ABSTRACT
Salmonella spp. continues to figure prominently in world epidemiological registries as one of the leading causes of bacterial foodborne disease. We characterised 43 Brazilian lineages of Salmonella Typhimurium (ST) strains, characterized drug resistance patterns, tested copper (II) complex as control options, and proposed effective antimicrobial measures. The minimum inhibitory concentration was evaluated for seven antimicrobials, isolated and combined with the copper (II) complex [Cu(4-FH)(phen)(ClO4)2] (4-FH = 4-fluorophenoxyacetic acid hydrazide and phen = 1,10-phenanthroline), known as DRI-12, in planktonic and sessile ST. In parallel, 42 resistance genes were screened (PCR/microarray). All strains were multidrug resistant (MDR). Resistance to carbapenems and polymyxins (86 and 88%, respectively) have drawn attention to the emergence of the problem in Brazil, and resistance is observed also to CIP and CFT (42 and 67%, respectively), the drugs of choice in treatment. Resistance to beta-lactams was associated with the genes blaTEM/blaCTX-M in 39% of the strains. Lower concentrations of DRI-12 (62.7 mg/L, or 100 µM) controlled planktonic and sessile ST in relation to AMP/SUL/TET and AMP/SUL/TET/COL, respectively. The synergistic effect provided by DRI-12 was significant for COL/CFT and COL/AMP in planktonic and sessile ST, respectively, and represents promising alternatives for the control of MDR ST.
ABSTRACT
Carbapenemase-producing Enterobacteriaceae (CPE) represent an increasing public health issue and the early detection of colonization by CPE can help the implementation of infection control measures among inpatients. In this study, BD MAX Check-Direct CPE screen, with two different Master Mixes (BDMix and CPMix), using the automatic BD MAX(™) instrument, was evaluated for the detection of blaKPC, blaOXA-48, blaVIM and blaNDM genes, in comparison to selective broth enrichment and direct culture from rectal swabs. Among a total of 557 rectal swabs samples, 29 (5.2%) tested positive for CPE (23 for blaKPC, 5 for blaVIM and one for blaOXA-48). The sensitivity, specificity, positive and negative likelihood ratios values were 93.1%, 97.3%, 34.5 and 0.07, for BMix, and 100%, 97.1 %, 34.5 and 0 for CPMix, respectively. Five samples were positive with molecular methods only. The turn-around time was reduced from 18-24 hours (direct culture), or 48 h (broth enrichment) to only 3 h.
Subject(s)
Bacterial Proteins/analysis , Bacteriological Techniques/methods , Enterobacteriaceae Infections/diagnosis , Enterobacteriaceae/enzymology , Molecular Diagnostic Techniques/methods , Real-Time Polymerase Chain Reaction/methods , beta-Lactamases/analysis , Automation, Laboratory/methods , Bacterial Proteins/genetics , Endemic Diseases , Enterobacteriaceae/genetics , Enterobacteriaceae/isolation & purification , Enterobacteriaceae Infections/epidemiology , Enterobacteriaceae Infections/microbiology , Humans , Predictive Value of Tests , Rectum/microbiology , Sensitivity and Specificity , beta-Lactamases/geneticsABSTRACT
Nowadays most animal feed products imported into Europe have a GMO (genetically modified organism) label. This means that they contain European Union (EU)-authorized GMOs. For enforcement of these labeling requirements, it is necessary, with the rising number of EU-authorized GMOs, to perform an increasing number of analyses. In addition to this, it is necessary to test products for the potential presence of EU-unauthorized GMOs. Analysis for EU-authorized and -unauthorized GMOs in animal feed has thus become laborious and expensive. Initial screening steps may reduce the number of GMO identification methods that need to be applied, but with the increasing diversity also screening with GMO elements has become more complex. For the present study, the application of an informative detailed 24-element screening and subsequent identification strategy was applied in 50 animal feed samples. Almost all feed samples were labeled as containing GMO-derived materials. The main goal of the study was therefore to investigate if a detailed screening strategy would reduce the number of subsequent identification analyses. An additional goal was to test the samples in this way for the potential presence of EU-unauthorized GMOs. Finally, to test the robustness of the approach, eight of the samples were tested in a concise interlaboratory study. No significant differences were found between the results of the two laboratories.
