Controlled evaluation of the volume of blood cultured in detection of bacteremia and fungemia

To evaluate the role of the volume of blood cultured in the detection of clinically important bacteremia and fungemia in adults, we evaluated the yield and speed of detection of microorganisms from 5,317 paired 2- and 5-ml samples of blood. The same kind of medium (supplemented peptone broth with 0.03% sodium polyanetholsulfonate) and atmosphere of incubation (open venting units) were used for all blood cultures. Only adequately filled (less than or equal to 80% of stated volume) sets (20-ml tube and 50-ml bottle) were compared statistically. Significantly more bacteria (p less than 0.01), Pseudomonas spp. In particular (P less than 0.05), were isolated from the 5-ml samples of blood. We conclude that the volume of blood cultured is a critical factor in the detection of septicemia. Consequently, valid evaluation of other factors influencing the detection of septicemia must be based on comparisons in which equal volumes of blood are cultured.

Comparison of atmospheres of incubation for primary isolation of Campylobacter fetus subsp. jejuni from animal specimens: 5% oxygen versus candle jar

An atmosphere with reduced oxygen tension is required for the primary isolation of Campylobacter fetus subsp. jejuni. Therefore, we compared use of the conventional atmosphere of 5% oxygen and 8% carbon dioxide with use of a candle jar (17% oxygen and 3% carbon dioxide) for primary isolation of C. fetus subsp. jejuni from 263 positive canine, cattle, and turkey fecal or cecal specimens. At an incubation temperature of 42 degrees C, the atmosphere with 5% oxygen resulted in more Campylobacter colonies per plate (P less than 0.005) and consistently larger Campylobacter colonies (P less than 0.005) than did the candle jar, whereas the growth of interfering flora was similar. Overall, 96% of the 263 specimens were positive for C. fetus subsp. jejuni with 5% oxygen, and 90% were positive with the candle jar (P less than 0.02). More striking differences in isolation rates were seen when both the temperature and the atmosphere were varied: 5% oxygen at 42 degrees C enabled recovery of 93% of the isolates from 70 positive specimens, versus 46% recovery with the candle jar at 37 degrees C. Results with 5% oxygen at 37 degrees C were intermediate. The addition of FBP supplement (0.25% each of ferrous sulfate, sodium metabisulfite, and sodium pyruvate) to Campy-BAP selective medium made no improvement over unsupplemented medium at 42 degrees C (whether in 5% oxygen or in the candle jar), but there was significant improvement over unsupplemented medium when both media were incubated at 37 degrees in the candle jar.

Hippurate hydrolysis by and triphenyltetrazolium tolerance of Campylobacter fetus

A rapid test of hippurate hydrolysis and a test of tolerance to triphenyltetrazolium chloride (TTC) were studied in 315 strains of Campylobacter fetus subsp. jejuni to determine their usefulness for biotyping this organism and for distinguishing it from C. fetus subsp. intestinalis. Of the 315 strains tested, 84% hydrolyzed hippurate and 97% were resistant to TTC. Ability to hydrolyze hippurate was seen in 99% of 155 human isolates, 75% of 60 avian isolates, 100% of 41 cattle and dog isolates, 84% of 31 zoo mammal isolates, and none of 28 hog isolates. Resistance to 400 micrograms of TTC per ml was seen in 97% of the human isolates, 95% of the avian isolates, and 100% of the mammalian isolates (other than human). In no case did any of the 315 isolates of C. fetus subsp. jejuni show both lack of ability to hydrolyze hippurate and sensitivity to TTC. In contrast, all 18 strains of C. fetus subsp. intestinalis failed to hydrolyze hippurate and were sensitive to TTC. These two tests may be useful to distinguish between C. fetus subsp. jejuni and subsp. intestinalis and also to biotype strains of C. fetus subsp. jejuni.

