Anti-Campylobacter, anti-aerobic, and anti-oxidative effects of roselle calyx extract and protocatechuic acid in ground beef.

The inhibitory effect of roselle calyx extract and protocatechuic acid against susceptible and antibiotic-resistant Campylobacter jejuni, C. coli and C. fetus in agar plate and ground beef was examined. The minimal inhibitory concentrations of roselle calyx extract and protocatechuic acid against susceptible and antibiotic-resistant Campylobacter species were in the range of 96-152 and 20-44 microg/ml, respectively. Temperature treatments from 25 to 100 degrees C did not affect the anti-Campylobacter activity of protocatechuic acid. In ground beef stored at 15 degrees C for 6 days, roselle calyx extract and protocatechuic acid inhibited the survival and growth of aerobes, and susceptible and antibiotic-resistant Campylobacter species, in which protocatechuic acid exhibited dose-dependent effect. Both roselle calyx extract and protocatechuic acid decreased lipid oxidation levels in ground beef, in which protocatechuic acid also exhibited dose-dependent effect. The addition of roselle calyx extract or protocatechuic acid did not affect cooking loss, pH value, sensory attributes and content of fat, protein and moisture of beef samples during storage at 4 degrees C for 15 days. These data support that roselle calyx extract and protocatechuic acid may be used for muscle foods to prevent contamination from Campylobacter and aerobes, as well as delay lipid oxidation.

Development of quinolone-resistant Campylobacter fetus bacteremia in human immunodeficiency virus-infected patients.

Campylobacter fetus subspecies fetus has been recognized as a cause of systemic illness in immunocompromised hosts, including relapsing bacteremia in human immunodeficiency virus (HIV)-infected patients. Acquired resistance to quinolone therapy, while reported for a variety of bacteria, including Campylobacter jejuni, has not been previously documented for C. fetus. Two cases of quinolone-resistant C. fetus bacteremia were detected in HIV-infected patients. Cloning and nucleotide sequencing of the C. fetus gyrA gene in the 2 resistant isolates demonstrated a G-to-T change that led to an Asp-to-Tyr amino acid substitution at a critical residue frequently associated with quinolone resistance. In addition, comparison of the pre- and posttreatment isolates from 1 patient documented outer membrane protein changes temporally linked with the development of resistance. Relapsing C. fetus infections in quinolone-treated HIV-infected patients may be associated with the acquisition of resistance to these agents, and this resistance may be multifactorial.

[Evaluation of antimicrobial drugs and atmospheres for the isolation of Campylobacter fetus subspp. from the bovine genital tract]. / Evaluación de drogas antimicrobianas y atmósferas para el aislamiento de Campylobacter fetus subspp. del tracto genital bovino.

Growth of 3 reference bovine C. fetus strains in media with and without antibiotics and bacteriostats active against the most common contaminant bacteria in the bovine genital tract was evaluated. In addition, 2 regional bovine C. fetus strains and 1 reference C. sputorum biovar bubulus strain were used in some experiments. Reference strain C. fetus subsp. venerealis was completely inhibited by polymyxin (> or = 0.25 IU/ml) whereas the other C. fetus strains were not inhibited. In Shepler's medium supplemented with rifampicin (10 micrograms/ml) subsp. fetus, was the only one to grow. When rifampicin was used at 5 micrograms/ml together with a reduced dose of the other Shepler's antibiotics, especially polymyxin B (0.85 IU/ml), subsp. venerealis was able to grow; nevertheless even at such a reduced dose, rifampicin was inhibitory for the biotype intermedius. It was demonstrated that triclosan (Irgasan) could be very useful at < or = 10 micrograms/ml in media with added blood, < or = 6 micrograms/ml in brucella broth and < or = 3 micrograms/ml in Mueller-Hinton broth for isolation of all subspecies of C. fetus. The sensitivity of C. fetus to 5-fluorouracil was variable: subsp. fetus was resistant (up to 800 micrograms/ml) whereas subspp. venerealis and biotype intermedius grew slowly or sometimes did not grow at all in concentrations of 6.25 micrograms/ml onwards. Fosfomycin was inhibitory to all C. fetus strains at > or = 50 micrograms/ml. C. sputorum biovar. bubulus was less inhibited than C. fetus with triclosan grew up to more than 100 micrograms/ml, with 5-fluorouracil up to 100 micrograms/ml and with fosfomycin up to 50 micrograms/ml. Growth of C. fetus subspp. was compared in different microaerophilic atmospheres contained in anaerobic jars (Oxoid HP 11) without palladium catalyzer. Growth with nitrogen or hydrogen was similar. When jars were replaced by 15 x 13 cm cylindrical cans without valves or gas measurement devices only pure hydrogen supported satisfactory growth of all C. fetus subspp. and C. sputorum biovar. bubulus strains. The candle system, a commercial nitrogen rich gas mixture and pure carbonic anhydride prepared in these cans failed to enable these strains to grow. C. fetus subsp. fetus was more aero-tolerant than subsp. venerealis and its biotype intermedius and was able to grow, although very weakly, with only carbonic anhydride added to an aerobic atmosphere. The growth obtained using a commercial gas generating microaerophilic kit (Oxoid BR-56) was comparable to the one achieved with the hydrogen rich atmosphere prepared in our laboratory.

