Controlled evaluation of trypticase soy broth with and without gelatin and yeast extract in the detection of bacteremia and fungemia

The addition of gelatin to blood culture media has been suggested to prevent the inhibition of Neisseria meningitidis, Neisseria gonorrhoeae, Gardnerella vaginalis, and Peptostreptococcus anaerobius that is caused by sodium polyanetholsulfonate. To determine the effect of such supplementation on the overall yield of microorganisms, we compared the yield and speed of detection of clinically important microorganisms from 5422 paired 10-ml samples of blood cultured in Trypticase soy broth (TSB) containing 0.03% sodium polyanetholesulfonate (SPS) and TSB/SPS containing 1.2% gelatin and 1.0% yeast extract (mTSB). The atmosphere of incubation (open venting unit) and ratio of blood to broth (1:5) were the same for both samples. Only cultures with adequate blood sample (greater than or equal to 80% of stated volume) were compared statistically. Addition of gelatin and yeast extract resulted in inhibited growth of Enterobacteriaceae (p less than 0.001), Pseudomonas aeruginosa (p less than 0.01), fungi (p less than 0.05), and the overall set of microorganisms encountered (p less than 0.001). It delayed growth of Enterobacteriaceae (p less than 0.001) but reduced the time to recover staphylococci (p less than 0.02). Of 12 isolates of species usually inhibited by SPS, seven grew only with the addition of gelatin and yeast extract, none grew only without supplementation, and five grew in both media. Although gelatin and yeast extract may improve the yield of some specific bacteria, the routine use of these additives cannot be recommended for all blood culture media.

Controlled evaluation of modified radiometric blood culture medium supplemented with gelatin for detection of bacteremia and fungemia

Although the addition of 1.2% gelatin to broth blood culture media containing sodium polyanetholesulfonate has been shown to enhance detection of certain bacteria, including Neisseria meningitidis, N. gonorrhoeae, Peptostreptococcus anaerobius, and Gardnerella vaginalis, the effect of such supplementation on the detection of other microorganisms causing bacteremia and fungemia is not known. Therefore, we studied BACTEC 6B medium with and without gelatin in 6,833 paired comparisons to examine the effects of supplementation on both the yield and the speed of detection of sepsis. More aerobic and facultative bacteria grew in the 6B than in the 6B-gelatin medium (P less than 0.001), especially staphylococci (P less than 0.01), Escherichia coli (P less than 0.01), other members of the family Enterobacteriaceae (P less than 0.05), and Acinetobacter spp. (P less than 0.05). When microorganisms grew in both bottles, they did so earlier in 6B than in 6B-gelatin (P less than 0.001). We conclude that the 6B medium in its present formulation is superior to 6B medium supplemented with 1.2% gelatin.

Pathogenesis of Campylobacter fetus infections: serum resistance associated with high-molecular-weight surface proteins

Campylobacter fetus subspecies fetus causes both systemic and diarrheal illnesses. We studied 38 strains of C. fetus isolated from 34 patients; underlying illness was present in eight (89%) of nine patients with only systemic isolates compared with three (20%) of 15 patients with only fecal isolates (P = .002). In a standardized assay of susceptibility to normal human serum, 27 (71%) strains were resistant, six (16%) had intermediate susceptibility, and five (13%) were serum sensitive. Major protein bands migrating at 100 kDa or 125 kDa on polyacrylamide gels were present in all of the 25 serum-resistant strains tested but in only four of seven serum-sensitive isolates of C. fetus from humans and animals (P = .007). The presence of these bands was associated with type A lipopolysaccharide. A low-passaged strain, 82-40, was serum resistant and contained the 100-kDa protein; however, a spontaneous mutant of this strain lacked this band and was serum sensitive. The 100-kDa and 125-kDa proteins of three strains of C. fetus were antigenically cross reactive or identical and were exposed on the surface of the C. fetus cell. Serum resistance is inherent to most C. fetus isolates from humans and is associated with the presence of cross-reactive surface proteins.