Isolation of Campylobacter fetus subsp jejuni from zoo animals

Over a 1-year period, 619 fecal specimens from animals at the Denver Zoo were cultured for Campylobacter fetus subsp jejuni. The organism was isolated from 35 animals, including 12 primates, 2 felids, a red panda, 13 hooved animals, 6 birds, and 1 reptile. Of 44 cultured fecal specimens from diarrheal animals, 31.8% were positive for Campylobacter, whereas only 5.6% of 575 specimens from animals without diarrhea were positive (P less than 0.001). Among 25 isolates tested, 12 serotypes were represented; several of these serotypes are commonly associated with Campylobacter enteritis in human beings. Campylobacter fetus subsp jejuni was isolated from 8% of 75 wild pigeons trapped on the zoo premises during winter months and from 26% of 75 trapped during March and April (P less than 0.01).

Evaluation of transport and storage techniques for isolation of Campylobacter fetus subsp. jejuni from turkey cecal specimens

Immediate culturing of fecal specimens is not always possible, and appropriate methods for transport and storage of Campylobacter fetus subsp. jejuni specimens have not been fully evaluated. Using nine techniques, we studied the survival of C. fetus subsp. jejuni in cecal specimens from infected turkeys. The organisms survived in specimens held without transport medium for 3 to 15 days (median, 9 days) at 4 degrees C, and 2 to 9 days (median, 4 days) at 25 degrees C. Only 20% of specimens frozen for 24 h at either -20 or -70 degrees C yielded C. fetus subsp. jejuni. Specimens dried on filter paper strips were negative for C. fetus subsp. jejuni within 1.5 h. Cary-Blair medium with decreased agar was the best of the six transport media tested, it enabled recovery of the organism from 100% (3 days) and 71% (7 days) of cecal samples held at 4 degrees C and 94% (3 days) and 85% (7 days) of cecal specimens held at 25 degrees C. In contrast, more than half of all cecal specimens held at 4 or 25 degrees C in Culturettes or buffered glycerol saline were negative by 3 days, and all were negative at 7 days. Results with the other three media studied (Campy-thio, thioglycolate medium, and alkaline peptone water) were intermediate. Overnight incubation of specimens in alkaline peptone water at 37 or 42 degrees C did not enhance recovery of C. fetus subsp. jejuni. Therefore, refrigeration without a transport medium is satisfactory for up to 3 days for recovery of C. fetus subsp. jejuni from specimens, however, we recommend the use of Cary-Blair medium with decreased agar for specimens that must be transported or stored for longer than 3 days and for rectal swabs, to prevent drying.

Campylobacter fetus subsp. jejuni in a turkey processing plant

Cecal cultures taken over a 1-year period from 600 turkeys at a poultry processing plant were all positive for Campylobacter fetus subsp. jejuni. Swabs of the cloaca and fresh feces were likewise all positive. Of 33 freshly dressed turkey carcases, 94% were positive before chilling in tanks of chlorinated ice and water; 34% of 83 carcasses were still positive after overnight soaking in the tanks. Increasing the chlorine content from 50 to 340 ppm (50 to 340 micrograms/ml) did not cause a decrease in the number of positive carcasses. C. fetus subsp. jejuni was isolated from wastewater gutters as well as from chutes and conveyor belts in the packaging room. Water samples from the five water treatment lagoons for the plant were all positive for C. fetus subsp. jejuni while the plant was in operation, but 4 days after the plant closed for the winter, all water samples were negative.

Isolation of Campylobacter fetus subsp. jejuni from migratory waterfowl

Since the sources from which humans acquire Campylobacter enteritis are only partially known, we studied the frequency of carriage of Campylobacter fetus subsp. jejuni in migratory waterfowl. Cecal contents of various species of wild ducks were cultured on selective media that contained antibiotics to inhibit normal flora. Thirty-five percent of the 445 ducks cultured harbored C. fetus subsp. jejuni. Migratory waterfowl are yet another reservoir for this enteric pathogen and may be of public health importance for humans in the contamination of water or when used as food.

Enriched brucella medium for storage and transport of cultures of Campylobacter fetus subsp. jejuni

A semisolid brucella medium with 10% sheep blood was used for storage and transport of Campylobacter fetus subsp. jejuni and subsp. intestinalis and kept isolated alive about 3 weeks or longer at 25 degrees C or when sent through the regular mail.

