Genetic basis of tetracycline resistance in food-borne isolates of Listeria innocua.

Eleven of 12 tetracycline-resistant Listeria innocua strains, isolated from chicken or turkey frankfurters and mozzarella cheese, were shown to carry DNA sequences which hybridized with the Tet M probe; of these, two strains also hybridized with Tet K. The remaining strain hybridized with the Tet K probe only. The Tet M determinant appeared to be located on the chromosome; in one case, it was transferable by conjugation to recipients Listeria monocytogenes, Listeria ivanovii, and Enterococcus faecalis.

Keratomycosis with an unusual etiology (Rhodotorula glutinis): a case report.

A case of deep keratomycosis with isolation of Rhodotorula glutinis is discussed. Keratoplasty, done immediately, prevented panophthalmitis and cured the patient. The etiology and pathogenesis of fungal keratitis is examined.

Streptococcus mutans: classification in bacteriocin-types.

A sample of S. mutans bacteriocins was studied to obtain a useful outline of strain typing since their synthesis has proved stable and not under plasmidial control. The inhibiting effectiveness against 9 oral streptococci and the sensitivity of mutacins produced by 49 S.

Restriction endonuclease analysis of chromosomal DNA from Listeria monocytogenes strains.

Restriction endonuclease analysis of chromosomal DNA was applied to thirteen Listeria monocytogenes strains alongside the more conventional typing methods of serotyping and phage typing. The organisms were isolated from cases of sporadic listeriosis (nine strains); from an occasional nosocomial cluster (two strains); and from food samples (two strains). Purified DNAs were digested with EcoRI restriction endonuclease, and restriction fragments separated by electrophoresis.

Carbamimidothioic acid phenylmethyl ester salts and their N,N'-tetramethyl derivatives as possible antimicrobial agents.

A series of carbamimidothioic acid phenylmethyl ester salts and their N,N'-tetramethyl derivatives were synthesized, many of which exert an interesting inhibiting action on Gram-positive and Gram-negative bacteria and also on fungi. This activity is noteworthy in view of the large number of strains antagonized; the (3,4,5-trichlorophenyl) methyl ester chloride of carbamimidothioic acid appeared to be the best term of the series. The possible influence on this activity of decomposition kinetics to the corresponding mercapto-derivatives was investigated and compared with that of a series of N,N'-tetramethyl derivatives of previously studied carbamimidothioic acid phenyl ester salts.

Production of bacteriocin-like substances by human oral streptococci.

A sample of human streptococci (mainly Streptococcus mutans species) from dental plaques was examined in order to evaluate the production frequency and activity spectrum of bacteriocin-like substances (mutacins). 89% of the 55 Streptococcus mutans strains produced substances with a wide spectrum of antibacterial activity. The bacteriocins produced showed a marked inhibitory activity against Gram-positive bacteria.

In vitro antibacterial activity of enoxacin, a new pyridonecarboxylic acid.

The antibacterial activity of enoxacin was determined against 1015 strains of Gram-positive and Gram-negative bacteria, mainly freshly isolated from clinical specimens. The minimum inhibitory concentrations (MIC 50-75-90) were determined in comparison to three commonly used antibiotics: ampicillin, cefotaxime and gentamicin. Enoxacin has shown a broad spectrum of action and antibacterial activity in general higher that than of three currently available antibiotics.

Synthesis and antimicrobial activity of monoalkylcarbamic and thiocarbamic esters of 3-mercapto-1,2,4-benzothiadiazine-1,1-dioxide and of its Bz-derivatives.

A new series of monoalkylcarbamic esters of 3-mercapto-1,2,4-benzothiadiazine-1,1-dioxide (I) and of its 6-chloro- and 5,7-dichloroderivatives [compounds (II leads to XVI)] and a series of monoalkylthiocarbamic esters of (I) [compounds (XVII leads to XIX)] were synthesized and evaluated in vitro for antimicrobial activity. All the substances studied have been found to possess an inhibiting action on one or more strains of mycetes of the genus Candida and on some strains of Gram-positive bacteria belonging to the genus Staphylococcus. Moreover, some compounds have shown a bacteriostatic effect on a strain belonging to the genus Streptococcus.

[Current trends in the use of combined serum and vaccine in tetanus prevention].

There is evidence that when plain tetanus toxoid is given at the same time as antitoxin, the response to the toxoid is inhibited. Good responses can be obtained when absorbed tetanus toxoid is used with non-human antitoxin, but there is evidence of an interval (10-15 days) between the end of passive immunization and the beginning of the active one. Using absorbed tetanus toxoid at the same time as human antitoxin there is complete absence of interference.

[The incidence and variation of transferable antibiotic-resistance in Salmonella strains isolated in Modena in the years 1975-1977 (author's transl)].

The antibiotic-resistance of 450 strains of Salmonella isolated by the Microbiology Unit of the hospital of Modena during the years 1975-1977 was examined. During the study, the following antibiotics were assayed: ampicillin, kanamycine, tetracycline, chloramphenicol, streptomycin, sulfonamides, trimethoprim, tobramycin, gentamicin and nalidixic acid. The transfer capacity of antibiotic-resistance was measured by the double conjugation of E.

[Antimicrobial activity of derivatives of 1,2,4-benzothiadiazine-1,1-dioxide. VIII].

The antimicrobial activity of a series of fluoro derivatives of benzothiadiazine and sulfonamides was studied. The compounds tested can be grouped as: a) 3-alkylmercapto derivatives of 6-trifluoromethyl-1,2,4-benzothiadiazine-1,1-dioxide (III leads to VI); the 3-mercapto precursor (VII) and the related 3-picolinic salt (VIII); b) 3-trifluoromethyl derivatives of 1,2,4-benzothiadiazine-1,1-dioxide and of its benzene substituted derivatives (IX leads to XVI); c) trifluoroacetylaminobenzenesulfonamides (XVII leads to XXV). Two of the 3-alkylmercapto compounds [(V) and (VI)] showed marked inhibitory activity against some strains of Staphylococcus, Streptococcus and Diplococcus.

[Antimicrobial effect of derivatives of 1,2,4-benzothiadiazin-1,1-dioxide. VII].

Series of alkyl derivatives of the following have been prepared: 5,7-dichloro- [compounds (II leads to V)], 6-methyl- [compounds (VI leads to IX)] and 6-methoxy-3-mercapto-1,2,4-benzothiadiazine-1,1-dioxide [compounds (X leads to XIII)]. The products were tested for antimicrobial activity. Studies were also made of the corresponding 3-mercapto precursors (XIV, XV, XVI) and the relative 3-picolinium salts (XVII, XVIII, XIX) and also of the 3-picolinium salts of 6-chloro-, 7-chloro- and 6,7-dichloro-3-mercapto-1,2,4-benzothiadiazine-1,1-dioxide (XX, XXI, XXII).