Characterization of the enzyme aac(3)-Id in a clinical isolate of Salmonella enterica serovar Haifa causing traveler's diarrhea

Travel-Related Antimicrobial Resistance: A Systematic Review

There is increasing evidence that human movement facilitates the global spread of resistant bacteria and antimicrobial resistance (AMR) genes. We systematically reviewed the literature on the impact of travel on the dissemination of AMR. We searched the databases Medline, EMBASE and SCOPUS from database inception until the end of June 2019. Of the 3052 titles identified, 2253 articles passed the initial screening, of which 238 met the inclusion criteria. The studies covered 30,060 drug-resistant isolates from 26 identified bacterial species. Most were enteric, accounting for 65% of the identified species and 92% of all documented isolates. High-income countries were more likely to be recipient nations for AMR originating from middle- and low-income countries. The most common origin of travellers with resistant bacteria was Asia, covering 36% of the total isolates. Beta-lactams and quinolones were the most documented drug-resistant organisms, accounting for 35% and 31% of the overall drug resistance, respectively. Medical tourism was twice as likely to be associated with multidrug-resistant organisms than general travel. International travel is a vehicle for the transmission of antimicrobial resistance globally. Health systems should identify recent travellers to ensure that adequate precautions are taken.

Non-Typhoidal Salmonella in poultry meat and diarrhoeic patients: prevalence, antibiogram, virulotyping, molecular detection and sequencing of class I integrons in multidrug resistant strains

Background

The worldwide increase of food-borne infections with antibiotic resistant pathogens constitutes a major public health problem. Therefore, this study aimed to determine the prevalence, antibiogram, virulence genes profiles and integron characteristics of non-typhoidal Salmonella spp. isolated from poultry meat and diarrhoeic patients in Egypt.

Methods

A total of 150 samples comprising (100 poultry meat and 50 diarrhoeic patients’ stool) were examined for the presence of Salmonella spp. using culture methods followed by biochemical and serological identification of the isolates. All Salmonella strains were tested for their susceptibility to the antibiotics using disk diffusion method and screened for the presence of virulence genes and class I integrons using PCR.

Results

The overall prevalence of Salmonella spp. in poultry meat samples was 10 % compared to 4 % in diarrhoeic patients. All the isolates were serologically identified into Salmonella Typhimurium (seven isolates), S. Derby, S. Kiel, S. Rubislaw (one isolate, each) and untypable strains (two isolates). Antibiotic susceptibility testing showed a higher resistance of the total isolates to erythromycin and tetracycline (100 %, each), followed by amoxicillin-clavulanic acid (91.7 %), trimethoprim-sulfamethoxazole (83.3 %), streptomycin, nalidixic acid, ampicillin-sulbactam (75 %, each), gentamycin, ampicillin (66.7 %, each), chloramphenicol (58.3 %), ciprofloxacin (25 %) and ceftriaxone (16.7 %). Virulence genes profiles revealed the presence of sopB gene in five Salmonella strains isolated from poultry meat (n = 3) and humans (n = 2). Moreover, pefA was only identified in three isolates from poultry meat. On the other hand, S. Kiel and S. Typhimurium (one isolate, each) were harboring hilA and stn genes, respectively. Class 1 integrons were detected in all Salmonella spp. with variable amplicon sizes ranged from 650–3000 bp. Sequencing of these amplicons revealed the presence of gene cassettes harboring aac(3)-Id, aadA2, aadA4, aadA7, sat, dfrA15, lnuF and estX resistance genes. Nucleotide sequence analysis showed point mutations in the aac(3)-Id of S. Derby, aadA2, estX-sat genes of S. Typhimurium. Meanwhile, frame shift mutation was observed in aadA7 genes of S. Typhimurium.

Conclusions

Increasing rate of antimicrobial resistance and class 1 integrons among multidrug resistant Salmonella spp. has prompted calls for the reduction of antimicrobial use in livestock to prevent future emergence of resistance.

Antimicrobial activity and clinical effectiveness of sisomicin: an evaluation of the literature (1995-2011)

The authors sought to evaluate whether sisomicin has a place in the current therapeutic armamentarium. PubMed and Scopus databases were systematically searched. Ten cohort studies and 11 case reports and case series were included evaluating, in total, 383 Gram-positive and 83 Gram-negative isolates. Sisomicin was active in vitro against 41% of Enterococcus spp., 97% of Staphylococcus spp. and was the most active in vitro (74%) aminoglycoside against Stenotrophomonas maltophilia isolates in one study. Regarding clinical effectiveness, sisomicin topical cream was effective in all 290 patients with pyoderma in one study, while the intravenous formulation of sisomicin was effective as prophylaxis for the development of postoperative pneumonia in 91% of lung surgery patients in another. In conclusion, sisomicin may be useful against certain pathogens; however, clinical data are scarce. Further studies are needed and may shed additional light in this area.