Bismuth subsalicylate in the prevention of colonization of infant mice with Campylobacter jejuni.

Infant mice were used for the evaluation of the efficacy of bismuth subsalicylate (BSS) in the prevention of the growth of Campylobacter jejuni in the intestine. The MIC90 of ten C. jejuni strains was 900 micrograms/ml. Of three dosage regimens tested, continuous treatment before and after the bacterial challenge, mimicking the way BSS is used in the prevention of traveller's diarrhoea, was the most effective. Growth inhibition was dose dependent; the high dose of 2000 micrograms per day was more effective than 300 micrograms per day. After cessation of treatment, campylobacter counts increased to the same level as in the control animals.

Efficacies of erythromycin and chloramphenicol in extinguishing fecal shedding of Campylobacter jejuni in dogs.

Oral treatment regimens of erythromycin stearate and chloramphenicol were evaluated in naturally infected laboratory colony dogs for their efficacies in extinguishing fecal shedding of Campylobacter jejuni. Of the 25 Campylobacter-infected English Foxhounds in the study, 9 were assigned to erythromycin treatment, 9 to chloramphenicol treatment, and 7 to no treatment. Antimicrobials were administered for 12 days. All of the dogs that received erythromycin stearate ceased shedding C jejuni by the fourth day of treatment and remained negative throughout the treatment period. Chloramphenicol was associated with a reduction in shedding from 100% to 57% by the ninth day of treatment. Within 9 days of the discontinuation of antimicrobial treatment, C jejuni was isolated from all chloramphenicol-treated dogs and 89% erythromycin-treated dogs.

Early treatment of Campylobacter jejuni enteritis.

The bacteriologic and clinical effects of early antibiotic treatment of Campylobacter jejuni enteritis were studied. Erythromycin rapidly eliminated C. jejuni from stools, whereas trimethoprim-sulfamethoxazole did not. Despite its bacteriologic effectiveness, erythromycin did not reduce the duration or severity of diarrhea, abdominal pain, or other symptoms.

Response of Campylobacter jejuni to combinations of ferrous sulphate and cadmium chloride.

On Mueller Hinton (MH) agar, Campylobacter jejuni showed 20.0 and 30.9 mm zones of inhibition surrounding discs impregnated with 2.5 and 20 micrograms CdCl2 respectively. The minimal inhibitory concentration (MIC) ranged from 0.64 to 3.2 micrograms CdCl2/ml of MH agar for four C. jejuni strains. In the presence of 23 micrograms FeSO4/ml of MH the MIC increased to a range of 1.5-5.4 micrograms CdCl2/ml of MH. Moreover, the numbers of colonies present on MH supplemented with FeSO4 were greater than on MH without iron. The growth response of C. jejuni in the presence of 0.025% (w/v) FeSO4 in MH broth was increased about 10,000 fold in three of four strains when compared with the growth in unsupplemented MH broth. Zones of inhibition surrounding 20 micrograms discs of CdCl, were 50.6 and 24.4 mm on MH and Campy-BAP media respectively, with cells grown on MH. These results suggest that the blood-containing medium 'neutralized' the biocidal influence of the CdCl2. In comparison, C. jejuni inoculum from fluid thioglycollate (FT) medium showed smaller zones of inhibition. These decreased from 34.9 mm on MH agar to 19.6 mm on Campy-BAP agar, suggesting that components in the FT growth medium ameliorated the toxic influence of CdCl2. Atomic absorption spectroscopy analysis indicated mean values (mg/100 g dry weight) of selected metals bound by C. jejuni as: Cu, 10.4; Mg, 146; Na, 2385; Fe, 45.1; Zn, 13.0; and K, 172.

Ciprofloxacin in the treatment of acute bacterial diarrhea: a double blind study.

