Resistance of Salmonellae Isolated in 1962 to Chlortetracycline

Among 652 salmonellae examined, Salmonella typhimurium displayed a much higher incidence of resistance to chlortetracycline than did other serotypes. Among S. typhimurium cultures from man, the incidence of resistance (38%) increased markedly over that of cultures isolated 3 years previously (13.9%), whereas a similar increase was not noted among cultures from fowls. Resistance among cultures from animals other than fowls (72.5%) was due largely to the high incidence of resistance among cultures from bovine sources (93.7%).     

Antibiotic resistance in the bacteria of a remote upland river catchment

The incidence of antibiotic resistance was determined in a total of 183 heterotrophic bacteria of non-faecal origin isolated from the catchment of a remote upland stream. Some 40% were sensitive to each of the eight antibiotics tested while more than 35% were resistant to at least two compounds. Three isolates each carried seven resistance determinants. Unsuccessful attempts were made, using two curing techniques, to demonstrate that resistance was plasmid-borne. The high incidence of antibiotic resistance, particularly amongst pseudomonads, in an environment virtually free from anthropogenic influence is surprising, and has implications for the assessment of the spread of antibiotic resistance amongst populations of environmental bacteria.     

Infectious Drug Resistance Among Clinically Isolated Escherichia coli

Of 398 strains of clinically isolated Escherichia coli from three Birmingham, Alabama, hospitals, 38% were found to be resistant to one or more drugs tested. Fifty-seven per cent of the resistant strains transferred all or a part of their resistance pattern to sensitive cells during mixed cultivation. Of the 152 resistant strains, 29.1% were singly resistant, and 70.5% were resistant to more than one drug. Of the multiply resistant strains, 61% transferred all or a part of their pattern. Strains isolated from Veterans Hospital patients demonstrated higher percentages of resistance than strains isolated from Children's Hospital patients. An extremely low incidence of infective drug resistance was noted among E. coli isolated from the stools of healthy hospital employees.     

Spread of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) in hospitals in Taipei, Taiwan in 2005, and comparison of its drug resistance with previous hospital-acquired MRSA

Panton-Valentine leucocidin (PVL)-positive methicillin-resistant Staphylococcus aureus (PVL+ MRSA) is an emerging pathogen in the community worldwide. The incidence of PVL+ MRSA in Taipei, Taiwan was 23.3% for hospital MRSA. PVL+ MRSA was isolated from both outpatients and inpatients. Some PVL+ (mecA+) strains (36.8%) showed low MIC values (相似文献   

Incidence of antibiotic resistance and sex pheromone response among enterococci isolated from clinical human samples and from municipal waste water

The incidence of resistance to various antibiotics as well as the capacity to elicit aggregation response to sex pheromones have been investigated in strains of Enterococcus faecalis isolated from clinical and municipal waste waters (MWW). While clinical isolates showed a high incidence of antibiotic resistance (87%) and sex pheromone response (33%), these traits appeared with a much lower frequency in MWW isolates (12% and 4% respectively). The simultaneous incidence of both traits was of 52% and 0% for clinical and MWW isolates, respectively. The capacity to elicit a positive pheromone response as well as antibiotic resistance traits seemed to be strongly correlated with the presence of gelatinase activity among clinical isolates. Among MWW isolates, only sex pheromone response seemed to correlate with the presence of gelatinase activity.     

Drug resistance and pathogenicity of S. aureus isolated from patients

Over the period 1983-1985, investigators from the Institute of Hygiene and Epidemiology, Prague, and the Central Research Institute of Epidemiology, USSR Ministry of Public Health, Moscow, carried out a joint study of drug resistance in S. aureus strains in relation to their enterotoxigenic properties and phage group specificity. Altogether 277 strains were explored which had been isolated at random from the clinical material from infant and adult inpatients. Most of the isolated strains featured multiple resistance to antibiotics: PNC (77.9%), CMP (52.7%), TET (21.6%), ERY (17.6%) and LIN (11.9%). The strains isolated from infants were most frequently resistant to TET and ERY. No correlation was found between the incidence of antimicrobial drugs resistance and toxigenic properties of the isolated strains.     

Antibiotic resistance of native and faecal bacteria isolated from rivers, reservoirs and sewage treatment facilities in Victoria, south-eastern Australia

The incidence of resistance to ampicillin, chloramphenicol, kanamycin, nalidixic acid, neomycin and streptomycin was significantly greater (P < 0.001) in native heterotrophic bacteria than in Escherichia coli isolated from a range of sites along the Yarra River in south-eastern Australia. There was no significant difference in the incidence of resistance between native and faecal bacteria to tetracycline. Both groups were almost totally resistant to penicillin. Multivariate analyses indicated little clear spatial pattern in the incidence of resistance in native bacteria from upstream vs downstream sites along the Yarra River. In contrast, E. coli isolated from upstream (rural) sites tended to have a lower incidence of resistance than isolates from downstream (urban) sites. These findings have implications for the use of antibiotic resistance as a bacteriological water quality parameter.     

