Zygomycosis caused by Cunninghamella bertholletiae: mycologic aspects

Two isolates of Cunninghamella bertholletiae from confirmed cases of human zygomycosis were studied, and their sexual, asexual, and physiologic characteristics described. Minimal inhibitory concentrations for these two isolates, as well as for six other clinical isolates of C bertholletiae, were determined for amphotericin B, flucytosine, and miconazole using a standardized agar dilution technique. All isolates were found to be susceptible to miconazole, but resistant to flucytosine and amphotericin B.

Effects of pH shifts, bile salts, and glucose on sporulation of Clostridium perfringens NCTC 8798

The sporulation of Clostridium perfringens NCTC 8798 was studied after exposing vegetative cells to: pH values of 1.5 to 8.0 in fluid thioglycolate broth (for 2h) and then transferring them to Duncan-Strong (DS) sporulation medium; sodium cholate or sodium deoxycholate (0.3 to 6.5 mM) in DS medium; or Rhia-Solberg medium with 0.4% (wt/wt) starch, glucose, or both added at 0 to 55 mM. At pH 1.5, no culturable heat-resistant spores were formed. For cells exposed to pH 3.0, 4.0, 5.0, or 6.0, increases in heat-resistant spores were not seen until after a lag of 12 to 13 h, whereas the lag was only 2 to 3 h for cells exposed to pH 7.0 or 8.0. Maximal spore crops were produced after only 6 to 8 h for cells exposed to pH 7 or 8, but 16 to 18 h was required for production of maximal spore crops by cells exposed to the lower-pH media. The addition of sodium cholate (3.5 to 6.5 mM) to DS medium only slightly reduced the culturable heat-resistant spore count from 1.9 X 10(7) to 3 X 10(6)/ml. The addition of 1.8 mM or more sodium deoxycholate reduced the culturable heat-resistant spore count to less than 10/ ml. When either starch or glucose alone was added to Rhia-Solberg medium there was no production of culturable heat-resistant spores, but a combination of 0.4% (wt/wt) starch and 4.4 mM glucose yielded 6 X 10(5) spores/ml. The spore production remained at this level for glucose concentrations of 6 to 22 mM, but then declined to about 3 X 10(3) spores per ml at higher concentrations.

Quantitative, radial diffusion slide assay for staphylocoagulase

A simple, quantitative radial diffusion assay for staphylocoagulase in culture fluids, using microscope slides coated with a thin layer of agar containing plasma and fibrinogen, was developed. No prior purification of the enzyme was needed, and only small quantities, 7 microliter, were required for each test. This method is particularly suitable for objectively comparing the relative amounts of coagulase produced by different cultures of Staphylococcus aureus.

Cardiobacterium hominis endocarditis

This report describes the isolation of Cardiobacterium hominis from a patient with a history of rheumatic heart disease. Seven blood cultures yielded the organism. This investigation includes the case history, significant details of the hospital course, and the bacteriological, biochemical, and antimicrobial characteristics of Cardiobacterium hominis, integrated with a brief review of the literature.

Difference in Injury of Cells of Vibrio parahaemolyticus Produced by Heat and Cold Stresses in liquid and Solid Menstrual 1

Cells of Vibrio parahaemolyticus were stressed by heat, cold or heat-cold treatments of 45 C for 12 h, 0 C for 24 h or both. The five menstrua in which cells were stressed were 0.1 M phosphate buffer with 3% NaCl (B + 3%), 0.25 - strength Marine Broth (0.25 × MB) Trypticase Soy Broth with 3% NaCl (TSB + 3%) and Trypticase Soy Agar with 3 or 7% NaCl (TSA + 3% or TSA + 7%). The chill stress produced no cell injury, measured as the difference in colony counts in TSA+3% and TSA+7%, in the three liquid menstrua but caused more than 4 logs of cell injury in the solid menstrua compared to controls. The heat stress caused 2.5- and 1.5-log increases in the number of injured cells from B + 3% or 0.25 × MB, respectively. Cells heat-stressed in TSB + 3% showed no decline in colony counts, but those heat-stressed in TSA+ 7% produced about a 6-log lower colony count. For cells heated and then chilled in B+3% or 0.25 × MB as the liquid menstruum, the percentages of heat-injured cells that apparently regained tolerance to 7% NaCl when shifted to the cold were about 99.7 and 95.0%, respectively. Conversely, cells that were heated and then chilled in the solid menstrua did not regain tolerance to 7% NaCl. Thus, cell injury was greater and apparently less easily reversed for cells stressed in solid than liquid menstrua.

Microbial Persistence on Inoculated Beef Plates Sprayed with Hypochlorite Solutions

Exterior surfaces of beef plates were inoculated with aerobic mesophilic, psychrotrophic, coliform, fecal coliform and Staphylococcus aureus bacteria before spraying with city water (7.03 kg/cm²) or with 100, 150 or 200 ppm hypochlorite solutions applied at 3.75, 5.25 or 7.03 kg/cm²) for 12 sec. Surface strips excised from the inoculated carcass regions were analyzed for bacterial persistence at 2 hand 2,4,8,16 and 20 days after spray treatment. A one log. or greater, reduction incoliforms, fecal coliforms and S. aureus counts occurred within 4 days for each spray treatment. Initial aerobic mesophilic and psychrotrophic counts were reduced by < 1 log within 2 h but increased to original inoculum levels within 8 days for each treatment. Mesophilic and psychrotrophic counts increased to > 3.5 logs higher than inoculated levels after 16 days at 4-6 C. Spray pressure (P < .01) was more effective in reducing mesophilic, psychrotrophic and S. aureus counts than was hypochlorite concentration (P < .05) while both variables were about equally effective against coliforms (P < .01) and fecal coliforms (P < .05). Surprisingly, reductions of psychrotrophic, coliform and S. aureus counts on the beef carcass surface sprayed with hypochlorite solutions were not significantly (P < .05) different from those observed on carcasses sprayed with city water. However, a significantly (P < .05) greater reduction in aerobic mesophile and fecal coliform counts at 2 days after treatment was obtained when using the intermediate spray pressure of 5.25 kg/cm² containing 200 ppm hypochlorite, rather than city water. No undesirable change in beef grade, muscle shear or color property was observed for carcasses treated with the hypochlorite solutions.

