Antimicrobial susceptibilities of Campylobacter jejuni and Campylobacter coli isolated in Sweden: a 10-year follow-up report

Recurrent Campylobacter jejuni bacteremia in a patient with hypogammaglobulinemia: A case report

RATIONALE

Although some cases of recurrent bacteremia due to Campylobacter jejuni have been reported in immunocompromised patients, antibiotic treatment strategies to eradicate C. jejuni and prevent recurrent infections in immunocompromised patients have not been established. Authors' experience of such rare cases should be shared for improving patients' outcomes.

PATIENT CONCERNS

An 18-year-old boy with hypogammaglobulinemia, who received intravenous immunoglobulin replacement therapy every 3 weeks, was admitted to hospital repeatedly due to recurrent diarrhea and cellulitis of the leg.

DIAGNOSES

The patient was admitted 6 times, and among them, C. jejuni was isolated from blood cultures 4 times and stool cultures 2 times.

INTERVENTIONS

The patient experienced recurrent C. jejuni enteritis and bacteremia 5 times despite macrolide therapy. Doxycycline was administered for 3 months after the fifth admission.

OUTCOMES

Ten months after the completion of doxycycline therapy for 3 months, C. jejuni enteritis relapsed; however, since then, recurrent infection has not occurred for 10 months.

LESSONS

Immunocompromised patients can experience recurrent C. jejuni infection despite prolonged antibiotic therapy. Further studies to establish appropriate antibiotic therapy for eradicating colonized C. jejuni and preventing recurrent infection are needed.

Antimicrobial resistance and antimicrobial use associated with laboratory-confirmed cases of Campylobacter infection in two health units in Ontario

AIM

A population-based study was conducted over a two-year period in the Perth District (PD) and Wellington-Dufferin-Guelph (WDG) health units in Ontario to document antimicrobial resistance and antimicrobial use associated with clinical cases of laboratory-confirmed campylobacteriosis.

METHODS

Etest (bioMérieux SA, France) was used to determine the minimum inhibitory concentration of amoxicillin/clavulanic acid, ampicillin, chloramphenicol, ciprofloxacin (CIP), clindamycin, erythromycin (ERY), gentamicin, nalidixic acid and tetracycline. Data regarding antimicrobial use were collected from 250 cases.

RESULTS

Of the 250 cases, 165 (65.7%) reported staying home or being hospitalized due to campylobacteriosis. Fifty-four per cent of cases (135 of 249) reported taking antimicrobials to treat campylobacteriosis. In 115 cases (51.1%), fecal culture results were not used for treatment decisions because they were not available before the initiation of antimicrobial treatment and/or they were not available before the cessation of symptoms. Of the 250 cases, 124 (49.6%) had available Campylobacter isolates, of which 66 (53.2%) were resistant to at least one of the antimicrobials tested. No resistance to ampicillin, chloramphenicol or gentamicin was found in these isolates. Six isolates (4.8%) were resistant to CIP. Two isolates (1.6%) were resistant to ERY; however, no isolates were resistant to both CIP and ERY.

CONCLUSION

Prudent use practices should be promoted among physicians to reduce the use of antimicrobials for the treatment of gastroenteritis in general and campylobacteriosis in particular, as well as to minimize the future development of resistance to these antimicrobials in Campylobacter species.

Prevalence, antibiograms, and transferable tet(O) plasmid of Campylobacter jejuni and Campylobacter coli isolated from raw chicken, pork, and human clinical cases in Korea