Drug Resistance of Enteric Bacteria XIII. Distribution of R Factors in Escherichia coli Strains Isolated from Livestock

Escherichia coli strains isolated from 151 swine and 108 fowl, which were kept at the Animal Health Center, Maebashi, Japan, were surveyed for drug resistance and distribution of R factors. All of the swine and 38% of the fowl excreted E. coli strains resistant to tetracycline, chloramphenicol, streptomycin, and sulfanilamide, or certain combinations thereof. Among 278 resistant cultures isolated from swine, 13% were found to be resistant to one antibiotic, whereas 87% were resistant to more than one antibiotic. Among these resistant strains, 40% carried R factors which were transferable by the usual conjugal process. The resistance patterns of these R factors included 36% which were singly resistant and 64% which were multiply resistant. Among 54 resistant cultures isolated from fowl, 24% were singly resistant and 76% were multiply resistant. Of the resistant strains from fowl, 22% carried R factors. The resistance patterns of R factors included 50% of the singly resistant type and 50% which were multiply resistant. In spite of feeding with dairy products containing only tetracycline, a high incidence of multiple resistance was observed in the E. coli strains and the R factors isolated from these animals.     

Fimbriation, surface hydrophobicity and serum resistance in uropathogenic strains of Escherichia coli

Abstract A total of 80 Escherichia coli strains were examined for expression of P-fimbriae, mannose-sensitive haemagglutination (MSHA) and mannose-resistant haemagglutination (MRHA) of human group A erythrocytes and guinea pig erthrocytes, cell surface hydrophobicity and resistance to serum bactericidal activity. Isolates were obtained from urine of children and adults, either with acute pyelonephritis ( n = 15 and n = 12) or lower urinary tract infection (UTI) ( n = 30 and n = 23, respectively). Results obtained showed that, in E. coli strains isolated both from children and adults with lower UTI, significant differences were not found concerning the incidence of P-fimbriae, cell surface hydrophobicity and serum resistance. In pyelonephritogenic E. coli isolated from children and adults, the incidence of P-fimbriae and cell surface hydrophobicity was associated more frequently with the former (87% vs. 42% and 100% vs. 67%, P < 0.05), while serum resistance was associated with the latter (47% vs. 67%, P < 0.05).     

Short Communication: Antibiotic resistance among faecal coliform bacteria isolated from wastewater before and after treatment by an experimental sand filter

During the functioning period of a sand filter, 254 and 234 faecal-coliform strains were isolated from raw wastewater and reclaimed effluent, respectively. When tested for their susceptibility to ampicillin, kanamycin, chloramphenicol, streptomycin and tetracycline, 53% of the strains from the raw sewage and 84% of those isolated from the effluent were resistant to at least one antibiotic. The high incidence of drug resistance in the effluent was connected with a high proportion of Klebsiella pneumoniae, Enterobacter cloacae and Citrobacter freundii.     

Antibiotic resistant bacteria in Windermere and two remote upland tarns in the English Lake District

The incidence of antibiotic resistance was determined in over 2000 bacteria which were divided into the following groups: faecal streptococci, coliforms (excluding Escherichia coli), E. coli, Pseudomonas spp. and aquatic bacteria (i.e. bacteria predominant in the lake water which were excluded from the previous four categories). The isolates were obtained from the water of Windermere (English Lake District) and from a sewage effluent which entered the lake. With the exception of the faecal streptococci, the incidence of antibiotic resistance was higher in the bacteria isolated from the lake water than in those from the effluent, and ranked according to groups Pseudomonas spp. greater than E. coli greater than aquatic bacteria greater than coliforms greater than faecal streptococci. The highest incidence of multiple resistance was found among the pseudomonads. When corrected for the relative size of each population the pool of antibiotic resistance in the aquatic bacteria was by far the largest. The incidence of antibiotic resistance in aquatic bacteria isolated from Windermere was, however, lower than in those isolated from two remote upland tarns. This finding may have been due to differences in the species composition of the three sites except that the same results were obtained when only fluorescent pseudomonads were tested. The upland tarns were not totally isolated from man and other animals but did not receive any sewage or other effluents and therefore the results were surprising. Possible explanations include a lack of susceptibility in aquatic bacteria and increased resistance associated with growth in nutrient poor environments.     