Reservoirs for human campylobacteriosis

The epidemiology of human enteric infection due to Campylobacter fetus subspecies jejuni is not well understood. To determine whether an endogenous human reservoir is present, the rate of isolation of C. fetus subspecies jejuni from several populations of diarrheal and asymptomatic adults and children were compared. C. fetus subspecies jejuni was recovered from 4.1% of patients with diarrhea and 66.7% of household contacts of the index patients who themselves had diarrhea. Carriage of organisms in most untreated patients lasted less than three weeks from onset of symptoms. C. fetus subspecies jejuni was rarely recovered from the feces of asymptomatic individuals and not at all from the vaginal flora of 272 women. Domestic animals, especially puppies with diarrhea, were frequently infected with Campylobacter and may represent a significant reservoir for human infection.

Survival of Campylobacter fetus subsp. jejuni in biological milieus

To provide new information on the epidemiology and pathophysiology of human infection with Campylobacter fetus subsp. jejuni, we studied its survival in several milieus. Standard inocula of organisms were placed in hydrochloric acid, human bile and urine, bovine milk, or stream water and kept at 4, 25, or 37 degrees C; viable organisms were then counted. Stools from humans infected with Campylobacter were similarly tested. Survival in acid was pH and time dependent, with 7-log kill within 5 min in solutions at pH 2.3. Organisms multiplied in bile at 37 degrees C and survived for 2 months. Organisms survived better in feces, milk, water, and urine kept at 4 degrees C than they did in these milieus at 25 degrees C. Maximal viabilities of Campylobacter organisms kept at 4 degrees C were 3 weeks in feces, 3 weeks in milk, 4 weeks in water, and 5 weeks in urine. Study results suggest that when these milieus are contaminated with C. fetus subsp. jejuni, they may be significant environmental reservoirs.

Acute colitis caused by Campylobacter fetus ss. jejuni

Campylobacter fetus ss. jejuni has been recently recognized as a common human enteric pathogen; however, the pathology and pathophysiology of the enteritis caused by this agent are still largely obscure. We report 4 patients who presented with acute abdominal pain and bloody diarrhea and who had C. fetus ss. jejuni isolated from fecal cultures. Each patient showed a fourfold rise in serum IgG titer to the organism isolated. In all 4 patients colonic involvement was noted on sigmoidoscopic examination. Biopsy specimens showed acute colitis with inflammatory infiltrates of the lamina propria and crypt abscesses. Clinical improvement was complete in all patients after therapy with erythromycin. These results suggest that clinicians should consider Campylobacter enteritis in the differential diagnois of acute colitis.

Campylobacter enteritis associated with unpasteurized milk

Campylobacter fetus ss. jejuni has recently been recognized as a human enteric pathogen. Laboratory isolation has been hindered by its fastidious nature. Methods for recovery of this organism from stool culture and a specific serologic test are described. An outbreak is reported in which three members of the same family became simultaneously ill with fever, severe abdominal cramps and diarrhea. C. fetus ss. jejuni was recovered from stool specimens from all three. A fourfold increase in serum immunoglobulin G (IgG) titer to this organism was demonstrated in each patient. All three patients had been consuming unpasteurized milk from a cow whose feces were infected with C. fetus ss. jejuni.

Campylobacter enteritis: clinical and epidemiologic features

Campylobacter fetus subspecies (ssp.) jejuni has been recently recognized to cause diarrheal disease in man. To assess its importance as an enteric pathogen, we prospectively studied 514 patients with diarrhea. Campylobacter fetus ssp. jejuni was isolated from the feces of 26 patients (5%) and seven of 11 of their symptomatic household contacts. This organism was isolated from the feces of only one of 18 asymptomatic household contacts and not at all from 157 other healthy persons. Seventeen of 20 patients from whom C. fetus ssp. jejuni was isolated from fecal culture showed at least a fourfold rise in specific IgG titers. Review of 35 cases of campylobacter enteritis identified a typical clinical syndrome with acute onset of diarrhea, abdominal pain, fever, and constitutional symptoms. Stool examination revealed blood in 60% and polymorphonuclear leukocytes in 78% of patients. Epidemiologic investigation strongly suggested an external source for the infection in 22 of 35 patients.

