Rapid Identification and Susceptibility Testing of Gram-Negative Bacilli from Blood Cultures Using the Vitek 2 System

Providing rapid results for blood culture isolates is a critical function of clinical microbiology laboratories. This study evaluated the accuracy and turnaround time for identification and susceptibility testing of Gram-negative bacilli inoculated directly from positive blood cultures into the Vitekr 2 system. Direct inoculation was compared to conventional methods; which included biochemical tests; commercial identification systems and disc diffusion susceptibility testing. Two hundred and ninety-one of 327 isolates (89) were correctly identified to at least genus level by the direct Vitekr method. Susceptibility test results were compared for 3;925 organism antibiotic combinations. The overall rate of categorical agreement of direct and conventional antimicrobial susceptibility testing was 92with less than 3very major and major errors combined. The mean turnaround time for identification and susceptibility testing was 7.5 hours (SD 3.0 hours) compared to a mean of 32.3 hours (SD 14.7 hours) for the conventional method. These results suggest that direct inoculation of the Vitekr 2 system from blood cultures provides accurate; reliable identification and antimicrobial susceptibility results for the majority of commonly occurring Gram-negative pathogens; while the significantly reduced turnaround time should benefit patients and permit earlier rationalisation of antibiotic therapy; with a reduction in the use of broad spectrum antibiotics. A suggested protocol for routine use is included

Superior Detection of Pathogens in Synovial Fluid by the Bactec 9240 Peds Plus/F System Compared to the Conventional Agar-based Culture Method

To improve culture yield in cases of possible septic arthritis; we compared culture of joint fluid aspirates on conventional agar-based media to culture in Bactec 9240 Peds/Plus F blood culture bottles with and without the addition of fastidious organism supplement (FOS). Over a period of 21 months; we analysed 123 synovial fluid samples and isolated 20 pathogens. The Bactec methods proved superior by yielding more pathogens than the conventional culture method (p=0.074). However; this method also yielded more contaminants within the first three days of incubation (p=0.027). All contaminants detected after three days of incubation were the result of overgrowth on conventional method agar plates. The Bactec methods provided clinicians with a positive pathogen result one day earlier than the conventional counterpart (p=0.001). Four isolates of Neisseria gonorrhoeae were only cultured with the Bactec method. No significant benefit was demonstrated by supplementing blood culture bottles with FOS. We recommend that whenever infection by fastidious organisms is suspected; synovial fluid aspirates should be cultured using automated blood culture systems to increase the culture yield and to decrease the time to detection

Azadirachta indica (Neem) Seed Extracts : A Supplement for Culture Medium for Growth of Aspergillus niger

The effectiveness of Neem seed extracts (Azadirachta indica A. Juss) was tested against Aspergillus niger isolated from soil to determine whether the neem seed extracts will inhibit or enhance the growth of Aspergillus niger. Three different concentrations of neem seed extracts were prepared 10; 20 and 50. The results showed that the neem seed extracts enhanced the growth of Aspergillus niger from 24 hours of incorporation up to 120 hours. The growth enhancement was also found to increase with concentration of the seed extracts

Problematique de la culture du BK au 6eme mois du traitement antituberculeux standard dans les tuberculoses pulmonaires bacilliferes au CAT d' Adjame

Notre etude de type transversale avait pour objectif principal de determiner le taux de positivite de la culture chez des patients tuberculeux pulmonaires bacilliferes declares gueris apres le traitement antituberculeux de 1ere ligne. Pour cela; nous avons realise la culture des expectorations chez 307 patients recrutes au C.A.T. d'Adjame. Le taux de positivite de la culture est de 1;3 pour cent soit 4 sur 307 patients. L'analyse des resultats concernant ces 4 patients a permis de relever: 1) AU PLAN EPIDEMIOLOGIQUE: un age compris entre 16 et 35 ans; sans predominance d'un sexe ; le niveau d'instruction est inferieur ou egal au primaire dans 75 pour cent des cas contre 25 pour cent dans le superieur ; 4 sur 4 des patients appartiennent aux categories socioprofessionnelles des sans emploi ou ouvriers et manouvres. AU PLAN DES ANTECEDENTS ET LA SEROLOGIE VIH: le zona est retrouve chez 1 patient sur 4 ; la serologie VIH est positive dans 25 pour cent des cas et negative dans 25 pour cent des cas. Par contre 50 pour cent des patients ont refuse le test. AU PLAN CLINIQUE: l'amaigrissement persiste chez 50 pour cent des patients et l'examen physique revele la presence de rales crepitants chez 100 pour cent des patients. AU PLAN PARA CLINIQUE: 50 pour cent des patients ont ete diagnostiques avec une bacilloscopie moyennement positive et 50 pour cent une bacilloscopie fortement positive ; 3 sur 4 des patients presentent en fin de traitement; des images radiologiques de sequelles contre l'amelioration radiologique dans 114 des cas ; les 4 cultures positives ont permis d'isoler 2 mycobacteries tuberculeuses et 2 mycobacteries atypiques dont une est pigmentee et a croissance rapide. On note 0 pour cent de MDR. AU PLAN THERAPEUTIQUE: 100 pour cent des patients ont declare avoir regulierement suivi le traitement avec une posologie normale. Au terme de ce travail; aucun des parametres etudies n'ayant permis d'expliquer valablement ces echecs; il serait souhaitable de poursuivre cette etude afin de tirer des conclusions significatives