenza dell'infezione e alla diffusione dell'agente patogeno è stato realizzato ed erogato un questionario finalizzato a individuare le abitudini di vita dei soggetti presenti nella residenza
Indagine preliminare sulla resistenza ai fluorochinoloni in ceppi di Escherichia coli resistenti all’acido nalidixico isolati da feci animali
No full textE’ stata valutata la possibile resistenza ai fluorochinoloni in 17 ceppi di Escherichia coli resistenti all'acido nalidixico, isolati da feci animali. Sono state impiegate tecniche di PCR, RFLP, ibridazione, e sequenziamento allo scopo di evidenziare la presenza di mutazioni puntiformi nelle subunità A e B della DNA girasi e possibile la presenza del gene qnr a testimonianza di eventuale resistenza plasmidica. In 10 dei 17 ceppi di E. coli esaminati è stata evidenziata una resistenza di tipo cromosomico con la presenza di integroni di classe I e in nessuno di essi è stata evidenziata la presenza del gene qnr. In 6 ceppi è stata osservata la mutazione Ser83-Leu e in un ceppo la mutazione Ser83-Ala. Non sono state evidenziate le mutazioni note ai codoni Asp87 di gyrA e Asp426 e Asp477 di gyrB. Dal sequenziamento del ceppo di E. coli ATCC 25922 sottoposto ad induzione di resistenza è stata rilevata una mutazione in gyrB al residuo Lys 447 che è stato sostituito da una Arginina
Preliminary investigations into fluoroquinolone resistance in Escherichia coli strains resistant to nalidixic acid isolated from animal faeces
No full textResistance to fluoroquinolones was evaluated in 17 nalidixic acid-resistant Escherichia coli strains isolated from animal faeces. Polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP), hybridisation and sequencing were used to reveal point mutations in DNA gyrase subunits A and B and the presence of the qnr gene as evidence of plasmid resistance. Chromosomal resistance and class 1 integrons were found in 10 of the 17 E. coli strains examined, while the qnr gene was not found in any of these. Mutation Ser83-Leu was found in six strains and in one strain mutation Ser83-Ala was found in gyrA. Mutations in gyrA Asp87 codons and in gyrB Asp426 or Lys 447 codons were not identified. Sequencing of the E. coli strain ATCC 25922 subjected to resistance induction revealed a gyrB mutation of the Lys 447 residue which had been replaced by arginine
Polymerase chain reaction and bacteriological comparative analysis of raw milk samples and buffalo mozzarella produced and marketed in Caserta in the Campania region of Italy
No full textTo help identify an epidemiological link between the consumption of buffalo mozzarella prepared with raw milk (not heat-treated) and cases of human brucellosis, 80 samples of raw buffalo milk and 315 samples of mozzarella were tested for the presence of Brucella spp. Samples originated from Caserta, the province with the highest number of Brucella-positive buffalo herds in Campania, the region in which 96.02% of all cases of human brucellosis reported in 2000-2005 were recorded. To take into account possible seasonal variations, between February 2006 and March 2007, samples were purchased directly from 72 dairy outlets that were representative of the province. Samples were tested for Brucella spp. using the polymerase chain reaction (PCR) and bacterial isolation. Samples tested negative for Brucella using both methods. Spiked samples were then prepared and tested by PCR and bacterial isolation and the sensitivity, specificity, repeatability, reproducibility and limit of detection were determined. The PCR limit of detection was below 1 colony-forming unit (cfu)/g. The repeatability and reproducibility of the method were 100% (p = 0.95), the sensitivity was 96.7% (p = 0.95) and the specificity was 100% (p = 0.95)
Comparazione fra polymerase chain reaction e isolamento batteriologico in campioni di latte crudo e mozzarella di bufala prodotta in provincia di Caserta, regione Campania (Italia)
