ABSTRACT
The benzethonium chloride resistance of 341 strains of Pseudomonas aeruginosa isolated from Jikei University Hospital was determined. The distribution pattern of the susceptibility to benzethonium chloride clearly revealed two peaks, and the resistance was differentiated by 1000 micrograms/ml (0.1%) of benzethonium chloride. The frequency of resistance to benzethonium chloride was 51.6%. Furthermore, the frequencies of resistance to SM, TC, CP, KM, GM, PIP, Hg, Cd, As and chlorhexidine were 42.5, 15.8, 41.3, 29.6, 14.0, 8.2, 88.3, 97.9, 97.1, and 74.5%, respectively.
Subject(s)
Benzethonium/pharmacology , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/drug effects , Quaternary Ammonium Compounds/pharmacology , Anti-Bacterial Agents/pharmacology , Chlorhexidine/pharmacology , Drug Resistance, Microbial , Humans , Japan , Metals/pharmacology , Pseudomonas aeruginosa/isolation & purificationABSTRACT
Clinical isolates of Citrobacter (277 strains) were studied for the resistance to four metals and four drugs. The distribution patterns of their susceptibility to Hg, Cd and As clearly revealed two peaks, but only a single peak of resistance to Pb. The frequencies of resistance to Hg, Cd, As, SM, TC, CP and KM were 31.8, 94.2, 57.8, 51.3, 44.8, 35.7 and 28.9%, respectively. And we selected 88 mercury resistant strains, and they were tested for their ability to transfer the resistance to the mercury and drug sensitive recipients of E. coli K12-ML1410-Nx and E. coli JE17-Rif. Among 88 strains of Hg resistant Citrobacter, 80 R plasmids with Hg resistance could be demonstrated. It should be noted that transferable R plasmids with Hg resistance were demonstrated in 91% of the Hg-resistant isolates. Furthermore, we tested the volatilization of mercury by strains containing these mercury resistance plasmids, by using radioactive 203Hg2+. All of these isolates of Citrobacter have volatilization activity of Hg2+. Also, all of these volatilization activity is inducible.
Subject(s)
Citrobacter/genetics , Enterobacteriaceae Infections/microbiology , Hydrogen/metabolism , Metals/pharmacology , R Factors , Anti-Bacterial Agents/pharmacology , Arsenates/pharmacology , Cadmium/pharmacology , Cadmium Chloride , Citrobacter/drug effects , Citrobacter/metabolism , Humans , Japan , Mercuric Chloride/pharmacology , VolatilizationABSTRACT
The chlorhexidine resistance of 317 strains of Pseudomonas aeruginosa isolated from hospital patients was determined. The distribution pattern of their susceptibility to chlorhexidine clearly revealed two peaks, and the frequency of resistance to chlorhexidine was 84.2%.
Subject(s)
Chlorhexidine/pharmacology , Pseudomonas aeruginosa/drug effects , Anti-Bacterial Agents/pharmacology , Drug Resistance, Microbial , Humans , Mercury/pharmacologyABSTRACT
Clinical isolates of Escherichia coli (148 strains) were studied for their resistance to chlorhexidine, six antibiotics and three metals. The distribution pattern of their susceptibility to chlorhexidine clearly revealed two peaks, and the resistance was differentiated by 5 micrograms/ml of chlorhexidine. Resistance to chlorhexidine was found in 12.8% of the isolates. The frequencies of resistance to SM, TC, CP, KM, CER, GM, Hg, Cd and As were 43.2, 36.4, 18.9, 25.0, 16.2, 4.1, 35.1, 91.2 and 47.2%, respectively. The frequency of chlorhexidine resistance was lower than that of drug and metal resistance except in the case of GM resistance. Furthermore, all of these chlorhexidine-resistant strains were multiple-drug-resistant also multiple-metal-resistant.