In a double-blind, randomized, placebo-controlled trial 50 adult patients with acute diarrhea received either 500 mg ciprofloxacin b.i.d. or a placebo for five days. Results were evaluated in 21 patients in the ciprofloxacin group (10 with Salmonella spp., 11 with Campylobacter jejuni) and 25 patients in the placebo group (16 with Salmonella spp., 5 with Campylobacter jejuni, 4 with Shigella spp.). The duration of fever in patients treated with ciprofloxacin was 1.5 days versus 2.3 days in the placebo group; the difference was not statistically significant. The duration of diarrhea in the ciprofloxacin group was 1.4 days versus 2.6 days in the placebo group (p less than 0.01); the corresponding figures in patients with salmonellosis were 1.6 versus 3.2 (p = 0.01). In the ciprofloxacin group all stool cultures became negative 48 h after start of treatment and remained negative during the follow-up period of three weeks. In the placebo group only one of the 25 patients had negative stool cultures during therapy and only seven after the treatment period (p less than 0.001). Ciprofloxacin was very well tolerated and was found to be a safe compound without major adverse effects.

Heat injury and repair in Campylobacter jejuni.

A procedure for detecting and quantitating heat injury in Campylobacter jejuni was developed. Washed cells of C. jejuni A7455 were heated in potassium phosphate buffer (0.1 M, pH 7.3) at 46 degrees C. Samples were plated on brucella agar supplemented with Na2S2O3, FeSO4 X 7H2O, and sodium pyruvate and on a medium containing brilliant green, bile, Na2S2O3, FeSO4 X 7H2O, and sodium pyruvate. Colonies were counted after 5 days of incubation at 37 degrees C in an atmosphere containing 5% O2, 10% CO2, and 85% N2. After 45 min at 46 degrees C, there was virtually no killing and ca. two log cycles of injury. Cells grown at 42 degrees C were more susceptible to injury than cells grown at 37 degrees C. The addition to brucella agar supplemented with Na2S2O3, FeSO4 X 7H2O, and sodium pyruvate of three different antibiotic mixtures used in the isolation of C. jejuni from foods or clinical specimens did not prevent recovery of heat-injured C. jejuni. Cells lost 260 nm of absorbing materials during heat injury. The addition of 5% NaCl or 40% sucrose to the heating buffer prevented leakage but did not prevent injury. Of the additional salts, sugars, and amino acids tested for protection, only NH4Cl, KCl, and LiCl2 prevented injury. Heat-injured C. jejuni repaired (regained dye and bile tolerance) in brucella broth supplemented with Na2S2O3, FeSO4 X 7H2O, and sodium pyruvate within 4 h. Increasing the NaCl in this medium to 1.25% inhibited repair, and increasing it to 2% was lethal. Heat-injured C. jejuni will repair at 42 degrees C but not at 5 degrees C.

Procedure for increased recovery of Campylobacter jejuni from inoculated unpasteurized milk.

Different treatments were applied to Campylobacter jejuni-inoculated unpasteurized milk to identify means of enhancing the survival of the organism in refrigerated (4 degrees C) samples. The greatest survival occurred in milk supplemented with 0.01% sodium bisulfite and held under an atmosphere of 100% nitrogen (bisulfite-nitrogen), in most instances allowing isolation of C. jejuni from highly contaminated milk 15 or more days longer than from unsupplemented milk held in air (21% oxygen). Although a larger amount of Campylobacter was consistently recovered from milk treated with bisulfite-nitrogen, similar isolation rates (qualitative) resulted from milk stored in air and supplemented with 0.01% sodium bisulfite and 0.15% sodium thioglycolate when analyzed within 12 days after sampling. Milk samples to be transported and assayed at a later date would best be held refrigerated (4 degrees C) and supplemented with 0.01% sodium bisulfite and either 0.15% sodium thioglycolate or an atmosphere of 100% nitrogen.

A modified broth-disk antibiotic susceptibility test for Campylobacter jejuni.

A broth-disk method for determining the antibiotic susceptibility of Campylobacter species was studied. The broth-disk method used to test anaerobes was modified for testing the antibiotic susceptibility of Campylobacter jejuni in an aerobic atmosphere. The basal medium of the test consisted of Brucella broth with 0.13% agar and contained a ferrous iron, sodium pyruvate, sodium bisufite supplement. Antibiotic disks were added to the tubed medium to approximate the minimal inhibitory concentration (MIC) breakpoint values for susceptibility. The antibiotic susceptibilities of 29 strains of Campylobacter jejuni to seven antibiotics were tested by the broth-disk method and the results compared with the MIC values determined by agar dilution. The broth-disk results were reproducible and agreed with approximately 90-100% of the MIC determinations. This broth-disk method appears to be a reliable, simple, and inexpensive method for testing antibiotic susceptibility of Campylobacter species.