The antibiotic resistance patterns and prevalence of the transferable tet(O) plasmid were investigated in Campylobacter jejuni and Campylobacter coli isolates from raw chicken, pork, and humans with clinical campylobacteriosis. A total of 180 C. jejuni and C. coli isolates were identified, and the prevalence rates of C. jejuni and C. coli in raw chicken samples were 83% (83 of 100) and 73% (73 of 100), respectively. Twelve percent (6 of 50) and 10% (5 of 50) of pork samples were contaminated with C. jejuni and C. coli, respectively. Disk diffusion susceptibility testing revealed that the most frequently detected resistance was to tetracycline (92.2%), followed by nalidixic acid (75.6%), ciprofloxacin (65.0%), azithromycin (41.5%), ampicillin (33.3%), and streptomycin (26.1%). Of the C. jejuni and C. coli isolates, 65.7% (n=109) contained plasmids carrying the tet(O) gene. Six C. jejuni isolates and two C. coli isolates with high-level resistance to tetracycline (MIC=256 microg/ml) harbored the tet(O) plasmid, which is transferable to other C. jejuni and C. coli isolates. These results demonstrate the presence of an interspecies transferable plasmid containing the tet(O) gene and a high prevalence of antibiotic resistance in Korean Campylobacter isolates and provide an understanding of the antibiotic resistance distribution among Campylobacter species in Korea.

A survey of fluoroquinolone resistance in Escherichia coli and thermophilic Campylobacter spp. on poultry and pig farms in Great Britain

AIMS

To estimate the proportions of farms on which broilers, turkeys and pigs were shedding fluoroquinolone (FQ)-resistant Escherichia coli or Campylobacter spp. near to slaughter.

METHODS AND RESULTS

Freshly voided faeces were collected on 89 poultry and 108 pig farms and cultured with media containing 1.0 mg l(-1) ciprofloxacin. Studies demonstrated the specificity of this sensitive method, and both poultry and pig sampling yielded FQ-resistant E. coli on 60% of farms. FQ-resistant Campylobacter spp. were found on around 22% of poultry and 75% of pig farms. The majority of resistant isolates of Campylobacter (89%) and E. coli (96%) tested had minimum inhibitory concentrations for ciprofloxacin of > or =8 mg l(-1). The proportion of resistant E. coli and Campylobacter organisms within samples varied widely.

CONCLUSIONS

FQ resistance is commonly present among two enteric bacterial genera prevalent on pig and poultry farms, although the low proportion of resistant organisms in many cases requires a sensitive detection technique.

SIGNIFICANCE AND IMPACT OF THE STUDY

FQ-resistant bacteria with zoonotic potential appear to be present on a high proportion of UK pig and poultry farms. The risk this poses to consumers relative to other causes of FQ-resistant human infections remains to be clarified.

Antimicrobial resistance of 114 porcine isolates of Campylobacter coli

Campylobacter species were isolated from 24 pig farms in 10 different regions of Korea, and were assayed with regard to their susceptibility to eight antimicrobial agents. A total of 114 Campylobacter isolates from 572 intestinal samples were all identified as C. coli via both classical methods and molecular methods, including 16S rDNA sequence analysis and polymerase chain reactions (PCR) using specific primer sets for the hippuricase gene and the aspartokinase gene, designed to differentiate C. coli from C. jejuni. Minimal inhibitory concentrations of seven antimicrobial agents were determined via agar dilution: the MIC(90)s were 64 microg/ml for ampicillin, 8 microg/ml for chloramphenicol, 64 microg/ml for ciprofloxacin, 16 microg/ml for enrofloxacin, >or=128 microg/ml for erythromycin, >or=128 microg/ml for gentamicin, and >or=128 microg/ml for tetracycline. The proportion of isolates resistant to each antimicrobial agent was as follows: 28.9% for ampicillin, 2.6% for chloramphenicol, 84.2% for ciprofloxacin, 83.3% for enrofloxacin, 46.5% for erythromycin, 20.2% for gentamicin, and 56.1% for tetracycline. All 114 isolates were found to be resistant to at least one antimicrobial agent, and 61 isolates (53.5%) were found to be multi-drug resistant (resistant to more than three antimicrobial agents in different classes).

