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A polyphasic taxonomic study using morphological, biochemical, chemotaxonomic and molecular methods was performed on three strains of a Gram-stain positive, non-sporeforming, motile aerobic rod-shaped bacterium resistant to tylosin and tetracycline isolated from a swine-manure storage pit. On the basis of 16S rRNA gene sequence analyses, it was confirmed that these isolates are highly related to each other and form a hitherto unknown lineage within the Planococcaceae. In particular, pairwise analysis of the 16S rRNA gene sequence demonstrated that the novel organism is closely related to members of the genus Sporosarcina (92.8-94.5 %), Pyschrobacillus (93.5-93.9 %) and Paenisporosarcina (93.3-94.5 %). The predominant fatty acids were found to consist of iso-C15:0 and iso-C17:1 ω10c and the G+C mol% was determined to be 41.8. Based on biochemical, chemotaxonomic, and phylogenetic evidence, it is proposed that these novel strains be classified as a novel genus and species, Savagea faecisuis gen nov., sp. nov. The type strain is Con12(T) (=CCUG 63563(T) = NRRL B-59945(T) = NBRC 109956(T)).

A novel bacterial strain, DCY86(T) (=KCTC 42053(T) = JCM 19890(T)) was isolated from soil of a ginseng field in Yeoncheon province (38°04'00″N 126°57'00″E), Republic of Korea using a serial dilution method. Strain DCY86(T) was observed to be Gram-stain negative, strictly aerobic, to grow optimally at 25-30 °C, at pH 7-7.5 and on tryptic soya agar medium. The cells were found to be sensitive to ceftazidine and tetracycline. Based on 16S rRNA gene sequence comparisons, strain DCY86(T) was found to be most closely related to Cupriavidus basilensis LMG 18990(T) (98.48 %), Cupriavidus numazensis LMG 26411(T) (98.34 %), Cupriavidus pinatabonesis KCTC 22125(T) (98.34 %) and Cupriavidus laharis KCTC 22126(T) (98.00 %). The G+C content was determined to be 64.23 mol %. The only isoprenoid quinone detected in strain DCY86(T) was ubiquinone Q-8. The major polar lipids were identified as diphosphatidylglycerol, phosphtidylethanolamine, phosphatidylglycerol, unidentified aminophosphoglycolipids and unidentified phospholipids. The major fatty acids were identified as C16:0 summed feature 3 (C16:1 ω7c/ω6c and/or iso-C15 : 0 2-OH) and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). These data support the affiliation of strain DCY86(T) to the genus Cupriavidus. Strain DCY86(T) was also found to be able to solubilize phosphate and produce siderophores. The results of physiological and biochemical tests enabled strain DCY86(T) to be differentiated genotypically and phenotypically from the recognized species of the genus Cupriaividus. Therefore, the novel isolate can be considered to represent a novel species, for which the name Cupriavidus yeoncheonense sp. nov. is proposed here. The type strain is DCY86(T) (=KCTC 42053(T) = JCM 19890(T)).

Lactic acid bacteria (LAB) resistant to erythromycin were isolated from different food samples on selective media. The isolates were identified as Enterococcus durans, Enterococcus faecium, Enterococcus lactis, Enterococcus casseliflavus, Lactobacillus salivarius, Lactobacillus reuteri, Lactobacillus plantarum, Lactobacillus fermentum, Pediococcus pentosaceus and Leuconostoc mesenteroides. Of the total 60 isolates, 88 % harbored the ermB gene. The efflux gene msrA was identified in E. faecium, E. durans, E. lactis, E. casseliflavus, P. pentosaceus and L. fermentum. Further analysis of the msrA gene by sequencing suggested its homology to msrC. Resistance to tetracycline due to the genes tetM, tetW, tetO, tetK and tetL, alone or in combination, were identified in Lactobacillus species. The tetracycline efflux genes tetK and tetL occurred in P. pentosaceus and Enterococcus species. Since it appeared that LAB had acquired these genes, fermented foods may be a source of antibiotic resistance.

A total of 74 Streptococcus thermophilus isolates collected between 1948 and 2005 from different environments were investigated to assess erythromycin, clindamycin, streptomycin, gentamicin, tetracycline and ampicillin susceptibility by means of microdilution, Etest and disk diffusion methods. For this purpose a new S. thermophilus Susceptibility test Medium (SSM) was developed. This medium allowed a better identification of strains with atypical tetracycline resistance. The recipe is a mixed formulation of Iso-Sensitest medium (90% v/v) and M17 medium (10% v/v) supplemented with lactose (0.5% w/v). The overall agreement of the techniques was good with exception of tetracycline, for which Etest provided lower MICs than the microdilution method. Most strains were susceptible to all the antibiotics tested while a few erythromycin, tetracycline and streptomycin resistant strains were detected.

The resistance of Salmonellae to drugs has been studied in the Netherlands since 1958. In 1972, 1973, and 1974 respectively, 14241, 13086, and 22927 strains were tested for resistance to ampicillin, chloramphenicol, kanamycin and tetracycline. From 1973 all strains were also tested for resistance to trimethoprim. In the period covered, the yearly incidence of resistance to at least one of the above drugs ranged from 39.2% to 45.6% of all strains obtained from various sources (humans, animals, animal products, sewage, etc.). A new finding in the period 1972 to 1974 was that many multiply resistant strains emerged in S. typhimurium and in S. dublin isolated from calves and cattle. In 1974, 64.4% of all strains of S. typhimurium from these animals appeared to be resistant to ampicillin, tetracycline, chloramphenicol and kanamycin, and 25.5% of those of S. dublin were found to be resistant to chloramphenicol and tetracycline. Of all strains of Salmonellae examined in 1973 and 1974 respectively, 0.15% and 0.22% were resistant to trimethoprim, the main component of the twin-drug cotrimoxazol. Of the 142 strains of S. typhi isolated in 1972 to 1974 two were resistant to tetracycline only, and one was resistant to all four antibiotics. The others had a normal susceptibility pattern.

