Api 20 strep

Honey samples were screened for their antibacterial activity against 11 bacterial strains isolated from the urine of pregnant women suffering from urinary infection at Ibn Rochd Hospital, Annaba, situated in east of Algeria. These strains are as follows: Escherichia coli, Enterobacter aerogenes, Klebsiellaoxytoca, Klebsiella pneumoniae, Proteus mirabilis, Proteus vulgaris, Citrobacter koseri, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus and Staphylococcus saprophyticus. All tested strains were identified by conventional methods of microbiology (Gram staining, oxidase and catalase test, analytical profile index (API) 20E, API 20NE, API STAPH and API 20 STREP) (Biomerieux, Paris, France).
An inoculum of each strain was prepared, and the turbidity of the suspension was adjusted to achieve 0.5 McFarland (equivalent to that of 1.5 × 10⁸ colony-forming units (CFU)/mL) with the absorbance range of 0.08 to 0.1 by UV-Vis spectrophotometer at wave length of 620 nm.
All bacterial strains were subjected to antibiotic sensitivity tests by the Kirby Bauer’s disc diffusion method according to the Clinical and Laboratory Standards Institute [22 ] using Mueller Hinton agar medium (Biomerieux, Paris, France). The tested strains were selected because they are resistant to antibiotics used in the treatment of urinary infection during pregnancy.

Confirmed decarboxylase-positive strains were identified based on Gram stain and catalase and citochromooxidase activity [35 ]. Further identification to the species level was carried out by a variety of biochemical tests using API 20-E, API 20-Strep, API-Staph and API 50-CH strips (BioMérieux, Marcy l’Etoile, France).

Using cotton wool moistened with alcoholic iodine, the area of the skin surrounding the lesions was cleaned thoroughly. After appropriate cleaning, the ulcer specimens were obtained by rubbing sterile saline solution over the edge of the ulcerated lesions and then transferring the swabs to Muller Hinton broth and nutrient broth medium. After a 24 h incubation at 37 °C, one loop of the samples was streaked on each of Muller Hinton Agar, Nutrient agar, M-Enterococcus agar, Ogwa agar, and Sabouraud agar. Gram staining was used to determine the species of bacteria.
API 20 E, API 20 NE, API 20 STREP, and API 20C (BioMérieux, Marcy l’Etoile, France) were used for the identification of different isolates. The strips were inoculated, incubated at 37 °C for 24 h or 48 h, and analyzed according to the manufacturer’s instructions for each kit. The reactions were recorded, and the identifications were determined using a computer program (API Lab Plus software version 3.2.2 (BioMérieux, Marcy l’Etoile, France)).

Cases were identified retrospectively by searching the Laboratory Information Management System (LIMS) database (Clinisys WinPath Enterprise). S. pneumoniae was confirmed on culture of blood or fluid from affected joint(s) at a central laboratory, using standard microbiological techniques outlines in UK standards for microbiology investigations (UK-SMI) combined with API®-20 Strep (BioMérieux, UK) and/or MALDI-TOF (matrix-assisted laser desorption/ionisation/time of flight) mass spectrometer (Bruker, UK). Confirmed cases were linked with the Public Health England (PHE) national reference laboratory to obtain serotype data for each case [19 (link)]. Serotyping was performed by phenotypic methods including the Quellung reaction until September 2017, which was replaced by whole genome sequencing thereafter [20 (link)]. A positive UAT (BinaxNOW®, Alere, UK) was also considered confirmative of pneumococcal infection. Confirmation of pneumococcal infection in addition to a diagnosis of septic arthritis by the treating physician was considered diagnostic of pneumococcal septic arthritis.
S. pneumoniae serotypes contained within each vaccination are listed in Supplementary data 2.

Thirty-nine colonies were randomly isolated from KAA agar plates and 258 from MRS agar plates of the spoiled and unspoiled sausages (total 297 isolates) containing 10 to 50 colonies and streaked onto the same new media.
After purification, the colonies were subjected to Gram staining and to a catalase test and then stored at −20 °C in MRS broth containing 30% (v/v) glycerol until molecular identification and characterisation. Gram-positive streptococci and catalase-negative colonies were identified by API 20 Strep according to the manufacturer’s method (BioMerieux Marcy-l’Étoile, France). Gram-positive rod, catalase-negative colonies (LAB) were identified by the method reported in [40 (link)].

A total of 66 S. suis serotype 2 (SS2) isolates were included in this study. Sixty-two human SS2 were isolated from 43 and 19 patients at Maharaj Nakorn Chiang Mai Hospital and Lamphun Provincial Hospital, respectively. To isolate S. suis from pigs, a total of 150 submaxillary lymph nodes of healthy pigs that were bought from two retail markets in the municipal area of Chiang Mai province between November and December 2002 were studied. From each homogenized sample, S. suis was isolated on NNCC agar (sodium azide, nalidixic acid, colistin-crystal violet agar) “as described by Kataoka et al. [9 (link)]” and selective blood agar (sheep blood agar + SR126E, oxoid). All α-hemolytic gram-positive cocci were screened first with standard biochemical tests and confirmed with an API 20 Strep (bioMérieux). S. suis serotype 2 was identified by the coagglutination test with antiserotype 1 (negative reaction) and 2 (positive reaction) antibodies “as discussed by Gottschalk et al. [6 (link)].” P1/7 strain, a reference strain of serotype 2, which was isolated from a diseased pig with the mrp⁺ epf⁺ sly⁺ genotype, was used as a positive control. For negative control, we used beta-hemolytic streptococci and distilled water.