Antibiotic resistant bacteria in Windermere and two remote upland tarns in the English Lake District

The incidence of antibiotic resistance was determined in over 2000 bacteria which were divided into the following groups: faecal streptococci, coliforms (excluding Escherichia coli ), E. coli, Pseudomonas spp. and aquatic bacteria (i.e. bacteria predominant in the lake water which were excluded from the previous four categories). The isolates were obtained from the water of Windermere (English Lake District) and from a sewage effluent which entered the lake. With the exception of the faecal streptococci, the incidence of antibiotic resistance was higher in the bacteria isolated from the lake water than in those from the effluent, and ranked according to groups Pseudomonas spp. > E. coli > aquatic bacteria > coliforms > faecal streptococci. The highest incidence of multiple resistance was found among the pseudomonads. When corrected for the relative size of each population the pool of antibiotic resistance in the aquatic bacteria was by far the largest. The incidence of antibiotic resistance in aquatic bacteria isolated from Windermere was, however, lower than in those isolated from two remote upland tarns. This finding may have been due to differences in the species composition of the three sites except that the same results were obtained when only fluorescent pseudomonads were tested. The upland tarns were not totally isolated from man and other animals but did not receive any sewage or other effluents and therefore the results were surprising. Possible explanations include a lack of susceptibility in aquatic bacteria and increased resistance associated with growth in nutrient poor environments.     

Antibiotic resistance of Salmonella strains isolated from children living in the wastewater-spreading field of Marrakesh city (Morocco)

A total of 813 Salmonella strains isolated from raw wastewater and stool specimens of inpatient children, living in the wastewater-spreading field of Marrakesh city, were examined for their susceptibility to 15 antimicrobial agents. All the isolates were susceptible to cefotaxime, and almost of them showed susceptibility to gentamicin (99.88%), trimethoprim-sulphamethoxazole (98.04%), nalidixic acid (98.04%), kanamycin (97.30%), trimethoprim (97.18%), and chloramphenicol (96.07%). The highest levels of antibiotic resistance were obtained for cephalothin (29.27%), amoxicillin (26.44%), sulphamethoxazole (26.07%), and ampicillin (25.21%). The strains from the serogroup B showed the highest antibiotic resistance frequencies. The percentage of polyresistant strains (36.09%) was significantly higher than that of monoresistant isolates (15.49%). The incidence of drug resistance in Salmonella isolates from stools was significantly higher than in those isolated from wastewater.     

Olaquindox resistance in the coliform flora of pigs and their environment: an ecological study

Faecal samples were taken weekly from a chosen pen on each of four commercial pig farms, two of which used olaquindox as a feed additive. Coliform bacteria were isolated from the samples and the incidence and level of resistance to olaquindox and to four therapeutic antibiotics determined. The coliforms isolated were biotyped to follow the emergence of drug-resistant sub-populations. The results showed that the coliform flora was complex and that a turnover of biotypes was associated with changes in the occupancy of the pen and, possibly, diet. This turnover led to large fluctuations in both incidence and level of resistance to olaquindox and the antibiotics. Olaquindox resistance was not specifically linked with resistance to any therapeutic antibiotic, and the possible origin of olaquindox-resistant strains is discussed in relation to the biotypes.     

Olaquindox resistance in the coliform flora of pigs and their environment: an ecological study

Faecal samples were taken weekly from a chosen pen on each of four commercial pig farms, two of which used olaquindox as a feed additive. Coliform bacteria were isolated from the samples and the incidence and level of resistance to olaquindox and to four therapeutic antibiotics determined. The coliforms isolated were biotyped to follow the emergence of drug-resistant sub-populations. The results showed that the coliform flora was complex and that a turnover of biotypes was associated with changes in the occupancy of the pen and, possibly, diet. This turnover led to large fluctuations in both incidence and level of resistance to olaquindox and the antibiotics. Olaquindox resistance was not specifically linked with resistance to any therapeutic antibiotic, and the possible origin of olaquindox-resistant strains is discussed in relation to the biotypes.     

Bacterial Plasmids in Antarctic Natural Microbial Assemblages

Samples of psychrophilic and psychrotrophic bacteria were collected from sea ice, seawater, sediments, and benthic or ice-associated animals in McMurdo Sound, Antarctica. A total of 155 strains were isolated and tested for the presence of plasmids by DNA agarose gel electrophoresis. Thirty-one percent of the isolates carried at least one kind of plasmid. Bacterial isolates taken from sediments showed the highest plasmid incidence (42%), and isolates from seawater showed the lowest plasmid incidence (20%). Plasmids were significantly more frequent in the strains which had been first isolated from low-nutrient media (46%) than in the strains which had been isolated from high-nutrient media (25%). Multiple forms of plasmids were observed in two-thirds of the plasmid-carrying strains. A majority of the plasmids detected were estimated to have a mass of 10 megadaltons or less. Among 48 plasmid-carrying strains, 7 showed antibiotic resistance. It is concluded that bacterial plasmids are ubiquitous in natural microbial assemblages of the pristine marine ecosystem of Antarctica.     