International guidelines for the treatment of community-acquired pneumonia in adults: the role of macrolides

The significance of community-acquired pneumonia (CAP) has led to the publication of guidelines from numerous international organisations. Because the macrolide class of antimicrobials is active against most of the key pathogens associated with CAP, agents from this class are commonly included in recommendations from these guidelines. However, there are differences among the various guidelines concerning the positioning of the macrolides for empirical therapy. An important factor concerning the use of macrolides for CAP is the emergence of resistance of Streptococcus pneumoniae over the past decade. The rate of S. pneumoniae resistance to macrolides ranges from 4 to 70% of strains in worldwide surveillance studies. The most common mechanisms of resistance include methylation of a ribosomal target encoded by the erm gene and efflux of the macrolides by a cell membrane protein transporter, encoded by the mef gene. S. pneumoniae strains with the mef gene are resistant at a lower level (with minimum inhibitory concentration [MIC] values generally 1-16 microg/ml) than erm resistant strains; and it is possible that such strains may be inhibited if sufficiently high levels of macrolide can be obtained at the infected site. Currently mef-associated resistance predominates in North America, whereas erm predominates in Europe. Until recently, reports of failure of treatment of CAP with macrolides has been rare, particularly for patients with low-risk for drug-resistant strains. However, since 2000, several patients treated with an oral macrolide who have subsequently required admission to the hospital for macrolide-resistant S. pneumoniae (MRSP) bacteraemia have been reported in the literature. Major issues, which are fundamental to the use of the macrolides as recommended in the various guidelines, include the importance of providing therapy for 'atypical' pathogens and the clinical significance of MRSP. Presently, the macrolides are more prominently recommended in the North American guidelines than in other parts of the world. The difference in the emphasis placed on the importance of the atypical pathogens as well as the expression of MRSP in North America compared with Europe partly explains this variance.

Comparison of broth microdilution, E Test, and agar dilution methods for antibiotic susceptibility testing of Campylobacter jejuni and Campylobacter coli

A standardized broth microdilution method was compared to the E test and an agar dilution method for the antimicrobial susceptibility testing of Campylobacter jejuni and C. coli isolates. A group of 47 human clinical isolates, 37 isolates from retail poultry, and 29 isolates from living turkeys (total, 113 isolates) was included in the study. These encompassed 92 C. jejuni and 21 C. coli strains. The MICs of six antimicrobial agents were determined by the broth microdilution and E test methods, and the strains of human origin were additionally tested by the agar dilution method. In general, broth microdilution MICs agreed within 1 log(2) MIC increment with 90.0% of E test results and 78.7% of agar dilution test results. The agar dilution method gave much lower gentamicin MICs than the broth microdilution method, but the data were significantly (P < 0.01) correlated and there was 100% agreement in the sensitivities and specificities in the comparison of the tests. The broth microdilution method had the highest sensitivity for analysis of the susceptibilities of Campylobacter to nalidixic acid and trimethoprim-sulfamethoxazole. The MICs of ciprofloxacin and erythromycin complied numerically by all three methods. The classification of the results and the correlation of the data demonstrated a high degree of agreement. All methods were equally suitable for the testing of the sensitivity of Campylobacter to tetracycline. Thus, the broth microdilution method appears to be an easy and reliable method for determination of the MICs of antibiotics for C. jejuni and C. coli, and it may offer an interesting alternative to MIC determination by the agar dilution technique or the E test.

Quinolone and macrolide resistance in Campylobacter jejuni and C. coli: resistance mechanisms and trends in human isolates

The incidence of human Campylobacter jejuni and C. coli infections has increased markedly in many parts of the world in the last decade as has the number of quinolone-resistant and, to a lesser extent, macrolide-resistant Campylobacter strains causing infections. We review macrolide and quinolone resistance in Campylobacter and track resistance trends in human clinical isolates in relation to use of these agents in food animals. Susceptibility data suggest that erythromycin and other macrolides should remain the drugs of choice in most regions, with systematic surveillance and control measures maintained, but fluoroquinolones may now be of limited use in the empiric treatment of Campylobacter infections in many regions.