No full textPer contribuire all’individuazione di un possibile nesso epidemiologico tra consumo di mozzarella di bufala preparata con latte crudo (non trattato al calore) e casi di brucellosi umana, sono stati analizzati, per ricerca di Brucella spp., 80 campioni di latte bufalino crudo e 315 campioni di mozzarella. Gli alimenti esaminati sono stati prelevati in caseifici della provincia di Caserta dove è presente la più alta concentrazione di allevamenti bufalini sierologicamente positivi alla brucellosi in Campania, regione che, nel periodo 2000-2005, ha registrato il 96,02% dei casi di brucellosi umana notificati in Italia. Al fine de valutare possibili variazioni stagionali, i campioni sono stati acquistati in 72 rivendite associate a caseifici nel periodo febbraio 2006-marzo 2007. La ricerca di Brucella spp. è stata effettuata utilizzando polymerase chain reaction (PCR) ed eseguendo contemporaneamente l’isolamento microbiologico. I campioni esaminati sono risultati negativi alla ricerca di Brucella con entrambi i metodi utilizzati. Sono stati, inoltre, definiti i parametri di sensibilità, specificità, ripetibilità, riproducibilità e il limite di rilevazione del metodo molecolare, esaminando campioni artificialmente contaminati, sia con metodo PCR sia con isolamento microbiologico classico. Il limite di rilevazione è risultato inferiore a 1 UFC/g, ripetibiltà e riproducibilità sono stati pari a 100% (p=0,95), sensibilità a 96,7% (p=0,95) e specificità a 100% (p=0,95)
Typing of Brucella field strains isolated from livestock populations in Italy between 2001 and 2006
No full textThe identification of species and biovars of Brucella field strains isolated in outbreaks is essential to fully understand the epidemiology of the disease and to trace sources of infection, thereby improving the outcome of brucellosis eradication programmes. It is important to identify the presence of Brucella strains in livestock populations and to determine the presence of new strains that might previously have been considered exotic. In this study, 732 Brucella strains isolated from livestock were submitted for typing by the Italian Istituti Zooprofilattici Sperimentali to the National Reference Laboratory for brucellosis between 2001 and 2006. Animal species affected, biovars typed and spatial distribution of isolates are discussed. Brucella field strains were identified using both conventional bacteriological methods and molecular techniques. Species identification was performed using the AMOS (AbortusMelitensisOvisSuis)-polymerase chain reaction. For biovar identification, amplification of omp2a, omp2b and omp31 genes was performed, followed by restriction fragment length polymorphism. Final biovar identification was performed by growth in the presence of basic fuchsin and thionin, using the slide agglutination test with Brucella A- and M- specific antisera
Characterization of Antimicrobial Resistance Patterns and Detection of Virulence Genes in Campylobacter Isolates in Italy
No full textCampylobacter has developed resistance to several antimicrobial agents over the years, including macrolides, quinolones and fluoroquinolones, becoming a significant public health hazard. A total of 145 strains derived from raw milk, chicken faeces, chicken carcasses, cattle faeces and human faeces collected from various Italian regions, were screened for antimicrobial susceptibility, molecular characterization (SmaI pulsed-field gel electrophoresis) and detection of virulence genes (sequencing and DNA microarray analysis). The prevalence of C. jejuni and C. coli was 62.75% and 37.24% respectively. Antimicrobial susceptibility revealed a high level of resistance for ciprofloxacin (62.76%), tetracycline (55.86%) and nalidixic acid (55.17%). Genotyping of Campylobacter isolates using PFGE revealed a total of 86 unique SmaI patterns. Virulence gene profiles were determined using a new microbial diagnostic microarray composed of 70-mer oligonucleotide probes targeting genes implicated in Campylobacter pathogenicity. Correspondence between PFGE and microarray clusters was observed. Comparisons of PFGE and virulence profiles reflected the high genetic diversity of the strains examined, leading us to speculate different degrees of pathogenicity inside Campylobacter populations
