Characterization of Listeria monocytogenes on Retail Food from Jiangsu Province, China

2013 ◽  
Vol 781-784 ◽  
pp. 1332-1335
Author(s):  
Tao Yu

Listeria monocytogenes isolates recovered from retail foods were characterized by serotyping, genotyping using pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility testing. Six serotypes were identified among the isolates and the predominant serotype was 1/2a (42, 48.8%). PFGE differentiated the 86 isolates into 23 ApaI restriction patterns. Twenty-five (29.1%) of the L.monocytogenes strains exhibited resistance to at least one antimicrobial. Resistance to ciprofloxacin (17.4% of the isolates were resistant) and resistance to tetracycline (17.4%) were observed frequently.

2002 ◽  
Vol 19 (1) ◽  
pp. 47-55 ◽  
Author(s):  
M Gianfranceschi ◽  
M Pourshaban ◽  
A Gattuso ◽  
C Wedell-Neergaard ◽  
P Aureli

1993 ◽  
Vol 39 (4) ◽  
pp. 395-401 ◽  
Author(s):  
C. Buchrieser ◽  
R. Brosch ◽  
B. Catimel ◽  
J. Rocourt

Recent food-borne outbreaks of human listeriosis as well as numerous sporadic cases have been mainly caused by Listeria monocytogenes serovar 4b strains. Thus, it was of interest to find out whether a certain clone or a certain few clones were responsible for these cases and especially for outbreaks., We used pulsed-field gel electrophoresis of large chromosomal DNA restriction fragments generated by ApaI, SmaI, or NotI to analyse 75 L. monocytogenes strains isolated during six major and eight smaller recent listeriosis outbreaks. These strains could be divided into 20 different genomic varieties. Thirteen of 14 strains isolated during major epidemics in Switzerland (1983–1987), the United States (California, 1985) and Denmark (1985–1987) demonstrated indistinguishable DNA restriction patterns. In contrast, strains responsible for the outbreaks in Canada (Nova Scotia, 1981), the United States (Massachusetts, 1983), France (Anjou, 1975–1976), New Zealand (1969), and Austria (1986) and some smaller outbreaks in France (1987, 1988, 1989) were each characterized by particular combinations of DNA restriction patterns. Seventy-seven percent of the tested strains could be classified into the previously described ApaI group A (Brosch et al. 1991), demonstrating a very close genomic relatedness. Because 49% of the epidemic strains selected for this study belonged to phagovar 2389/2425/3274/2671/47/108/340 or 2389/47/108/340, fifty-six additional strains of these phagovars, isolated from various origins, were also typed to determine whether differences in DNA restriction profiles between epidemic and randomly selected strains of the same phagovars could be pointed out. Variations in DNA patterns appeared more frequently within randomly selected strains than within epidemic strains.Key words: Listeria monocytogenes, listeriosis, typing, pulsed-field gel electrophoresis, epidemic.


2006 ◽  
Vol 69 (6) ◽  
pp. 1297-1303 ◽  
Author(s):  
M. WAGNER ◽  
F. ELISKASES-LECHNER ◽  
P. RIECK ◽  
I. HEIN ◽  
F. ALLERBERGER

One hundred eighty-one small-scale cheese factories (annual production <100,000 kg) were tested for the presence of Listeria monocytogenes in cheese and smear samples from 1997 to 2000. In total, 2615 samples were drawn. Fifty (27.6%) of 181 enterprises yielded L. monocytogenes. From 14 of the cheese-making facilities, we obtained more than four L. monocytogenes isolates. A total of 182 mostly cheese- and smear-borne L. monocytogenes strains were characterized by serotyping and pulsed-field gel electrophoresis. In 12 of 14 cheese factories, over half of the L. monocytogenes isolates were genetically indistinguishable by pulsetype. On average, genetically indistinguishable isolates were recovered for 11.9 months. Regarding serotypes, 27.3% of the isolates were of serovar 4b. Inadequate personal hygiene could explain the high prevalence of serovar 4b isolates in small-scale cheesemaking facilities. Forty-two percent of the serovar 4b isolates recovered from epidemiologically unlinked facilities (in comparison to 40 and 29% of the 1/2a and 1/2b isolates, respectively) were genetically indistinguishable from at least one other isolate. Indistinguishable serovar 1/2a and 1/2b isolates belonged to five and six different pulsetypes, respectively, whereas serovar 4b isolates belonged to only two pulsetypes. This finding suggested a wide distribution of genetically homologous serovar 4b isolates among the facilities tested in our study.


2019 ◽  
Vol 7 (3) ◽  
pp. 64 ◽  
Author(s):  
Kazuki Harada ◽  
Takae Shimizu ◽  
Hiroichi Ozaki ◽  
Yui Kimura ◽  
Tadashi Miyamoto ◽  
...  

In many countries including Japan, the status of emerging antimicrobial resistance among Serratia spp. and Citrobacter spp. in companion animals remains unknown because these genera are rarely isolated from animals. In this study, 30 Serratia spp. and 23 Citrobacter spp. isolates from companion animals underwent susceptibility testing for 10 antimicrobials. Phenotypic and genetic approaches were used to identify the mechanisms of extended-spectrum cephalosporins (ESC). Subsequently, ESC-resistant Citrobacter spp. strains underwent multilocus sequence typing and pulsed-field gel electrophoresis (PFGE). A significantly higher rate (34.8%) of ESC resistance was observed in Citrobacter spp. isolates than in Serratia spp. isolates (0%). ESC resistance was detected in five C. freundii strains, two C. portucalensis strains, and one C. koseri strain. All of the ESC-resistant Citrobacter spp. strains harbored CMY-type and/or DHA-type AmpC β-lactamases. Three C. freundii strains harbored the CTX-M-3-type extended-spectrum β-lactamases. Notably, the three blaCTX-3-producing and two blaCMY-117-bearing C. freundii strains (obtained from different patients in one hospital) had the same sequence type (ST156 and ST18, respectively) and similar PFGE profiles. We believe that ESC-resistant Citrobacter spp. are important nosocomial pathogens in veterinary medicine. Therefore, infection control in animal hospitals is essential to prevent dissemination of these resistant pathogens.


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