Antibiotic resistance in Campylobacter strains isolated from animals, foods, and humans in Spain in 1997-1998

Colonization by Campylobacter strains was investigated in human, broiler, and pig fecal samples from 1997-1998, as well as in foods of animal origin, and antibiotic susceptibility testing was carried out for these strains. Campylobacter strains were isolated in the foods of animal origin (55 of 101 samples; 54.4%), intestinal samples from broilers (85 of 105; 81%), and pigs (40 of 45; 88.9%). A total of 641 Campylobacter strains were isolated from 8,636 human fecal samples of clinical origin (7.4%). Campylobacter jejuni was the most frequently isolated species from broilers (81%) and humans (84%), and Campylobacter coli was most frequently isolated from pigs (100%). An extremely high frequency of ciprofloxacin resistance was detected among Campylobacter strains, particularly those isolated from broilers and pigs (99%), with a slightly lower result for humans (72%); cross-resistance with nalidixic acid was almost always observed. A higher frequency of resistance to erythromycin (81.1%), ampicillin (65.7%), gentamicin (22.2%), and amikacin (21.6%) was detected in C. coli strains isolated from pigs compared to those isolated from humans (34.5, 29.3, 8.6, and 0%, respectively). A low frequency of erythromycin resistance was found in C. jejuni or C. coli isolated from broilers. A greater resistance to ampicillin and gentamicin (47.4 and 11.9%, respectively) was detected in C. jejuni isolated from broilers than in human strains (38 and 0.4%, respectively). Beta-lactamase production was found in 81% of the Campylobacter strains tested, although 44% of them were characterized as ampicillin susceptible. The increasing rates of Campylobacter resistance make advisable a more conservative policy for the use of antibiotics in farm animals.

Integronlike structures in Campylobacter spp. of human and animal origin

Resistance to antimicrobial agents used to treat severe Campylobacter spp. gastroenteritis is increasing worldwide. We assessed the antimicrobial resistance patterns of Campylobacter spp. isolates of human and animal origin. More than half (n = 32) were resistant to sulphonamide, a feature known to be associated with the presence of integrons. Analysis of these integrons will further our understanding of Campylobacter spp. epidemiology.

The effects of antibiotic usage in food animals on the development of antimicrobial resistance of importance for humans in Campylobacter and Escherichia coli

Modern food animal production depends on use of large amounts of antibiotics for disease control. This provides favourable conditions for the spread and persistence of antimicrobial-resistant zoonotic bacteria such as Campylobacter and E. coli O157. The occurrence of antimicrobial resistance to antimicrobials used in human therapy is increasing in human pathogenic Campylobacter and E. coli from animals. There is an urgent need to implement strategies for prudent use of antibiotics in food animal production to prevent further increases in the occurrence of antimicrobial resistance in food-borne human pathogenic bacteria such as Campylobacter and E. coli.

Rapid emergence of high-level resistance to quinolones in Campylobacter jejuni associated with mutational changes in gyrA and parC

Quinolone resistance in clinical isolates of Campylobacter jejuni in Sweden increased more than 20-fold at the beginning of the 1990s. Resistance to 125 microgram of ciprofloxacin per ml in clinical isolates was associated with chromosomal mutations in C. jejuni leading to a Thr-86-Ile substitution in the gyrA product and a Arg-139-Gln substitution in the parC product.

Purulent pleurisy caused by Campylobacter lari

An 80-year-old debilitated patient developed purulent pleurisy caused by a Campylobacter lari isolate. The patient underwent surgical drainage and received antibiotic therapy with amoxicillin/clavulanic acid and ofloxacin. Antibiotic susceptibility data showed that the isolate was fully sensitive to clarithromycin, tetracycline, aminoglycosides. and ciprofloxacin. Imipenem and amoxicillin plus clavulanic acid were the most active beta-lactam agents.