Erythromycin-resistant Campylobacter infections in Thailand

Erythromycin therapy was compared with no treatment in a prospective trial of acute diarrheal disease among 100 infants in an orphanage in Bangkok. Within 24 h of the onset of diarrhea, 50 children received erythromycin ethylsuccinate (40 mg/kg per day) in four divided doses for 5 days. Campylobacter jejuni isolated from 31, Campylobacter coli isolated from 21, and Shigella spp. isolated from 21 of 100 children were the most commonly recognized pathogens; use of a sensitive, nonselective method substantially increased Campylobacter isolation. Treatment with erythromycin had no effect on the duration of diarrhea caused by Campylobacter spp., Shigella spp., or other agents; 37% of the treatment group and 35% of the control group had diarrhea for 1 week. Of 23 Campylobacter strains isolated from the treatment group before treatment, 15 (65%) were resistant (MIC, greater than or equal to 8 micrograms/ml) to erythromycin. Among orphanage-acquired strains, 53% of 43 C. jejuni strains and 91% of 23 C. coli strains were resistant to erythromycin compared with 11% of 114 C. jejuni strains and 46% of 35 C. coli strains that were community acquired. Erythromycin resistance is common among Campylobacter strains in Bangkok, especially in an institutional setting, which may account for the lack of efficacy of erythromycin for treatment of acute diarrheal illnesses.

[Ultrastructure of primary clear cell carcinoma of the liver]

Surgical specimens of 175 cases of primary hepatocellular carcinoma were prepared by routine paraffin section and HE stain. The clear cell cancer specimens were stained with PAS. All the specimens were observed by light microscope. Ultrathin sections were made for 50 samples and studied by electron microscope. Under the light microscope, 79 (45.1%) showed varying amounts of clear cells. According to the proportion and distribution of these cells, clear cell carcinoma of the liver was divided into three types: scattered type (16 cases, 20.3%), localized (43, 54.4%) and diffuse types (20, 25.3%). The clear cancer cells could be found in hepatoma with various degrees of differentiation. Of these 79 cases, 4 (5.1%) were grade I, 53 (67%) and 22 (27.9%) were grades II and III. Positive PAS stain gives an evidence of glycogen in the clear cell cytoplasm. 7 diffuse type clear cell hepatomas were observed with electron microscope. The cytoplasm had only fewer organelles, leading to a void appearance. The amount of the rough endoplasmic reticulum, free ribosome and polyribosome was markedly decreased. So was mitochondria, usually showing swelling and abnormality. The residual rough endoplasmic reticulum and mitochondria were out of normal arrangement. They often aggregated on one side of the nucleus or near the cell membrane. Glycogen particles were increased in some cell cytoplasms. Some particles were even and fine, some were aggregated into masses or scattered. Nuclei showed abnormalities mild to moderate. The nature of the clear cells in liver cancer is the variance of glycogen or lipid in the cytoplasm.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of pathogenic Campylobacter species in blood culture systems

Because differences in recognition of Campylobacter fetus and Campylobacter jejuni in systemic infections may be due partially to differences in the ability to cultivate these organisms, we studied their growth characteristics in two widely used blood culture systems. In the Roche Septi-Chek system (Hoffman-La Roche, Inc., Nutley, N.J.), over a broad range of inocula all strains were detected in broth within 2 days and on paddles within 3 days. In the BACTEC 6B aerobic bottles (Johnston Laboratories, Inc., Towson, Md.), C. jejuni and C. fetus took a median of 5 and 3 days, respectively, to reach the growth index threshold. However, in the BACTEC 7D anaerobic bottles, C. fetus required a median of 2 days to reach the growth index threshold, whereas for C. jejuni the median was greater than 10 days. The poor performance of C. jejuni in both BACTEC systems may have been due to unfavorable incubation atmospheres and may partially explain why C. jejuni bacteremia is so infrequently detected. Overall, the Roche Septi-Chek system was excellent for detecting Campylobacter strains in blood cultures.

Controlled evaluation of the agar-slide and radiometric blood culture systems for the detection of bacteremia and fungemia

A commercially available agar-slide blood culture bottle (Septi-Chek; Roche Diagnostics, Div. Hoffman-La Roche, Inc., Nutley, N.J.) was compared with the radiometric blood culture system (BACTEC; Johnston Laboratories, Inc., Towson, Md.) in 8,544 paired blood cultures from adult patients. The systems were inoculated with equal volumes (10 ml) of blood. Overall, there was no statistically significant difference between the two systems in the recovery of clinically important microorganisms, but significantly more members of the family Enterobacteriaceae other than Escherichia coli were detected by the agar-slide system (P less than 0.005). The agar-slide system detected more fungi, and the BACTEC detected more anaerobic bacteria; however, small numbers of recovered organisms precluded statistical significance. When microorganisms grew in both systems, their presence was detected one or more days earlier in the BACTEC (P less than 0.001). More contaminants grew in the agar-slide system (P less than 0.001). Both systems performed well, and either system should provide high yield and prompt detection of positive blood cultures in patients with bacteremia and fungemia if used in an optimal way as recommended by the respective manufacturers.