Growth, survival, and resistance of the Legionnaires' disease bacterium

The Legionnaires' disease (LD) bacterium can now be readily cultured on artificial media. Studies were done to define the growth and survival of the LD bacterium in these media and ascertain its susceptibility to disinfecting agents. Growth-curve studies of the Philadelphia 1 strain using Mueller-Hinton broth with ferric pyrophosphate and L-cysteine (Feeley-Gorman broth) showed a lag phase of less than 24 h, a generation time of 3.8 h during the logarithmic phase, a plateau of 2 x 10(7) organisms per millilitre, and continued viability for as long as 110 d. Viability on chocolate agar with 1% hemoglobin and 2% IsoVitaleX added reached 150 d. This strain was susceptible to a variety of commonly recommended hospital and laboratory disinfectants, often in low concentrations. These investigations suggest that prolonged survival may occur in natural as well as artificial milieus and that low concentrations of phenolics, quaternary ammonium compounds, glutaraldehyde, formaldehyde, and hypochlorite could eradicate potential reservoirs for human infection.

Campylobacter enteritis associated with canine infection

Campylobacter fetus ss. jejuni has recently been recognised as a human enteric pathogen. Five cases of campylobacter enteritis are described. All five patients had abdominal pain and diarrhoea. Two of the five patients had bloody diarrhoea and relapses. All the patients had been in contact with young dogs which had had diarrhoea. Campylobacter fetus ss. jejuni was isolated from these dogs or from their litter-mates. Canine infection with Campylobacter fetus ss. jejuni may be an important source of infection causing diarrhoea in man.

Susceptibility of Clostridium perfringens isolated from human infections to twenty antibiotics

The proper choice of antibiotic for Clostridium perfringens infections in patients allergic to penicillin is not clear; the usual recommendations and recent in vitro studies disagree. We tested the susceptibility of 57 strains of C. perfringens to eight penicillins, seven cephalosporins, two tetracyclines, clindamycin, chloramphenicol, and rifampin by the agar dilution method. All strains were inhibited by (per milliliter) 4 mug or less of any of the penicillins, chloramphenicol, or clindamycin and 8 mug or less of any of the cephalosporins tested. Penicillin G and amoxicillin inhibited all strains at 0.12 mug or less per ml. Only 54% of the strains were inhibited by 1 mug of tetracycline per ml. Penicillin G remains the drug of first choice for infections with C. perfringens; it need not be added to a regimen containing a penicillinase-resistant penicillin given parenterally in high doses. The cephalosporins should be considered as alternative drugs for penicillin-allergic patients. Clindamycin and chloramphenicol are also effective. Tetracyclines cannot be depended upon in clostridial infections without in vitro testing, which is impracticable for initial empirical therapy.

Susceptibility of Propionibacterium acnes to seventeen antibiotics

The in vitro susceptibility of 96 isolates of Propionibacterium acnes to 17 antibiotics was determined by utilizing an agar dilution technique. With the exception of the aminoglycosides, these organisms are susceptible to virtually all of the commonly used antimicrobial agents.

Limulus amebocyte lysate test in neonates

The limulus amebocyte lysate test for endotoxin was done on samples of blood from 22 well babies and 33 neonates in an intensive-care nursery. The objective was to determine whether falsely positive test results occurred in samples from newborn infants during acquisition of usual bowel flora. One neonate had a transiently positive limulus amebocyte lysate test; he had clinical signs of spesis, but no bacteremia could be documented. Unlike the nitroblue tetrazolium test, the limulus amebocyte lysate test does not appear to be regularly positive in neonates. The sensitivity of the test in detection of endotoxemia associated with gram-negative spesis in the neonate remains to be determined in a large prospective study.

