Antibiotic susceptibility of different lactic acid bacteria strains

Abstract

Five lactic acid bacteria (LAB) strains belonging to species Lactobacillus acidophilus, Lactobacillus helveticus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus delbrueckii subsp. lactis and Streptococcus thermophilus were tested for their susceptibility to 27 antibiotics. The minimum inhibitory concentrations of each antimicrobial were determined using a microdilution test. Among the strains a high susceptibility was detected for most of the cell-wall synthesis inhibitors (penicillins, cefoxitin and vancomycin) and resistance toward inhibitors of DNA synthesis (trimethoprim/sulfonamides and fluoroquinolones). Generally, the Lactobacillus strains were inhibited by antibiotics such as chloramphenicol, erythromycin and tetracycline at breakpoint levels lower or equal to the levels defined by the European Food Safety Authority. Despite the very similar profile of S. thermophilus LC201 to lactobacilli, the detection of resistance toward erythromycin necessitates the performance of additional tests in order to prove the absence of transferable resistance genes.

In vitro Assessment of Antibiotic Resistance Pattern among Lactobacillus Strains Isolated from Goat Milk

“…Resistance towards quinolones may be explained with the nucleotide substitutions (gyrA and/or gyrB) within the quinolone-resistance determining region of DNA gyrase subunits (Baines and Wilcox, 2015), or due to mutation in topoisomerase IV (Hummel et al, 2007). (Karapetkov et al, 2011). In agreement to above publish reports, we have also noted down the high resistance pattern against aminoglycosides (streptomycin, tobramycin), with an exception of gentamicin, against which both resistance and intermediate susceptibility was recorded.…”

Protective Effect of Probiotics Strains in Ruminants

“…When the quantification was made through the selection at least five colonies from fecal sample during seven weeks of 1 to 5 sheep the results were 24, 26, 29, 30 and 29 in the group II and 20,15,19,18,16 in the group III (Table.2 and Table.3). The results show that there was no isolating of STEC non-O157 from sheep before the inoculation of bacteria inoculated.…”

“…Some lactic bacteria could present antibiotic resistance and these bacteria used for food is considered a major danger since this resistance could be transferred to pathogenic bacteria. The probiotics strains used in our study were tested to susceptibility to 27 antibiotics and verified that generally the Lactobacillus strains were inhibited to all antibiotics tested (Karapetkov et al, 2011).…”

Key Roles of Human Polymorphonuclear Cells and Ciprofloxacin in Lactobacillus Species Infection Control

“…In particular, CIP has a broad antibacterial spectrum, with bactericidal activity toward Gram-positive and Gram-negative aerobes (5,19); it accumulates inside the PMNs and remains active, leading to a significant reduction in the number of intracellular bacteria, such as Aggregatibacter actinomycetemcomitans (formerly Actinobacillus actinomycetemcomitans) (20).…”

“…Lactobacilli have the potential to act as reservoirs of antibiotic resistance genes similar to those found in human pathogens, with the risk of transferring these genes to many pathogenic bacteria (5,9,10). Fortunately, drug resistance does not always correlate with therapeutic clinical failure: the host defense mechanisms play a key role during infection in preventing the triggering and spread of bacterial infection (11).…”