Inactivation of Campylobacter jejuni by chlorine and monochloramine

Campylobacter jejuni and closely related organisms are important bacterial causes of acute diarrheal illness in the United States. Both endemic and epidemic infections have been associated with consuming untreated or improperly treated surface water. We compared susceptibility of three C. jejuni strains and Escherichia coli ATCC 11229 with standard procedures used to disinfect water. Inactivation of bacterial preparations with 0.1 mg of chlorine and 1.0 mg of monochloramine per liter was determined at pH 6 and 8 and at 4 and 25 degrees C. Under virtually every condition tested, each of the three C. jejuni strains was more susceptible than the E. coli control strain, with greater than 99% inactivation after 15 min of contact with 1.0 mg of monochloramine per liter or 5 min of contact with 0.1 mg of free chlorine per liter. Results of experiments in which an antibiotic-containing medium was used suggest that a high proportion of the remaining cells were injured. An animal-passaged C. jejuni strain was as susceptible to chlorine disinfection as were laboratory-passaged strains. These results suggest that disinfection procedures commonly used for treatment of drinking water to remove coliform bacteria are adequate to eliminate C. jejuni and further correlate with the absence of outbreaks associated with properly treated water.

Clinical comparison of an agar slide blood culture bottle with tryptic soy broth and a conventional blood culture bottle with supplemented peptone broth

The Roche Septi-Chek biphasic blood culture system with tryptic soy broth was compared with a conventional blood culture bottle with supplemented peptone broth in 6,956 paired blood cultures from adult patients. Both systems were inoculated with equal volumes of blood (5 ml) and incubated aerobically (vented) for 2 weeks. More clinically important bacteria and fungi, including Staphylococcus aureus, S. epidermidis, Escherichia coli and other Enterobacteriaceae, Pseudomonas aeruginosa, and Candida albicans and C. tropicalis were recovered from the biphasic system (P less than 0.001). In contrast, more clinically important anaerobic bacteria (P less than 0.001) and Gardnerella vaginalis (P less than 0.05) were recovered in conventional supplemented peptone broth. Staphylococci (P less than 0.01), Enterobacteriaceae other than E. coli (P less than 0.05), and fungi (P less than 0.001) were detected 1 or more days earlier in the biphasic system, whereas streptococci (P less than 0.001) were detected earlier in the conventional bottle. The overall superiority of the agar slide blood culture system compared with conventional blood culture bottles was confirmed by this evaluation. For optimal detection of anaerobic bacteremia, however, the agar slide bottle should be paired with an anaerobic bottle.

Controlled evaluation of supplemented peptone and Bactec blood culture broths for the detection of bacteremia and fungemia

Comparison of conventional blood culture media with newer formulations of Bactec media for radiometric detection are lacking. Therefore, we compared the yield and speed of detection of clinically important microorganisms with supplemented peptone broth (SPB) and Bactec aerobic (6B) and anaerobic (7C or 7D) broths in 7,627 blood samples from adult patients. Acridine orange stains from SPB, radiometric readings from Bactec, and routine subcultures from all bottles were done at the same time intervals. Bactec grew more facultative gram-positive bacteria (P less than 0.02), Bacteroides spp. (P less than 0.001), gram-negative anaerobes (P less than 0.001). The two-bottle Bactec system required less time to detect Staphylococcus aureus (P less than 0.001), facultative gram-positive bacteria (P less than 0.001), Escherichia coli (P less than 0.02), facultative gram-negative bacteria (P less than .001), and fungi (P less than 0.001). Overall, Bactec yielded 11% more microorganisms and detected bacteremia sooner in 18% of samples than did SPB. This advantage was not because of radiometric monitoring, since most positive Bactec bottles were detected macroscopically. SPB offered no advantage for any group of microorganisms. We conclude that Bactec 6B and 7C or 7D broths used as a unit are superior to a single bottle of SPB with an equal volume of blood for the detection of bacteremia and fungemia, and that Bactec's superiority is not due to the method of detection.