Human oral defenses against gram-negative rods

Gram-negative rods are unusual pharyngeal isolates in normal man, which suggests the presence of effective oral defense mechanisms against these organisms. To understand this protection better, we studied the elimination of gram-negative rods from the mouth after gargle challenge. Suspensions of Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis (108 organisms per ml) were gargled by normal volunteers, and pharyngeal swabs for serial quantitative cultures were taken for 3 hours. Initial swabs yielded approximately 10(5) organisms. Bacterial counts rapidly decreased, and less than 1 per cent of the original inoculum was still recoverable 3 hours later. Studies of tongue, pharynx, and buccal mucosa samples showed the most rapid decrease in buccal mucosa samples and the slowest decrease in tongue swabs. To evaluate physical clearance, gargle challenges were performed using E. coli radiolabeled with technetium-99m. External counts of the oral cavity decreased rapidly, with 21.8, 14.7, 8.9, and 7.8 percent of the initial counts remaining at 30, 60, 120, and 180 min, respectively. Nonpiliated E. coli adhered poorly to buccal epithelial cells in vitro, in contrast to good adherence when piliated strains were tested. Despite these findings, no differences in radiolabel clearance was noted in vivo using piliated and nonpiliated E. coli for gargle challenges. Normal oral defenses against gram-negative rods are highly effective and seem to involve both physical clearance and local bactericidal activity.

Chloroplast genes in Chlamydomonas affecting organelle ribosomes. Genetic and biochemical analysis of analysis of antibiotic-resistant mutants at several gene loci

Six chloroplast gene mutants of Chlamydomonas reinhardtii resistant to spectinomycin, erythromycin, or streptomycin have been assessed for antibiotic resistance of their chloroplast ribosomes. Four of these mutations clearly confer high levels of antibiotic resistance on the chloroplast ribosomes both in vivo. Although one mutant resistant to streptomycin and one resistant to spectinomycin have chloroplast ribosomes as sensitive to antibiotics as those of wild type in vivo, these mutations can be shown to alter the wildtype sensitivity of chloroplast ribosomes in polynucleotide-directed amino acid incorporation in vitro. Genetic analysis of these six chloroplast mutants and three similar mutants (Sager, 1972), two of which have been shown to affect chloroplast ribosomes (Mets and Bogorad, 1972; Schlanger and Sager, 1974), indicates that in Chlamydomonas at least three chloroplast gene loci can affect streptomycin resistance of chloroplast ribosomes and that two can affect erythromycin resistance. The three spectinomycin-resistant mutants examined appear to be alleles at a single chloroplast gene locus, but may represent mutations at two different sites within the same gene. Unlike wild type, the streptomycin and spectinomycin resistant mutants which have chloroplast ribosomes sensitive to antibiotics in vivo, grow well in the presence of antibiotic by respiring exogenously supplied acetate as a carbon source, and have normal levels of cytochrome oxidase activity and cyanide-sensitive respiration. We conclude that mitochondrial protein synthesis in these mutants is resistant to these antibiotics, whereas in wild type it is sensitive. To explain the behavior of these two chloroplast gene mutants as well as other one-step mutants which are resistant both photosynthetically and when respiring acetate in the dark, we have postulated that a mutation in a single chloroplast gene may result in alteration of both chloroplast and mitochondrial ribosomes. Mitochondrial resistance would appear to be the minimal necessary condition for survival of all such mutants, and antibiotic-resistant chloroplast ribosomes would be necessary for survival only under photosynthetic conditions.

Genetic control of chlorophyll biosynthesis in Chlamydomonas. Analysis of mutants at two loci mediating the conversion of protoporphyrin-IX to magnesium protoporphyrin

In this report we describe two nonallelic Mendelian protoporphyrin accumulating mutants br(s)-1 and br(c)-1. Results of experiments with these mutants lead us to postulate that porphyrin biosynthesis branches into light and dark steps between protoporphyrin-IX and magnesium protoporphyrin. We hypothesize that the br(c) locus controls a dark step while the br(s) locus either controls a step in the main pathway before the branch or mediates the preparation of the magnesium ion for its insertion into protoporphyrin-IX. The br(s)-1 mutant is thought to be light sensitive because a block prior to the branch point in the porphyrin pathway prevents chlorophyll formation in either the light or the dark. The br(c)-1 mutant, which also accumulates protoporphyrin in the dark, forms chlorophyll and chloroplast lamellae when transferred to the light, showing that function of the porphyrin pathway is normal in the light.