Klebsiella aerogenes harbouring the plasmid pBR322 was grown in continuous culture at various growth rates under glucose, phosphate or ammonia limitation. With tetracycline in the medium, the maximum culture beta-lactamase activity was found at the higher growth rates. When tetracycline was absent, loss of resistance to the drug occurred. Concomitant with the occurrence of drug-sensitive cells, the culture beta-lactamase activity decreased. At the higher growth rates the enzyme activity decreased at a slightly higher rate than did the resistance to tetracycline. From this it was concluded that the beta-lactamase activity per mg cellular dry weight of the drug-resistant fraction of the population was still decreasing during the appearance of drug-sensitive cells. At the higher growth rates, this decrease was independent of the nutrient that was growth-limiting.

Isolates of group D streptococci from above and below a sewer outfall and a series of clinical isolates have been speciated to sub-species level. From below the sewer outfall, Streptococcus faecalis var. faecalis predominates whereas above the outfall, S. faecium var. casseliflavus predominates. S. faecalis var. faecalis, S. faecalis var. liquefaciens and S. faecalis var. zymogenes were the predominant sub-species in the clinical isolates where S. faecium var. casseliflavus was virtually absent. S. faecalis var. liquefaciens and S. faecalis var. zymogenes were uncommon in the environmental isolates. S. faecium and S. durans were more abundant in the environmental than in the clinical isolates. The use of group D streptococci as indicators of faecal pollution would seem more suited to higher, rather than lower, levels of pollution. A statistically significant increase in resistance to antibiotics (ampicillin, penicillin, streptomycin, gentamicin, erythromycin and tetracycline) was seen in isolates from below the outfall compared with those from above and a further significant increase was seen in the clinical isolates compared with the former. Resistance to tetracycline was most common and ampicillin was the only antibiotic tested to which no resistance was detected. Multiple antibiotic resistance was rare in the environmental isolates. Even in moderately polluted water, there is not a large pool of antibiotic resistance.

A novel approach to determine the tetracycline susceptibility of Chlamydia trachomatis directly from specimens without cell culture propagation and adaptation has been explored. Out of a total of 1290 genital specimens from a sexually transmitted disease clinic, 211 (16.4%) were positive for C. trachomatis. A tetracycline concentration of 0.032 microgram/ml completely inhibited the appearance of inclusions in all of the 211 positive specimens. Of the positive specimens, 120 (56.9%) and 18 (8.5%) respectively showed the presence of 1 to 9 and 100 or more inclusions per microtiter well in antibiotic free medium. Other antibiotics are being tested in the same manner.

Of 153 clinical isolates of shigellae examined, 64.7% belonged to Shigella flexneri, 18.9% to Sh. sonnei, 11.8% to Sh. boydii and 4.6% to Sh. dysenteriae. Part of these isolates were resistant to sulfamethoxazole and streptomycin (88.2% each), ampicillin (66.7%), tetracycline (63.4%) and co-trimoxazole (43.1%), with levels of resistance (MIC50 and MIC90) being invariably high. Resistance to three or more drugs (multidrug resistance) was seen in 77.8% of the isolates. All the 25 strains examined for transfer of resistance contained R-plasmids, both autotransferable and non-autotransferable (mobilized by transfer factor X). The frequency of transfer of different r-determinants varied from 2.7 X 10(-8) to 1.4 X 10(-3).

In Staphylococcus aureus transduction of different tetracycline and chloramphenicol plasmids with a group I/III modification was possible to group I and III strains. Group II strains, containing a restriction endonuclease, had a restriction both for the phage and the plasmids: two restriction-deficient group II strains were good acceptors for these plasmids.

Populations of a Escherichia coli K 12 strain, containing the vector plasmid pBR 322, were grown in chemostat culture under glucose- and phosphate-limited conditions. Resistance to tetracycline and ampicillin were lost after prolonged cultivation, resulting in the production of apparent plasmid-free populations which were more competitive than the original population. This competitiveness between plasmid-free and plasmid-containing populations was greatest in environments where the nutrient restriction was severe. Also during sequential subcultivation in batch cultures loss of plasmid was observed.

From 1975-1980, about 130 000 Salmonella strains isolated from various sources were tested for resistance to ampicillin, chloramphenicol, kanamycin, tetracycline and trimethoprim. Following the ban on incorporation of tetracycline in animal feeds for nutritive purposes, tetracycline resistance in S. typhimurium and S. panama strains of porcine origin dropped from about 90% in 1974 for both species, to about 34% and 1%, respectively, 1980. The incidence of resistance in human strains concurrently decreased from about 80% in 1974 to 25% and 1%, respectively, in 1980. The build-up of multiple resistance in bovine S. dublin and S. typhimurium strains, already started in 1973-74, has continued. Recently, phage type 193 S. typhimurium strains have become predominant and they are invariable resistant to ampicillin, chloramphenicol, tetracycline, kanamycin, neomycin, streptomycin, sulphonamide and trimethoprim. Up to now, type 193 strains were hardly encountered in human patients, but the number of human isolates is slowly increasing. A fairly large number of multiply resistant strains belonging to S. oranienburg, S. schwarzengrund, S. typhimurium and, recently, S. krefeld have been isolated from adoptive children from the Far East.