Evaluation of transport media for Campylobacter jejuni in human fecal specimens

It is not always possible to culture feces immediately, and appropriate methods for transport of human specimens, unlike those from animals, have not been fully evaluated. Therefore, we took serial subcultures in two phases from six transport media inoculated with human diarrheal stools known to be positive for Campylobacter jejuni. In phase 1, Cary-Blair medium and buffered glycerol saline did not preserve C. jejuni as well as did alkaline peptone-water (APW), modified Cary-Blair medium, thioglycolate broth (Thio), and Campy-Thio. The four best media (APW, Cary-Blair medium, Thio, and Campy-Thio) preserved 20 fecal samples with C. jejuni better at 4 degrees C (90% survival for 5 to 8 days) than at 25 degrees C (90% survival for 1.7 to 2 days). In phase 2, APW and Thio, along with four modifications of the best media in phase 1, were tested with 23 positive strains. The ranges of survival times with modified media at 25 degrees C were 1.3 to 2.2 days (90%) and 4.7 to 6.8 days (50%). APW with reducing agents preserved C. jejuni better than did APW alone, Thio plus ox bile, or Campy-Thio plus ox bile (P less than 0.05). Thio at pH 8.5 was better at preserving C. jejuni than was APW or Thio plus ox bile (P less than 0.05). If human fecal specimens cannot be refrigerated during transport or storage, we recommend the use of Thio at pH 8.5 or APW with reducing agents for preservation of C. jejuni at 25 degrees C.

Controlled evaluation of hypertonic sucrose medium at a 1:5 ratio of blood to broth for detection of bacteremia and fungemia in supplemented peptone broth

The value of hypertonic media in the detection of bacteremia and fungemia is controversial, since prior clinical trials have yielded conflicting results with different media. Earlier, we showed that the addition of 10% sucrose to supplemented peptone broth at a 1:10 ratio of blood to broth yielded better recovery of Staphylococcus epidermidis, the Enterobacteriaceae, Pseudomonas aeruginosa, and yeasts. To evaluate the effect of 10% sucrose on blood cultured at a 1:5 ratio, we compared the yield and speed of detection of clinically important microorganisms from adult patients in 5,839 blood samples cultured in supplemented peptone broth with 0.03% sodium polyanetholesulfonate with and without 10% sucrose. The atmosphere of incubation (open venting units), 1:5 ratio of blood to broth, and methods of processing were the same for both bottles. Recovery of facultative gram-positive (P less than 0.02) and gram-negative (P less than 0.02) bacteria was improved, but the recovery of anaerobic gram-negative bacteria was both reduced (P less than 0.01) and delayed (P less than 0.02) by sucrose. The total yield of microorganisms including fungi, however, was increased with sucrose. The effect of sucrose on blood cultures appears to depend on the ratio of blood to broth as well as on the medium used and strains of microorganisms encountered.

Serologic study of two clusters of infection due to Campylobacter jejuni

The serologic responses to Campylobacter jejuni in persons involved in two clusters of infection and in control subjects were studied. In the first cluster, in which previously unexposed persons drank raw milk, the attack rate was high and elevated complement-fixing (CF) and specific IgG and IgM antibodies were demonstrated. In the second cluster, involving farmers who chronically drank raw milk, the attack rate was low, but titers of CF and IgG antibodies were high in both affected and unaffected persons. At a control dairy farm, where raw milk was drunk regularly, asymptomatic infection and high CF titers were demonstrated. In contrast to the findings in the first cluster, the titers of IgM antibody among the dairy farmers were low. These studies suggest that chronic exposure to C. jejuni may lead to immunity that may possibly be mediated by IgG.

Effects of disinfectants on Campylobacter jejuni

Because of the increasing recognition that Campylobacter jejuni is an important enteric pathogen of humans, we studied the effects of widely used disinfectants on the viability of this organism. At an inoculum size of 10(3) to 10(4) CFU/ml, 1.25 mg of hypochlorite per liter killed three strains within 1 min. At an inoculum size of 10(6) to 10(7) CFU/ml, 5 mg of hypochlorite per liter killed three strains within 15 min. Killing of similar concentrations of C. jejuni and Escherichia coli by hypochlorite was approximately the same. At the high inoculum, 0.15% phenolic compound, 10 mg of iodophor per liter, 1:50,000 quaternary ammonium compound, 70% ethyl alcohol, and 0.125% glutaraldehyde killed all three strains within 1 min. These studies demonstrate that, under the conditions we tested (pH 7.0; 24 to 26 degrees C), the recommended standard concentrations of disinfecting agents are adequate to destroy C. jejuni.