Controlled evaluation of Trypticase soy broth in agar slide and conventional blood culture systems

A commercially available biphasic blood culture system that utilizes an attachable agar slide paddle and Trypticase soy broth (BBL Microbiology Systems, Cockeysville, Md.) was compared with a conventional Trypticase soy broth blood culture bottle in 6,867 paired blood cultures from adult patients. Both systems were inoculated with equal volumes of blood (5 ml) and incubated aerobically (vented) for 2 weeks. More clinically important bacteria and fungi, including Staphylococcus epidermidis, streptococci, Escherichia coli, Klebsiella spp., other Enterobacteriaceae, and Pseudomonas aeruginosa, were recovered from the biphasic system (P less than 0.001). In contrast, more anaerobic bacteria of importance were recovered in the conventional bottle (P less than 0.01). Staphylococci (P less than 0.001), gram-negative facultative and aerobic bacteria (P less than 0.001), and fungi (P less than 0.001) were detected 1 or more days earlier in the biphasic system, whereas pneumococci (P less than 0.05) were detected earlier in the conventional bottle. Of 603 clinically important microorganisms that grew in the biphasic system, 601 (99.7%) were detected by day 7 of incubation, but only 403 of 490 microorganisms (82.2%) were detected by day 7 in the conventional bottle. Overall, the biphasic system was superior to the conventional bottle. For optimal detection of anaerobic bacteremia, however, the biphasic system should be used in conjunction with a complementary anaerobic conventional bottle.

Surveillance for the detection of nosocomial infections and the potential for nosocomial outbreaks. II. Development of a laboratory-based system

We describe the development of a surveillance system that uses thresholds for detecting nosocomial infections and the potential for nosocomial outbreaks based on data from microbiology laboratory records at our hospital from 1980 to 1982. These records were monitored weekly to determine the number of positive isolates by the identity of the organism and by the site of the culture. A mean of 225 specimens was processed weekly, with 60 of these yielding bacteria or fungi. The average number of organisms isolated per positive culture was 1.46. Two methods of establishing thresholds were compared, one based on percentiles of ranked isolates, the other based on the mean plus intervals of standard error. The system using thresholds established by the standard error method was consistently more useful to highlight weeks for which there was high risk of a problem occurring in less time than were the surveillance techniques traditionally employed.

Role of stagnation and obstruction of water flow in isolation of Legionella pneumophila from hospital plumbing

The stagnation of water in two of four hospital hot-water storage tanks found to contain Legionella pneumophila was reduced by keeping the two tanks continually on-line for 1 year. L. pneumophila colony counts in these two tanks fell quickly to low levels, whereas the organisms persisted in the two tanks that were not in use. L. pneumophila continued to be isolated from 50 to 100% of the hospital showerheads which were sampled during this period. We also examined aerators and other hospital faucet fixtures which obstruct water flow. L. pneumophila was isolated from 22 of 30 faucet aerators and 2 of 16 vacuum breakers but not from 26 nonobstructed faucets or 6 backflow preventers. Over a 7-month period, after nine faucet aerators were sterilized, 10 of 60 surveillance cultures revealed L. pneumophila, despite the inability to isolate the organism from the potable-water tanks in use. These data suggest that prevention of stagnation in hot-water tanks may be effective in reducing L. pneumophila concentrations in potable-water systems serving high-risk populations. We have also shown that faucet aerators, by providing a surface for L. pneumophila to colonize, can become secondary reservoirs for the organism in hospital plumbing.

Comparison of antimicrobial susceptibility patterns of Campylobacter jejuni and Campylobacter coli

To determine whether employing antibiograms is useful to separate Campylobacter jejuni and Campylobacter coli, we determined the MICs of 12 antibiotics for 104 human clinical strains and 74 swine strains. Of 74 swine strains, 5 (7%) were hippurate positive, as were 93 (89%) of 104 human strains. The 12 antimicrobial agents tested were ampicillin, amoxicillin, clindamycin, chloramphenicol, erythromycin, furazolidone, norfloxacin, nalidixic acid, rosoxacin, rosaramicin, tetracycline, and Sch 32063. Isolates from humans were significantly (P less than 0.001) more susceptible than swine strains to clindamycin, erythromycin, rosaramicin, and Sch 32063. Of 11 human hippurate-negative strains, 3 (27%) were resistant to clindamycin, erythromycin, rosaramicin, and Sch 32063, compared with 1 of 93 (1%) hippurate-positive strains. Nearly all human and swine strains were susceptible to furazolidone and nalidixic acid. Campylobacter isolates from humans and swine have different antibiograms, and the susceptibility to certain antibiotics, such as clindamycin, may be helpful for differentiation of C. jejuni from C. coli.