Bacteriological Survey of Raw "Soul Foods" Available in South Carolina

Bacterial counts of "soul foods" obtained from 10 farm families and 10 supermarkets were determined. Total plate count means for farm family vegetables ranged from 1.5 × 10⁶/g to 2.9 × 10⁶/g, and 2.0 × 10²/g to 3.1 × 10⁵/g for vegetables purchased at the retail sales establishments. Pig offal samples with the highest total plate counts were pigtails, 4.8 × 10⁸/g and maws, 4.5 × 10⁸/g from farm families; and pigtails, 2.8 × 10⁹/g, neck bones, 2.4 × 10⁹/g from the retail sources. Fecal coliforms were not detected in any of the vegetable samples but were isolated from 24% of the pig offals. Sixty percent of all of the foods were positive for Salmonella and 96% were positive for coagulase-positive Staphylococcus aureus . Clostridium perfringens was only detected in one sample, chitterlings from a retail source.

Incidence of airborne Aspergillus flavus spores in cornfields of five states

Airborne Aspergillus flavus spores were rarely detected throughout the 1975 growing season by the agar plate method at cornfield sites in Georgia, Illinois, Maryland, South Carolina, and Virginia.

Regional pancreatic concentration and in-vitro secretion of canine pancreatic polypeptide, insulin, and glucagon

The regional concentrations and in-vitro secretions of canine pancreatic polypeptide (cPP), insulin, and glucagon were studied. CPP is found predominantly in the uncinate process of the dog pancreas, whereas insulin and, more markedly, glucagon predominate in the body and tail of the pancreas. In-vitro secretion studies of pancreatic pieces indicate that dibutyryl cyclic AMP (dcAMP) alone can stimulate cPP release whereas glucose and arginine alone have no effect. Arginine, but not glucose, potentiates this stimulant effect of dcAMP. These studies suggest that the cAMP generating system may play a role in regulation of cPP secretion.

Increased numbers of heat-resistnat spores produced by two strains of Clostridium perfringens bearing temperate phage s9

Sporulation kinetics and spore heat resistance data were compared for a lysogenic strain of Clostridium perfringens, s9, before and after curing with ultraviolet irradiation. The cured strain showed the same growth rate in broth media as the lysogenic strain but took 6 h longer to form refractile spores. For lysogenized and cured strains the percentages of refractile spores produced that were heat-resistant (80 degrees C for 15 min) were 50 and 0.2, respectively. When reinfected with the temperature phage, the cured strain produced spores in 2 to 3 h, like the original lysogenic culture, and 10% of the spores produced were heat-resistnat.

Characteristics of bacteria isolated by the anaerobic roll-tube method from cheeses and ground beef

In this study the methods of Hungate were used to quantitate the anaerobic bacteria present in commercially available ground beef, cheddar cheese, and German hand cheese. Of 235 anaerobic roll-tube isolates from ground beef and German hand cheese, all were facultative anaerobes. Of 213 anaerobic roll-tube isolates from cheddar cheese, 91% were facultative anaerobes and 9% were obligate anaerobes. Using results of biochemical tests, 14 or the 17 obligately anaerobic isolates from cheddar cheese were Propionibacterium acnes, two were strains of Propionibacterium that could not be speciated, and one was tentatively identified as a strain of Streptococcus evolutus. Obligate anaerobes were estimated to be present in the cheddar cheese at a level of about 10(6)/g. The possible significance of these levels of P. acnes in nonsterile foods is discussed.

Laboratory Method for Fermentation of Meat and Poultry Sausages in Fibrous Casings

The construction and operation of a relatively inexpensive cabinet for sausage fermentation studies is described. Temperature can be controlled to ±1 C with a relative humidity of approximately 95%.

Influence of temperature on steady-state growth of colonies of Pseudomonas fluorescens

Diameters of surface colonies of Pseudomonas fluorescens were observed to increase linearly with time at temperatures from 30 to 0 C.

Death of Salmonella typhimurium and Escherichia coli in the presence of freshly reconstituted dehydrated garlic and onion

The kinetics of the decline of populations of Salmonella typhimurium inoculated into freshly reconstituted dehydrated onion and garlic powders was studied. Measurable bactericidal activity was observed for onion and garlic concentrations of 1 and 5% (w/v), respectively, with maximal death rates occurring for concentrations of 5 and 10%. At these concentrations, the decimal reduction times were 1.1 and 1.2 hr, respectively, for resting cell cultures and 1.8 and 2.1 hr, respectively, for growing cultures. Of the major volatile aliphatic disulfide compounds of onions, n-propyl allyl and di-n-propyl, at concentrations of 0.1%, showed a comparable activity against resting cells but only a bacteriostatic effect toward actively growing cultures, which overcame this effect in 2 to 6 hr. At comparable concentrations, growing cultures of Escherichia coli were as susceptible to garlic, but apparently more resistant to onion, than were those of S. typhimurium.