Effect of incubation atmosphere and temperature on isolation of Campylobacter jejuni from human stools

To determine the optimal conditions for isolation of Campylobacter jejuni from human fecal specimens, we compared incubation atmospheres that contained about 5, 10, and 15% oxygen with the 17% oxygen produced in candle jars and also compared incubation temperatures of 37 and 42 degrees C. At 42 degrees C, C. jejuni was isolated from all 16 specimens; however, colony sizes were larger when plates were incubated in 5 and 10% oxygen than in the other two atmospheres. At 37 degrees C some positive cultures were missed in 15% oxygen and in the candle jar. The largest colony sizes were obtained in 5% oxygen. For each atmospheric condition tested, the colonies were larger at 42 than at 37 degrees C. When incubation is done at 42 degrees C, use of a candle jar is adequate; however, at 37 degrees C candle jars should not be used for isolation of C. jejuni from human feces.

Experimental Campylobacter jejuni infection of adult mice

HA-ICR adult mice were studied to develop an animal model for Campylobacter jejuni enteritis in humans. Fecal and ileal cultures made by selective and nonselective methods showed that C. jejuni and related organisms are not bowel commensals. Intragastric feeding of 10(8) CFU of three different strains of C. jejuni produced infection in 100% of the animals, and infection rates were dose dependent. Pretreatment with antibiotics or opiates was not necessary to induce infection. Fresh isolates and strains passed on artificial media yielded similar infection rates. Infected mice did not show signs of illness, but transient bacteremia within 10 min of oral infection was observed in nearly 100%. The small intestine was the principal target organ, with epithelial inflammation seen 48 h after infection. Control mice of four species had undetectable serum immunoglobulin G antibody specific for the infecting strain, but infected mice showed peak titers at 1 week with rapid decline. Immunoglobulin M titers rose minimally, and immunoglobulin A titers did not rise. Infected mice uniformly became chronic asymptomatic excretors, shedding 10(4) to 10(6) CFU/g of feces; a minority were biliary carriers. Intestine carriage was most pronounced in the stomach and proximal small intestine. Because this experimental infection led to bacteremia, transient pathological changes, and immunoglobulin G titer rises, this model may be useful for evaluating the effects of prophylactic and therapeutic interventions.

Controlled evaluation of the effect of atmosphere of incubation on detection of bacteremia and fungemia in supplemented peptone broth

To evaluate the role of atmosphere of incubation in the detection of clinically important bacteremia and fungemia in adults, we compared the yield of microorganisms from 10,541 paired 5-ml samples of blood incubated aerobically and anaerobically. The medium, supplemented peptone broth (SPB) with 0.03% sodium polyanetholesulfonate, and the ratio of blood to broth (1:10) were the same for all cultures. Only cultures with adequate blood samples (greater than or equal to 80% of stated volume) were compared statistically. More fungi (P less than 10(-7) ) grew in continuously vented bottles of SPB. Aerobic incubation also favored (P less than 0.01) isolation of Neisseria gonorrhoeae and Eubacterium; more than 80% of these bacterial organisms were detected only in vented bottles. Anaerobic incubation (plugged venting units) did not significantly favor the isolation of any genus of microorganisms, although an estimated 11% more Bacteroidaceae grew in the unvented bottle of SPB. By comparison of our data with published results for other media, we conclude that the need for both aerobic and anaerobic incubation of blood cultures is dependent upon the medium used and the microorganisms likely to be encountered. Vented incubation of blood cultured in SPB is crucial for detection of fungi and some bacteria. Routine use of an unvented bottle of SPB may not be worthwhile for patients in whom Bacteroidaceae cause bacteremia infrequently. However, when Bacteroidaceae are suspected as the cause of sepsis, use of an unvented bottle of SPB is prudent.