Subject(s)
Chlorhexidine/pharmacology , Escherichia coli Infections/microbiology , Escherichia coli/drug effects , Anti-Bacterial Agents/pharmacology , Arsenic/pharmacology , Cadmium/pharmacology , Drug Resistance, Microbial , Mercury/pharmacologyABSTRACT
Clinical isolates of K. pneumoniae (746 isolates) were studied for the resistance to four metals and four drugs. The distribution patterns of their susceptibility to Hg, Cd and As clearly revealed two peaks, but only a single peak of resistance to Pb. It can be seen that resistance was demonstrable in media containing the following concentrations of the metals (micrograms/ml): HgCl2, 10; CdCl2, 400; and Na2HAsO4, 400. In K. pneumoniae, the frequency fo resistance to these concentrations of Hg, Cd and As were 65,8%, 98,3% and 83,8%, respectively. On the other hand, the frequency to antibiotic resistance of K. pneumoniae were 68,1% of SM, 51,2% of TC, 49,7% of CP and 36,7% of KM. Furthermore, many isolates (99,6%) were metal-resistant. Most of these metal-reisitant strains were multiple-metal-resistant and also multiple-drug-resistance. And about 30% of total isolates were metal-resistant but drug-sensitive, whereas the frequency of the metal-sensitive and drug-resistant strains was 0%.
Subject(s)
Anti-Bacterial Agents/pharmacology , Klebsiella pneumoniae/drug effects , Metals/pharmacology , Arsenic/pharmacology , Cadmium/pharmacology , Chloramphenicol/pharmacology , Drug Resistance, Microbial , Kanamycin/pharmacology , Lead/pharmacology , Mercury/pharmacology , Streptomycin/pharmacology , Tetracycline/pharmacologyABSTRACT
The mercury and antibiotic resistance of 338 strains of Escherichia coli isolated from hospital patients was determined. Resistance to mercury was found in 58.6% of the isolates. The frequencies of resistance to streptomycin (Sm), tetracycline (Tc), chloramphenicol (Cm), kanamycin (Kan), cephaloridine (Cer), and gentamicin (Gm) were 66.3, 60.3, 56.5, 42.9, 32.1, and 1.5%, respectively. Among the above, 198 mercury- and antibiotic-resistant isolates were selected and tested for their ability to transfer the resistance to susceptible strains of E. coli K-12 and Klebsiella pneumoniae JK5. R plasmids carrying mercury resistance were demonstrated in 89.9% of the mercury-resistant strains of E. coli. Furthermore, R(Hg,Sm,Tc,Cm) plasmids were demonstrated most frequently, followed by R(Hg,Sm,Tc,Cm,Kan), R(Hg,Cm,Kan), and R(Hg,Sm,Tc,Cm,Kan,Cer) plasmids.
Subject(s)
Drug Resistance, Microbial , Escherichia coli Infections/microbiology , Escherichia coli/drug effects , Mercury/pharmacology , R Factors , Anti-Bacterial Agents/pharmacology , HumansABSTRACT
The mercury and antibiotic resistance of 155 clinical isolates of Klebsiella pneumoniae (K. pneumoniae) was determined. Resistance to mercury tested was found in 64.5% of the total isolates. The frequencies of resistance to SM, TC, CP, KM and GM were 65.8%, 49.0%, 48.4%, 37.4% and 3.9%, respectively. And we selected 94 mercury and drug resistant strains, and they were tested for their ability to transfer the resistance to the mercury and drug sensitive recipients of E. coli K12 ML 1410-Nx and E. coli JE 17-Rif. Among 94 strains of Hg resistant K. pneumoniae, 86 R plasmids with Hg resistance could be demonstrated. It should be noted that transferable R plasmids with Hg resistance were demonstrated in 92% of the Hg-resistant isolates. Furthermore, R (Hg; SM, TC, CP, KM) plasmids were isolated most frequently, followed by R (Hg; SM, TC, CP), R (Hg; SM, KM), and R (Hg; SM, TC) plasmids.
Subject(s)
Conjugation, Genetic , Drug Resistance, Microbial , Klebsiella pneumoniae/drug effects , Mercury/pharmacology , R Factors , Anti-Bacterial Agents , Humans , Klebsiella Infections/genetics , Klebsiella pneumoniae/isolation & purificationABSTRACT
Of the 787 isolates, 99.8% were metal resistant, with most (99.5%) showing multiple resistance. Fifty-three percent of the isolates were both metal and drug resistant, whereas only 19% were metal resistant and drug sensitive.