Comparison of methods for recovery of Escherichia coli and Staphylococcus aureus from seeded laundry fabrics

To assess the effect of laundry procedures on fabric-associated bacteria, a standard method of enumeration is needed. We evaluated six methods for enumeration of Escherichia coli and Staphylococcus aureus seeded (10(2) and 10(5) CFU/100 cm2 of fabric area) onto sterilized hospital sheets and terry . Two methods involved maceration of seeded swatches in broth followed by passage of the broth through a 0.45-micron-pore-size, 47-mm-diameter filter membrane. Three methods involved agitation of seeded swatches in broth with a paint shaker and membrane filtration of the broth to recover eluted bacterial cells, and the final method involved direct enumeration of cells on fabrics by overlaying seeded swatches with agar containing triphenyltetrazolium chloride as an indicator. The most convenient recovery method employed a 90-s agitation followed by serial dilution of broths and membrane filtration. This method provided 44/57% (low seed/high seed) recovery of E. coli from sheets and 133/31% from terry and 34/74% recovery of S. aureus from sheets and 58/57% from terry . Although maceration provided similar recovery of E. coli and S. aureus, it is a less-practical method. The direct enumeration method was ineffective for enumerating gram-positive bacteria. We conclude that either the agitation or maceration method used enumerated the seeded bacteria to within 1 log10 of their expected number and can be used to assess the bactericidal effectiveness of various steps in the laundering process.

Killing of fabric-associated bacteria in hospital laundry by low-temperature washing

Hospitals using 71.1 C water for laundering consume vast amounts of energy. We studied whether washing at 22 C would result in fabric-associated bacterial counts significantly different from those remaining after the high-temperature wash procedure in general use. Using a standard method to enumerate fabric-associated bacteria, we found that soiled sheets and terry cloth items were contaminated, respectively, with 10(6) and 10(8) cfu/100 cm2 of fabric area, predominantly gram-negative rods (especially Enterobacteriaceae and Pseudomonadaceae). Staphylococcus species were the most common gram-positive organisms. A standard low-temperature washing cycle without laundry chemicals removed 3 log10 of bacteria by agitation, dilution, and drainage. When low-temperature laundry chemicals were used, 3 log10 of bacteria were killed after the bleach was added, and sheets and terry cloth items had postwash colony counts of 10(1)-10(2) cfu/100 cm2. Drying removed an additional 1-2 log10 organisms. Bacterial counts and species from low- and high-temperature washed fabrics were comparable. Low-temperature washing is therefore as effective as high-temperature washing for eliminating pathogenic bacteria from hospital laundry.

Studies of Campylobacter jejuni in patients with inflammatory bowel disease

Cultures, serology, and immunohistochemical tests for Campylobacter jejuni were performed on 74 patients with inflammatory bowel disease of various disease activity and in healthy and diseased control populations. Fecal cultures were negative in all groups tested. Antibodies to C. jejuni were assessed both by a complement fixation assay and an enzyme-linked immunosorbent assay to multiple serotypes of the organism. Antibody titers in inflammatory bowel disease patients and control populations were similar, and titers in these groups were significantly lower than in patients with acute Campylobacter enteritis. Intestinal tissues examined for Campylobacter antigens by an indirect fluorescent antibody assay were negative. These data do not etiologically implicate C. jejuni in Crohn's disease or chronic ulcerative colitis.

Identification and characterization of Campylobacter jejuni outer membrane proteins

Outer membrane proteins from isolates of Campylobacter jejuni were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Sarcosinate-insoluble membrane preparations were outer membrane enriched based on increased ketodeoxyoctonate concentrations, the presence of surface-exposed 125I-labeled proteins that were hydrophobic, and similarity to membrane vesicle (bleb) sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles. Most isolates contained a single major band with molecular weight of 41,000 to 45,000. Profiles of C. jejuni and Campylobacter coli isolates were indistinguishable, but either could be easily differentiated from Campylobacter fetus and Campylobacter faecalis. The profiles were stable for strains under a variety of growth, incubation and passage conditions. We classified 110 isolates from patients with sporadic campylobacter enteritis into nine subtypes based on differences in outer membrane sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles. Two categories accounted for 76% of the isolates. Complete concordance was observed in subtypes of strains obtained from epidemiologically related cases. Thus, comparison of the major outer membrane proteins of C. jejuni is a useful technique for investigating the transmission of this organism and may provide a basis for immunological characterization of the outer membrane proteins.

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.