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. 2006 Sep;44(9):3346-51.
doi: 10.1128/JCM.02631-05.

As a bacterial culture medium, citrated sheep blood agar is a practical alternative to citrated human blood agar in laboratories of developing countries

F M Russell  1 , S S N Biribo, G Selvaraj, F Oppedisano, S Warren, A Seduadua, E K Mulholland, J R Carapetis
Affiliations

As a bacterial culture medium, citrated sheep blood agar is a practical alternative to citrated human blood agar in laboratories of developing countries

F M Russell et al. J Clin Microbiol. 2006 Sep.

Abstract

Human blood agar (HuBA) is widely used in developing countries for the isolation of bacteria from clinical specimens. This study compared citrated sheep blood agar (CSBA) and HuBA with defibrinated horse blood agar and defibrinated sheep blood agar (DSBA) for the isolation and antibiotic susceptibility testing of reference and clinical strains of Streptococcus pneumoniae, Streptococcus pyogenes, and Staphylococcus aureus. Reference and clinical strains of all organisms were diluted in brain heart infusion and a clinical specimen of cerebrospinal fluid and cultured on all agars. Viable counts, colony morphology, and colony size were recorded. Susceptibility testing for S. pneumoniae and S. pyogenes was performed on defibrinated sheep blood Mueller-Hinton agar, citrated sheep blood Mueller-Hinton agar (CSB MHA), and human blood Mueller-Hinton agar plates. For all organisms, the colony numbers were similar on all agars. Substantially smaller colony sizes and absent or minimal hemolysis were noted on HuBA for all organisms. Antibiotic susceptibility results for S. pneumoniae were similar for the two sheep blood agars; however, larger zone sizes were displayed on HuBA, and quality control for the reference strain failed on HuBA. For S. pyogenes, larger zone sizes were demonstrated on HuBA and CSBA than on DSBA. Poor hemolysis made interpretation of the zone sizes difficult on HuBA. CSBA is an acceptable alternative for the isolation of these organisms. The characteristic morphology is not evident, and hemolysis is poor on HuBA; and so HuBA is not recommended for use for the isolation or the susceptibility testing of any of these organisms. CSB MHA may be suitable for use for the susceptibility testing of S. pneumoniae.

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Figures

FIG. 1.
FIG. 1.
Growth of S. pneumoniae ATCC 6305 on the four different blood agars at a dilution of 1 × 101 CFU/ml.
FIG. 2.
FIG. 2.
Growth of S. aureus ATCC 25923 on the four different blood agars at a dilution of 1 × 102 CFU/ml.
FIG. 3.
FIG. 3.
Growth of Streptococcus pyogenes ATCC 19615 on the four different blood agars at a dilution of 1 × 102 CFU/ml.
See this image and copyright information in PMC

References

    1. Anand, C. R., H. Gordon, H. Shaw, K. Fonseca, and M. Olsen. 2000. Pig and goat blood as substitutes for sheep blood in blood-supplemented agar media. J. Clin. Microbiol. 38:591-594. - PMC - PubMed
    1. Centers for Disease Control and Prevention. 1998. Laboratory methods for the diagnosis of meningitis caused by Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae. Centers for Disease Control and Prevention, Atlanta, Ga.
    1. Gratten, M., D. Battistutta, P. Torzillo, J. Dixon, and K. Manning. 1994. Comparison of goat and horse blood as culture medium supplements for isolation and identification of Haemophilus influenzae and Streptococcus pneumoniae for upper respiratory tract secretions. J. Clin. Microbiol. 32:2871-2872. - PMC - PubMed
    1. Hoppe, J. E., and M. Schlagenhauf. 1989. Comparison of three kinds of blood and two incubation atmospheres for cultivation of Bordetella pertussis on charcoal agar. J. Clin. Microbiol. 27:2115-2117. - PMC - PubMed
    1. Johnson, D. R., E. L. Kaplan, J. Sramek, R. Bicova, J. Havlicek, H. Havilickova, J. Moliova, and P. Kriz. 1996. Laboratory diagnosis of group A streptococcal infections. World Health Organization, Geneva, Switzerland.

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