Controlled evaluation of hypertonic sucrose medium for detection of bacteremia and fungemia in supplemented peptone broth

Because the value of hypertonic media in detection of bacteremia and fungemia is controversial, we evaluated supplemented peptone broth (SPB) with 0.03% sodium polyanetholsulfonate with and without 10% sucrose in 5,439 paired blood cultures from adult patients. The aerobic atmosphere, 1:10 ratio of blood to broth, and methods for processing blood cultures were identical. Only cultures with adequate blood samples (greater than or equal to 4 ml) were compared statistically. More clinically important bacteria were recovered from SPB with sucrose (P less than or equal to 0.001), including Staphylococcus epidermidis, Enterobacteriaceae, and Bacteroidaceae. However, only one of nine isolates of Neisseria gonorrhoeae grew in SPB with sucrose. Staphylococci (P less than 0.001), Enterobacteriaceae (P less than 0.01), Pseudomonas aeruginosa (P less than 0.01), and yeasts (P less than 0.05) were detected 1 or more days earlier in SPB with sucrose. The effect of sucrose on blood cultures appears to be medium dependent, based on comparisons of our results with those of published reports.

Comparison of CampyPak II with standard 5% oxygen and candle jars for growth of Campylobacter jejuni from human feces

To determine optimal temperature and atmospheric conditions for isolating Campylobacter jejuni from fecal specimens of humans, we studied six laboratory isolates and 19 fecal specimens that were known to contain C. jejuni. We compared incubations in 5% oxygen, the CampyPak II (BBL Microbiology Systems, Cockeysville, Md.) with 6 plates per jar (CP-6) and 12 plates per jar (CP-12), and candle jars at 37 and 42 degrees C. At both temperatures, the colony sizes for the laboratory strains were larger in the 5% O2 and the CP-6 than under the other two conditions. For the primary isolations, CP-12 failed to detect one and two campylobacters at 42 and 37 degrees C, respectively, whereas the candle jar failed to detect one at 42 degrees C and four at 37 degrees C. Colony size was again larger in the 5% O2 and the CP-6. For all four atmospheric conditions tested, colonies were significantly larger at 42 degrees C than at 37 degrees C. These studies showed that incubation at 42 degrees C in either 5% O2 or the CampyPak II with six plates per jar was optimal for primary isolation of C. jejuni from fecal specimens of humans. The candle jars incubated at 42 degrees C appeared to be satisfactory for primary isolation of C. jejuni from human feces, but incubation at 37 degrees C was not acceptable.

Comparative evaluation of supplemented peptone broth with sodium polyanetholesulfonate and trypticase soy broth with sodium amylosulfate for detection of septicemia

We compared the yield and speed of detection of clinically important microorganisms from 10,156 paired 5-ml samples of blood cultured in supplemented peptone broth (SPB) with 0.03% sodium polyanetholesulfonate (SPS) or Trypticase soy broth (TSB) with 0.5% sodium amylosulfate (SAS). The atmosphere of incubation (open venting units) and ratio of blood to broth (1:10) were the same for both samples. Only cultures with adequate blood samples (greater than or equal to 80% of stated volume) were compared statistically. Overall, SPB/SPS outperformed TSB/SAS. Bacteroidaceae and Eubacterium were found more often (P less than 0.05) and viridans streptococci were found sooner (P less than 10(-4)) in SPB/SPS than in TSB/SAS. Most importantly, staphylococci were found both more often (P less than 0.03) and sooner (P less than 10(-7)) in SPB/SPS than in TSB/SAS. In a separate experiment, SAS slowed the growth of a clinical strain of Staphylococcus aureus in TSB. Unless important advantages can be confirmed for SAS in controlled clinical trials, SAS cannot be recommended for routine use as an anticoagulant in blood culture media.

Campylobacter enteritis in Denver

To determine the relative importance of Campylobacter jejuni as a cause of diarrheal illness in patients coming to three hospitals in Denver, we cultured stool specimens from 2,670 patients over a two-year period. C jejuni was identified in the feces of 124 patients (4.6 percent), Salmonella from 90 (3.4 percent) and Shigella from 77 (2.9 percent). Most Campylobacter isolates were obtained in the summer months and from patients 10 to 29 years old. The illness usually lasted less than two weeks; predominant symptoms were diarrhea (98 percent), abdominal pain (88 percent) and fever (82 percent); patients with severe illness frequently had objective evidence of nonspecific colitis. Occult blood and leukocytes were present in stool specimens of 71 percent and 85 percent, respectively, of the patients tested. The duration and severity of illness led to antibiotic therapy in about half of the patients; erythromycin appeared effective. This study confirms the importance of C jejuni as a cause of enteritis; this microorganism should be sought routinely in fecal specimens from patients with diarrhea.

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.