Polyresistance of salmonell serovov, isolated from Poultry and from poultry products

Salmonellosis  remains  an  important  problem  not  only  in  the  Russian  Federation,  but throughout the world, both in veterinary medicine and in medicine. Poultry is the most affected by salmonella. Most often, S. Enteritidis, S. Typhimurium, S. Infantis, S. Gallinarum-pullorum are  isolated  from  poultry  and  poultry  products.  It  is  these  salmonella  serovars  that  cause outbreaks of foodborne diseases in humans. For the prevention and treatment of salmonellosis, antibiotics  of  various  groups  are  used: β-lactams,  fluoroquinolones,  cephalosporins,  etc. Unfortunately,  at  present,  most  of  the  latest  generation  antibiotics  are  ineffective.  However, many Salmonella isolates have been found to have multiple drug resistance (MDR). MDR strains began to actively displace those that were resistant to only one or two antibiotics. Antibioticresistant  bacterial  strains  are  transmitted  to  humans  through  the  use  of  insufficiently  heattreated poultry meat, through contact with raw poultry products, as well as through eggs and egg  products.  45  strains  of  Salmonella  isolated  from  sick  poultry,  as  well  as  carcasses  and poultry meat products were studied. Cultivation, study of biochemical, serological properties and  virulence  were  carried  out  according  to  standard  methods.  Sensitivity  to  35  antibiotics was  determined  using  the  disk  diffusion  method.  In  the  study  of  antibiotic  resistance  of Salmonella serovars S. Enteritidis, S. Typhimurium, S. Infantis, it was found that they all had multidrug resistance, and most of the strains were resistant to 11–18 drugs out of 35 used. №t a  single  strain  was  found  that  was  resistant  to  only  1–7  antibiotics.  All  strains  were  multiresistant, with 100% of Salmonella resistant to clindamycin, tylosin, oleandomycin, rifampicin, ampicillin, and penicillin. More than 80% of the studied strains were resistant to erythromycin, doxycycline, tetracycline. Aminoglycosides (kanamycin, neomycin, streptomycin, gentamicin, amikacin),  amphenicols  (chloramphenicol)  suppressed  the  growth  of  60–90%  of  Salmonella strains. The most effective were fluoroquinolones of the 2nd and 3rd generation, capable of inhibiting the growth of 80-100% of isolates, especially ciprofloxacin and enrofloxacin. These drugs are backup antibiotics. However, isolates resistant to ciprofloxacin and enrofloxacin have been found, which is alarming. 4th generation fluoroquinolones have been shown to be less effective, especially for S. infantis. Perhaps this is due to the use of fluoroquinolones among poultry  at  large  poultry  enterprises  for  the  prevention  of  salmonellosis.  Only  about  30%  of isolates  were  resistant  to  first-generation  cephalosporins  (cefazolin,  cephalexin).  Among the  3rd  generation  cephalosporins,  the  most  effective  were  cephaperazone  and  especially ceftriaxone, to which no Salmonella isolate was resistant. 47% of S. Typhimurium is resistant to cefepime (4th generation cephalosporin), while sensitivity to other serovariants is up to 67%.