scholarly journals Laboratory Typing Methods for Diagnostic of Salmonella Strains, the “Old” Organism That Continued Challenges

Author(s):  
Ben Salem ◽  
Mzoughi Ridha ◽  
Aouni Mahjoub
Keyword(s):  
2021 ◽  
Vol 11 (4) ◽  
pp. 1595
Author(s):  
Salvatore La China ◽  
Luciana De Vero ◽  
Kavitha Anguluri ◽  
Marcello Brugnoli ◽  
Dhouha Mamlouk ◽  
...  

Bacterial cellulose (BC) is receiving a great deal of attention due to its unique properties such as high purity, water retention capacity, high mechanical strength, and biocompatibility. However, the production of BC has been limited because of the associated high costs and low productivity. In light of this, the isolation of new BC producing bacteria and the selection of highly productive strains has become a prominent issue. Kombucha tea is a fermented beverage in which the bacteria fraction of the microbial community is composed mostly of strains belonging to the genus Komagataeibacter. In this study, Kombucha tea production trials were performed starting from a previous batch, and bacterial isolation was conducted along cultivation time. From the whole microbial pool, 46 isolates were tested for their ability to produce BC. The obtained BC yield ranged from 0.59 g/L, for the isolate K2G36, to 23 g/L for K2G30—which used as the reference strain. The genetic intraspecific diversity of the 46 isolates was investigated using two repetitive-sequence-based PCR typing methods: the enterobacterial repetitive intergenic consensus (ERIC) elements and the (GTG)5 sequences, respectively. The results obtained using the two different approaches revealed the suitability of the fingerprint techniques, showing a discrimination power, calculated as the D index, of 0.94 for (GTG)5 rep-PCR and 0.95 for ERIC rep-PCR. In order to improve the sensitivity of the applied method, a combined model for the two genotyping experiments was performed, allowing for the ability to discriminate among strains.


1999 ◽  
Vol 20 (11) ◽  
pp. 756-758 ◽  
Author(s):  
Jeffrey D. Klausner ◽  
Carol Zukerman ◽  
Ajit P. Limaye ◽  
Lawrence Corey

AbstractUsing molecular typing methods, we confirmed an outbreak ofStenotrophomonas maltophiliaamong bone marrow transplant patients. The likely source was a healthcare worker who may have washed with moisturizer instead of soap between patients. Hospital epidemiologists need to go beyond antibiograms when evaluating outbreaks and be vigilant about all aspects of hand washing.


Medicine ◽  
2015 ◽  
Vol 94 (37) ◽  
pp. e1534 ◽  
Author(s):  
Marcela Rodriguez ◽  
Patrick G. Hogan ◽  
Sarah W. Satola ◽  
Emily Crispell ◽  
Todd Wylie ◽  
...  

2013 ◽  
Vol 62 (5) ◽  
pp. 701-707 ◽  
Author(s):  
Jia-Li Feng ◽  
Jin-Yan Lin ◽  
Xiao-Bing Jiang ◽  
Ou Zhang ◽  
Jiang-Feng Zhu ◽  
...  

Laribacter hongkongensis is a potential emerging pathogen, associated with community-acquired diarrhoea. For epidemiological purposes, different molecular typing methods, such as pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing, have been developed for this pathogen. However, these methods require specialized equipment and costly reagents. More importantly, they are labour-intensive and time-consuming, which is not really suitable for foodborne disease outbreak investigations. In this study, we developed a rapid and reliable method using 22-mer primers specific for the enterobacterial repetitive intergenic consensus sequence (ERIC). PFGE was used for comparison, to evaluate this method. A total of 81 isolates of L. hongkongensis were examined: 79 isolates recovered from food of diverse origins and two strains derived from patients with L. hongkongensis-associated infection. Typing patterns and clustering analysis indicated that the 81 L. hongkongensis isolates were grouped into 21 and 13 genotypes by ERIC-PCR and PFGE, respectively. ERIC-PCR was found as reproducible as PFGE. A high percentage (70.4 %) of isolates yielded distinguishable ERIC-PCR patterns, which were concordant with the results from PFGE. These results suggest that ERIC-PCR is valuable for use in the epidemiological investigation of L. hongkongensis.