R plasmids among Gram-negative bacteria with multiple drug resistance isolated in a general hospital.

The incidence of conjugative R plasmids in multiple drug-resistant strains of gram-negative bacteria isolated in 1973 from patients in a 700-bed general hospital in Tokyo and some properties of the R plasmids isolated are described. Conjugative R plasmids were found in 52 of the 96 strains (54%), from which 74 R plasmids were demonstrated. It is remarkable that the isolation frequency of R plasmids mediating quadruple- or five-drug resistance was rather low, and the complete pattern of multiple resistance of the original isolates was only rarely transferred by conjugation. These results revealed the existing state of the distribution of R plasmids among hospital strains with multiple drug-resistance.     

Antibiotic and heavy metal resistance in Gram-negative bacteria isolated from the Seyhan Dam Lake and Seyhan River in Turkey

This study aimed to determine the pattern of antibiotic and heavy metal resistance in Gram-negative bacteria isolated from five different sites in the Seyhan Dam Lake and Seyhan River in Adana, Turkey. The susceptibility of 268 isolates to 16 different antibiotics and five heavy metals was investigated by agar diffusion and dilution methods, respectively. The most common species isolated from the samples were Aeromonas hydrophila (17.5 %), Aeromonas caviae (8.9 %) and Citrobacter freundii (8.9 %). There was a high incidence of resistance to ampicillin (80.2 %), streptomycin (71.6 %) and cefazolin (60.4 %). Multiple antibiotic resistance indices ranged from 0.2 to 0.81, suggesting exposure to antibiotic contamination. The isolates showed tolerance to different concentrations of heavy metals. These results indicate that antibiotic and heavy metal resistance among the Seyhan Dam Lake and Seyhan River bacteria may pose a risk to the fish population and public health. At the same time, the finding in the aquatic environments of different combinations of resistance genes suggests their involvement in the spread of multidrug-resistant strains.     

孕产妇产后感染病原菌的构成及耐药性分析

目的了解孕产妇产后感染病原菌的分布及耐药现状,为临床抗感染治疗提供依据。方法采用法国生物梅里埃VITEK-2全自动细菌鉴定分析仪进行鉴定和药敏试验,采用WHONET5.6软件进行数据统计分析。结果 2012年1月至2015年12月我院产科病房孕产妇共60 229例,产后感染336例,感染主要部位为宫腔、切口、血液和尿液。主要病原菌依次为大肠埃希菌、粪肠球菌、B型链球菌和金黄色葡萄球菌。大肠埃希菌对头孢他啶、头孢吡肟、妥布霉素、阿米卡星、头孢替坦、哌拉西林/他唑巴坦、头孢哌酮/舒巴坦、亚胺培南耐药率均15.00%;粪肠球菌和无乳链球菌对氨苄西林、青霉素耐药率为0.00%,耐甲氧西林金黄色葡萄球菌(MRSA)耐药率高达19.05%。结论我院产科病房感染主要部位为宫腔(43.18%),减少剖宫产率可以降低产后感染发生率,感染的主要病原菌为大肠埃希菌和粪肠球菌(63.23%),在预防用药的选择上应选择对大肠埃希菌和粪肠球菌均有效的抗生素以减少产后感染的发生率,同时了解孕产妇产后感染病原菌的构成和耐药性,有助于临床更快速有效地治疗产后感染。     

Drug Resistance and R Plasmids in Escherichia coli Strains Isolated from Imported Pet Birds

Drug resistance in Escherichia coli strains isolated from pet birds (mynahs, macaws, finches, common bengals, parrots, and flamingos) imported into Japan from 10 foreign countries in 1977 and 1978 was investigated. Of the 309 strains isolated from 127 pet birds in the Animal Quarantine Service, 232 (75.1%) were drug resistant. Furthermore, strains resistant to oxytetracycline hydrochloride, dihydrostreptomycin, and sulfadimethoxine were relatively common. Resistance patterns varied from single to sextuple resistance, and 148 (63.8%) of the resistant strains had conjugative R plasmids. These results suggest that the high incidence of drug resistance and R plasmids in E. coli strains isolated from these pet birds may be a reflection of the prophylactic use of antibiotics for the prevention of diseases which increasingly occur with importation of the birds. Furthermore, the results suggest that the birds may be potential reservoirs of drug-resistant E. coli for families who raise and have intimate contact with such birds.