Antimicrobial susceptibility patterns of thermophilic Campylobacter spp. from humans, pigs, cattle, and broilers in Denmark

The MICs of 16 antimicrobial agents were determined for 202 Campylobacter jejuni isolates, 123 Campylobacter coli isolates, and 6 Campylobacter lari isolates from humans and food animals in Denmark. The C. jejuni isolates originated from humans (75), broilers (95), cattle (29), and pigs (3); the C. coli isolates originated from humans (7), broilers (17), and pigs (99); and the C. lari isolates originated from broilers (5) and cattle (1). All isolates were susceptible to apramycin, neomycin, and gentamicin. Only a few C. jejuni isolates were resistant to one or more antimicrobial agents. Resistance to tetracycline was more common among C. jejuni isolates from humans (11%) than among C. jejuni isolates from animals (0 to 2%). More resistance to streptomycin was found among C. jejuni isolates from cattle (10%) than among those from humans (4%) or broilers (1%). A greater proportion of C. coli than of C. jejuni isolates were resistant to the other antimicrobial agents tested. Isolates were in most cases either coresistant to tylosin, spiramycin, and erythromycin or susceptible to all three antibiotics. More macrolide-resistant isolates were observed among C. coli isolates from swine (79%) than among C. coli isolates from broilers (18%) and humans (14%). Twenty-four percent of C. coli isolates from pigs were resistant to enrofloxacin, whereas 29% of C. coli isolates from humans and none from broilers were resistant. More resistance to streptomycin was observed among C. coli isolates from swine (48%) than among C. coli isolates from broilers (6%) or humans (0%). The six C. lari isolates were susceptible to all antimicrobial agents except ampicillin and nalidixic acid. This study showed that antimicrobial resistance was found only at relatively low frequencies among C. jejuni and C. lari isolates. Among C. coli isolates, especially from swine, there was a high level of resistance to macrolides and streptomycin. Furthermore, this study showed differences in the resistance to antimicrobial agents among Campylobacter isolates of different origins.

Indwelling device-related bacteremia caused by serum-susceptible Campylobacter coli

Two isolates of serum-susceptible Campylobacter coli were recovered in a 7-day interval from blood from a patient with hepatocellular carcinoma and liver cirrhosis whose peritoneal-caval (Denver's) shunt malfunctioned. Identical random amplified polymorphic DNA fingerprints, cellular fatty acid chromatograms, and antibiograms of the two isolates indicate that C. coli has the ability to cause catheter-related bacteremia following its colonization of the catheter.

Disc susceptibility testing for thermomphilic campylobacters

The minimum inhibitory concentrations (MICs) and zone diameters around NCCLS strength discs of 100 clinical isolates of thermophilic Campylobacter species, including 79 strains of Campylobacter jejuni subsp. jejuni, 19 of C. coli and two of C. lari, plus three type strains of these species, were determined for erythromycin, clindamycin, nalidixic acid, norfloxacin, ciprofloxacin, ampicillin, piperacillin, cephalothin, ceftriaxone, chloramphenicol, gentamicin and tetracycline. Using error-rate bounded analysis and adjustment of MIC breakpoints to fit natural populations, tentative interpretive zone diameter criteria were set for each of the antimicrobials. Application of these criteria showed that resistance to quinolones was not detected in species other than C. lari. Two strains of C. jejuni subsp. jejuni were susceptible to cephalothin. The type strain of C. lari was susceptible to erythromycin and resistant to clindamycin. Full resistance to erythromycin, chloramphenicol or gentamicin was not found in any strain, while nine strains were resistant to tetracycline. This disc method should provide a simple approach to resistance detection for surveillance or routine testing of invasive isolates.

Sequential development of resistance to fluoroquinolones and erythromycin in an isolate of Campylobacter jejuni

A severe episode of Campylobacter jejuni gastroenteritis in a patient with HIV infection was treated with ciprofloxacin and, because of therapeutic failure, subsequently with roxithromycin. After treatment, C. jejuni was again isolated from feces and shown to be resistant to both drugs. We present molecular evidence of the sequential development of both types of resistance in the patient isolate. To our knowledge, this is the first case with documented evidence showing sequential emergence of resistance to fluoroquinolones and erythromycin in a strain of C. jejuni during treatment.