2018 ◽  
Vol 6 (15) ◽  
pp. e00295-18
Author(s):  
Alexander Fortuna ◽  
Ricardo Ramnarine ◽  
Aimin Li ◽  
Nahuel Fittipaldi ◽  
Christine Frantz ◽  
...  

ABSTRACT Legionella pneumophila outbreak investigations require the development of reliable typing methods to better understand the genetic relationships of the isolates involved. Here, we report the draft genome sequences of four clinical Legionella pneumophila isolates obtained between 2000 and 2012 in Ontario, Canada.


1993 ◽  
Vol 111 (2) ◽  
pp. 257-264 ◽  
Author(s):  
G. O'Neill ◽  
J. E. Adams ◽  
R. A. Bowman ◽  
T. V. Riley

SummaryIt is generally accepted that most patients withClostridium difficile-associated diarrhoea acquire the organism from the environment. Recently we demonstrated that household pets may constitute a significant reservoir ofC. difficilethrough gastrointestinal carriage in up to 39% of cats and dogs. These findings suggested that direct transmission from household pets, or contamination of the environment by them, may be a factor in the pathogenesis ofC. difficile-associated diarrhoea. To investigate this possibility, we examined isolates ofC. difficilefrom humans, pets and the environment by restriction enzyme analysis (REA) and restriction fragment length polymorphism (RFLP) typing using enhanced chemiluminescence. Both REA and RFLP typing methods usedHindIII digests of chromosomal DNA. A total of 116 isolates ofC. difficilefrom pets (26), veterinary clinic environmental sites (33), humans (37) and hospital environmental sites (20) was examined. REA was far more discriminatory than RFLP typing and for all isolates there were 34 REA types versus 6 RFLP types. There was good correlation between the REA types found in isolates from pets and from the veterinary clinic environment, and between isolates from humans and from those found in the hospital environment. There was, however, no correlation between REA type ofC. difficilefound in pets and isolates of human origin. We conclude that there may still be a risk of humans acquiringC. difficilefrom domestic pets as these findings may be the result of geographical variation.


2021 ◽  
Vol 9 (3) ◽  
pp. 661
Author(s):  
Adriana Calderaro ◽  
Mirko Buttrini ◽  
Monica Martinelli ◽  
Benedetta Farina ◽  
Tiziano Moro ◽  
...  

Typing methods are needed for epidemiological tracking of new emerging and hypervirulent strains because of the growing incidence, severity and mortality of Clostridioides difficile infections (CDI). The aim of this study was the evaluation of a typing Matrix-Assisted Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS (T-MALDI)) method for the rapid classification of the circulating C. difficile strains in comparison with polymerase chain reaction (PCR)-ribotyping results. Among 95 C. difficile strains, 10 ribotypes (PR1–PR10) were identified by PCR-ribotyping. In particular, 93.7% of the isolates (89/95) were grouped in five ribotypes (PR1–PR5). For T-MALDI, two classifying algorithm models (CAM) were tested: the first CAM involved all 10 ribotypes whereas the second one only the PR1–PR5 ribotypes. Better performance was obtained using the second CAM: recognition capability of 100%, cross-validation of 96.6% and agreement of 98.4% (60 correctly typed strains, limited to PR1–PR5 classification, out of 61 examined strains) with PCR-ribotyping results. T-MALDI seems to represent an alternative to PCR-ribotyping in terms of reproducibility, set up time and costs, as well as a useful tool in epidemiological investigation for the detection of C. difficile clusters (either among CAM included ribotypes or out-of-CAM ribotypes) involved in outbreaks.


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