Antibiotic Resistance and Molecular Analysis of Staphylococcus aureus Isolated from Cow's Milk and Dairy Products in Northeast Brazil

2014 ◽  
Vol 77 (4) ◽  
pp. 583-591 ◽  
Author(s):  
VLADIMIR M. SILVEIRA-FILHO ◽  
ISABELLE S. LUZ ◽  
ANA PAULA F. CAMPOS ◽  
WELLINGTON M. SILVA ◽  
MARIA PALOMA S. BARROS ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Gel Electrophoresis ◽  
Dairy Products ◽  
Pulsed Field Gel Electrophoresis ◽  
Staphylococcal Enterotoxin ◽  
Cow’S Milk ◽  
Northeast Brazil ◽  
Pulsed Field ◽  
Enterotoxin Genes

This work aimed to assess the clonal distribution among 94 strains of Staphylococcus aureus isolated from cow's milk, raw cheese, and a milking machine in 12 dairy farms in northeast Brazil, by analyzing different typing methods and detecting resistance and toxigenic profiles. For the first time, isolates of this region were assessed simultaneously by the polymorphism of the 3′ -end coa gene and 16S-23S rDNA, pulsed-field gel electrophoresis, antibiotic resistance phenotyping, and toxigenic arsenal. Although pulsed-field gel electrophoresis patterns showed a wider variation (discriminatory index 0.83) than the PCR-based methods, the internal transcribed spacer–PCR proved to be a useful and inexpensive procedure for conducting epidemiological surveys of S. aureus on a regional scale. Each dairy farm had its own resistance profile, and in two herds, 63% of the strains were multiresistant, probably due to the indiscriminate use of antibiotics in bovine mastitis treatment. No methicillin-resistant S. aureus strains were detected in this study; however, 93.6% of S. aureus strains harbored variable profiles of staphylococcal enterotoxin genes seg, seh, sei, and sej. Transcriptional analysis revealed that 53.3% of staphylococcal enterotoxin genes actually transcribed, pointing out the food poisoning risk of these dairy products to consumers in the region. Based on the detection of the most prevalent clones in a herd or region, appropriate antibiotic therapy and specific immunization can be used for the treatment and control of staphylococcal mastitis.

Plasmid Profiles and Pulsed-Field Gel Electrophoresis for Type A Enterotoxigenic Staphylococcus aureus Isolated from Foods

1995 ◽  
Vol 58 (2) ◽  
pp. 147-153 ◽  
Author(s):  
HAU-YANG TSEN ◽  
GEE-KAITE YU ◽  
IN-TING LIN
Keyword(s):  
Staphylococcus Aureus ◽  
Gel Electrophoresis ◽  
Food Samples ◽  
Pulsed Field Gel Electrophoresis ◽  
Staphylococcal Enterotoxin ◽  
Penicillin G ◽  
Staphylococcal Enterotoxin A ◽  
Chromosomal Dna ◽  
Pulsed Field ◽  
Plasmid Profiles

Reports regarding the use of plasmid profile and pulsed-field gel electrophoresis (PFGE) in subtyping of specific enterotoxigenic Staphylococcus aureus isolated from food samples are limited. We isolated 176 strains of S. aureus from food samples and showed that 64 of these strains are enterotoxigenic as determined by staphylococcal enterotoxin A, B, C, D detection kit by reversed passive latex agglutination (SET-RPLA) method. Of these 64 enterotoxigenic strains, 45 by SET-RPLA or 44 by polymerase chain reaction (PCR) were identified to be staphylococcal enterotoxin A (SEA) producing strains. All these 64 enterotoxigenic strains could be grouped into three patterns of antibiogram when their antibiotic susceptibilities to penicillin G, oxacillin, vancomycin and methicillin were investigated. Strains resistant to penicillin G, but susceptible to the other three antibiotics were of the major pattern since 50 of the 64 enterotoxigenic strains tested showed such pattern of antibiotic susceptibility. Plasmid deoxyribonucleic acid (DNA) analysis for the 45 SEA strains showed that four types of plasmid profiles could be obtained. When chromosomal DNA of these SEA strains were digested with Smal and subjected to the PFGE analysis, a total of eight genome types were observed. In addition, 28 of these 45 SEA strains tested could be grouped into one specific type of these eight genome types. Results shown in this report may be useful for the epidemiological study and for the tracing of contamination source when a food poisoning outbreak occurs.

