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D S Hodge

Publications and source records attributed to D S Hodge.

6 recordsLinked to original sources
PubMed1991

Selective medium for isolation of Arcanobacterium haemolyticum and Streptococcus pyogenes.

Sheep blood agar using tryptic soy agar base and containing 3.5% sodium chloride was found to facilitate isolation of Arcanobacterium haemolyticum and improve isolation of Voges-Proskauer negative group A (Streptococcus pyogenes) and group C and G beta-haemolytic streptococci. Commensal oropharyngeal flora such as viridans streptococci, Neisseria species, non-haemolytic streptococci and beta-haemolytic streptococci not belonging to groups A, B, C or G were significantly inhibited.

Agar↗
PubMed1990

Rapid biochemical test to identify verocytotoxin-positive strains of Escherichia coli serotype O157.

Fluorogenic procedures were used with the substrate 4-methylumbelliferyl-beta-D-glucuronide (MUG) to identify Escherichia coli. Most strains produced beta-glucuronidase and, thus, were MUG positive. A 20-min procedure was developed to detect glucuronidase activity in 1,295 bacterial cultures, representing 23 genera, of strains that were isolated from clinical specimens. Very few organisms other than E. coli were MUG positive. Of 682 E. coli strains that were isolated, 630 (92.4%) were MUG positive. When an additional 188 E. coli serotype O157 isolates were examined, 155 E. coli O157:H7, 10 E. coli O157:H-, and 1 E. coli O157:H (rough) isolate were MUG negative. All 166 cultures were verocytotoxin positive. Of the remaining 22 E. coli O157 isolates, 2 isolates were O157:H-, 1 isolate was O157:H (rough), and 19 isolates were other H types (H6, H16, H19, H25, H42, and H45); these 22 isolates were MUG positive. All 22 cultures were verocytotoxin negative. The rapid MUG procedure can be used to predict verocytotoxin-positive isolates of E. coli O157; that is, there is a very good likelihood that MUG-negative E. coli O157 isolates are verocytotoxin positive.

Bacterial Toxins↗
PubMed1990

Use of tri-gas incubator for routine culture of Campylobacter species from fecal specimens.

We evaluated a tri-gas incubator for Campylobacter isolation to be used instead of an anaerobic jar. Fecal specimens were cultured in duplicate onto charcoal selective medium and incubated at 43 degrees C for 48 h in two different environments: a tri-gas incubator (Forma Scientific) adjusted to provide an atmosphere of 10% CO2, 10% O2, and the balance N2; and evacuated anaerobic jars with a replacement gas mixture of 10% CO2, 5% O2, and 85% N2. A total of 106 Campylobacter jejuni and 8 Campylobacter coli isolates were obtained from 2,348 stool specimens. Of the positive specimens, 113 isolates came from the incubator and 111 isolates came from the anaerobic jars. An additional 32 previously positive specimens were replated onto charcoal selective medium and retested by both methods. We recovered 27 C. jejuni isolates, 26 isolates by each method. The isolates from the incubator typically produced discrete colonies, while the isolates from the anaerobic jar showed some degree of swarming in colony formation. The tri-gas incubator provided a cost-effective method for culturing Campylobacter spp.

Bacteriological Techniques↗