[Use of the Streptotest kit for identification of enterococci isolated from human clinical material]. / Pouzití soupravy STREPTOtest pro identifikaci enterokoku izolovaných z humánního klinického materiálu.

Enterococci are part of the common microflora of man and are isolated in large numbers also from the environment. Recently their presence in clinical material is increasing and they have become an important causal agent of nosocomial infections. From human clinical material (urine, vaginal smears, wounds) a total of 164 strains of enterococci was isolated. Identification of these isolates by means of the commercial STREPTOtest kit was not very successful (71.3%). The use of several supplementary tests and evaluation by the TNW programme improved successful identification (98.8%). The dominating species in clinical material was E. faecalis (94.5%), the second most frequent isolated species was E. faecium (3%). To achieve better identification of enterococci the authors recommend to supplement the kit by further tests (acidification of arabinose, ribose and pyruvate assimilation).

[Use of semi-solid Diasalm medium for isolation of Salmonella enteritidis]. / Pouzití polotuhého Diasalm média k izolaci Salmonella enteritidis.

The Diagnostic Semi-solid Salmonella Agar (DIASALM) was compared with two commercial semi-solid Rappaport-Vasiliadis media (MSRV by Oxoid and SRVA, basis by HiMedia) using 52 strains of Salmonella and 10 strains of interfering Gram-negative bacteria. The diagnostic potency for salmonellae was higher in DIASALM than in MSRV or SRVA. Unlike the Rappaport-Vasiliadis media, DIASALM contains a diagnostic system consisting of lactose, saccharose and bromocresol purple, allowing the differentiation of salmonellae from non-pathogenic Gram-negative sugar-fermenting bacteria (Tab. I). The semi-solid media were supplemented with 0.0015% nitrofurantoine to recover specifically Salmonella enteritidis. Eighty percent of strains of the latter serovar were resistant to this chemotherapeutic agent, while all the other serovars were sensitive to it. The use of discs soaked with the monovalent Salmonella antiserum H:g,m increased the recovery rate in 95 percent of S. enteritidis strains. Compared with the cultures from peptone water, the diameters of the migration zones formed by the positive cultures grown in M-broth were larger by 3 to 5 mm. Pure cultures of salmonellae were isolated in 98% of cases from the borders of the migration zones when mixed cultures of salmonellae (a S. enteritidis isolate from a patient, density 10(3) to 1 or 2 cells per drop) and Citrobacter koseri or Edwardsiella tarda, or Proteus mirabilis, or Psedomonas aeruginosa (densities > or = 10(3) cells per drop) were inoculated onto DIASALM (Tab III).

[Use of the NEFERMtest apparatus for identification of gram-negative non-fermenting rods occurring in clinical material]. / Vyuzití soupravy NEFERMtest pro identifikaci gramnegativních nefermentujících tycek vyskytujících se v klinickém materiálu.

The new identification system NEFERMtest (fy Lachema, Brno) was evaluated. The identification efficacy of two systems, Index (fy Lachema) and computer programme (Czech Collection of Microorganisms, Brno) was compared. A total of 222 bacterial strains including 41 species occurring in clinical material were tested. The Index identified correctly to the species level 38 strains (27.1%) of the reference strains and 32.9% of 82 clinical isolates. The identification efficacy of the computer programme TNW was 48.6% for the reference strains, 95.1% for the strains obtained from clinical specimens.

Mercuric reductase in environmental gram-positive bacteria sensitive to mercury.

According to existing data, mercury resistance operons (mer operons) are in general thought to be rare in bacteria, other than those from mercury-contaminated sites. We have found that a high proportion of strains in environmental isolates of Gram-positive bacteria express mercuric reductase (MerA protein): the majority of these strains are apparently sensitive to mercury. The expression of MerA was also inducible in all cases. These results imply the presence of phenotypically cryptic mer resistance operons, with both the merA (mercuric reductase) and merR (regulatory) genes still present, but the possible absence of the transport function required to complete the resistance mechanism. This indicates that mer operons or parts thereof are more widely spread in nature than is suggested by the frequency of mercury-resistant bacteria.

[Identification of enteric bacteria using the ENTEROtest 1 and 2 and the ENTERO-Rapid systems]. / Identifikace strevních baktérií systémy ENTEROtest 1 a 2 a ENTERO-Rapid.

The identification efficacy of two systems, ENTEROtest 1 & 2 and ENTERO-Rapid (fy. Lachema a. c., Brno), was compared. A total 123 well known strains of enteric bacteria were tested. The ENTEROtest 1 & 2 system correctly identified 87.0% tested strains to the species level, the ENTERO-Rapid system correctly identified 76.4% of these strains.

[Use of the Streptotest for identification of enterococci and viridans-type streptococci]. / Vyuzití soupravy STREPTOtest pro identifikaci enterokoku a viridujících streptokoku.

The new identification system STREPTOtest (fy. Lachema, Brno) was evaluated. A total 118 well-known strains of genus Enterococcus, Streptococcus, Aerococcus, Stomatococcus and Gemella were tested. The STREPTOtest system rapidly and reliably distinguished genus Enterococcus from genus Streptococcus. This method identified correctly to the species level 65.9% of enterococci strains and 52.5% of streptococci strains. The STREPTOtest was used for identification of A. viridans and S. mucilaginosus and it was possible to separate these strains from similar ones. A new differentiation chart for identification of all 13 recently described enterococcal species was proposed.