scholarly journals Use of Pulsed-Field Gel Electrophoresis to Determine the Source of Methicillin-Resistant Staphylococcus aureus Bacteremia

2021 ◽  
Vol 13 (3) ◽  
pp. 602-610
Author(s):  
Eugene Y. H. Yeung ◽  
Ivan Gorn
Keyword(s):  
Staphylococcus Aureus ◽  
Gel Electrophoresis ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Epidemiological Studies ◽  
Pelvic Trauma ◽  
Pulsed Field Gel Electrophoresis ◽  
Bacterial Strains ◽  
Methicillin Resistant ◽  
Pulsed Field ◽  
Clinical Cases

Pulsed-field gel electrophoresis (PFGE) has historically been considered the gold standard in fingerprinting bacterial strains in epidemiological studies and outbreak investigations; little is known regarding its use in individual clinical cases. The current study detailed two clinical cases in which PFGE helped to determine the source of their methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. Patient A was found to have MRSA bacteremia after trauma in her pelvic area. MRSA was also found in her groin but not in her nostril and rectum. PFGE was performed that showed variable bands of her MRSA isolates from blood and groin, suggestive of different strains of MRSA. Her MRSA bacteremia was determined to be unrelated to her pelvic trauma. Patient B was found to have MRSA bacteremia after colonoscopy. MRSA was also found in his nostril and rectum. PFGE was performed that showed variable bands of his MRSA isolates from blood and rectum but identical bands of MRSA isolates from his blood and nostril. His MRSA bacteremia was determined to be unrelated to his colonoscopy procedure. The current study demonstrates the use of PFGE to rule out the source of bacteremia in individual clinical cases.

scholarly journals Assessment of Resolution and Intercenter Reproducibility of Results of Genotyping Staphylococcus aureus by Pulsed-Field Gel Electrophoresis of SmaI Macrorestriction Fragments: a Multicenter Study

1998 ◽  
Vol 36 (6) ◽  
pp. 1653-1659 ◽  
Author(s):  
Alex van Belkum ◽  
Willem van Leeuwen ◽  
Mary Elizabeth Kaufmann ◽  
Barry Cookson ◽  
Françoise Forey ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Gel Electrophoresis ◽  
Pulsed Field Gel Electrophoresis ◽  
Pfge Type ◽  
Data Sets ◽  
Bacterial Typing ◽  
Technical Problems ◽  
Pulsed Field ◽  
Pattern Similarity ◽  
Percent Similarity

Twenty well-characterized isolates of methicillin-resistantStaphylococcus aureus were used to study the optimal resolution and interlaboratory reproducibility of pulsed-field gel electrophoresis (PFGE) of DNA macrorestriction fragments. Five identical isolates (one PFGE type), 5 isolates that produced related PFGE subtypes, and 10 isolates with unique PFGE patterns were analyzed blindly in 12 different laboratories by in-house protocols. In several laboratories a standardized PFGE protocol with a commercial kit was applied successfully as well. Eight of the centers correctly identified the genetic homogeneity of the identical isolates by both the in-house and standard protocols. Four of 12 laboratories failed to produce interpretable data by the standardized protocol, due to technical problems (primarily plug preparation). With the five related isolates, five of eight participants identified the same subtype interrelationships with both in-house and standard protocols. However, two participants identified multiple strain types in this group or classified some of the isolates as unrelated isolates rather than as subtypes. The remaining laboratory failed to distinguish differences between some of the related isolates by utilizing both the in-house and standardized protocols. There were large differences in the relative genome lengths of the isolates as calculated on the basis of the gel pictures. By visual inspection, the numbers of restriction fragments and overall banding pattern similarity in the three groups of isolates showed interlaboratory concordance, but centralized computer analysis of data from four laboratories yielded percent similarity values of only 85% for the group of identical isolates. The differences between the data sets obtained with in-house and standardized protocols could be the experimental parameters which differed with respect to the brand of equipment used, imaging software, running time (20 to 48 h), and pulsing conditions. In conclusion, it appears that the standardization of PFGE depends on controlling a variety of experimental intricacies, as is the case with other bacterial typing procedures.

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