Antibiotic susceptibility of campylobacter isolates from sewage and poultry abattoir drain water

In this study, the in vitro susceptibility of 209 campylobacter strains to the quinolones nalidixic acid, flumequine, ciprofloxacin, enrofloxacin, and to ampicillin, tetracycline and erythromycin was tested by the disk diffusion method. The strains were isolated from poultry abattoir effluent (DWA) and two sewage purification plants (SPA and SPB). Sewage purification plant SPA received mixed sewage, including that from a poultry abattoir, whereas SPB did not receive sewage from any meat-processing industry. The quinolone resistance of the DWA isolates ranged from 28% for enrofloxacin to 50% for nalidixic acid. The strains isolated from the sewage purification plants were more susceptible to the quinolones with a range of 11-18% quinolone resistance for SPB isolates to 17-33% quinolone resistance for SPA isolates. The susceptibility criteria as recommended by National Committee Clinical Laboratory Standards (USA) cannot readily be employed for campylobacter isolates. This investigation shows that the resistance of campylobacter bacteria is highest in the plant receiving sewage from a poultry slaughterhouse. Monitoring of antibiotic resistance of aquatic Campylobacter spp. is important, as surface waters are recognized as possible sources of infection.

Bactericidal properties of Campylobacter jejuni-specific immunoglobulin M antibodies in commercial immunoglobulin preparations

Campylobacter jejuni is one of the most common enterocolitis-causing microorganisms worldwide. It is of particular importance in immunodeficient patients, who frequently are prone to develop extraintestinal manifestations. Since these cases respond poorly to antibiotic treatment, a supportive immunomodulating therapy including the administration of C. jejuni-specific immunoglobulins would be desirable. In the present study, nine commercial immunoglobulin preparations for intravenous use were tested for the presence of C. jejuni lipopolysaccharide (LPS)- and outer membrane protein (OMP)-specific antibodies by using immunoblot and enzyme-linked immunosorbent assay techniques. The immunoglobulin G (IgG) antibody reactivities against these antigens were comparable in eight of nine tested immunoglobulin preparations. Only in one preparation were C. jejuni OMP- and LPS-specific IgM antibodies found. In this preparation the immunoblot test revealed a strong reactivity against both flagellin and a major OMP. Moreover, all immunoglobulin preparations recognized OMPs of C. jejuni serotypes Lior 4, 9, 11, and 29 equally strongly, while the reactivity to an anti-Lior 36 isolate was less marked. Furthermore, the bactericidal properties of three immunoglobulin preparations were tested by means of chemiluminescence signaling in and bacterial killing by human polymorphonuclear leukocytes (PMNL). The results show that the IgM preparation enhanced Campylobacter-triggered chemiluminescence signaling in PMNL as well as killing of C. jejuni by PMNL, while the other immunoglobulin preparations did not do so. These results suggest that the administration of immunoglobulin preparations containing C. jejuni-specific IgM antibodies would be beneficial for patients with severe C. jejuni infections.

Temperature-dependent membrane fatty acid and cell physiology changes in coccoid forms of Campylobacter jejuni

The effect of temperature and the availability of nutrients on the transition of spiral Campylobacter jejuni cells to coccoid forms was investigated. Ageing of spiral C. jejuni cells in either nutrient-poor or nutrient-rich environments resulted in the formation of nonculturable coccoid cells at 4, 12, and 25 degrees C after different periods, with the cells incubated at 4 degrees C in nutrient-deficient media remaining culturable the longest. To study the phenomenon, ATP levels, protein profiles, and fatty acid compositions were monitored under conditions where the transition from spiral to coccoid cells occurred. During storage, the levels of intracellular ATP were highest in cells incubated at low temperatures (4 and 12 degrees C) and remained constant after a small initial decrease. During the transformation from spiral to coccoid forms, no alteration in protein profiles could be detected; indeed, inhibition of protein synthesis by chloramphenicol did not influence the transition. Furthermore, DNA damage by gamma irradiation had no effect on the process. Membrane fatty acid composition of cocci formed at low temperatures was found to be almost identical to that of spiral cells, whereas that of cocci formed at 25 degrees C was clearly different. Combining these results, it is concluded that the formation of cocci is not an active process. However, distinctions between cocci formed at different temperatures were observed. Cocci formed at 4 degrees C show characteristics comparable to those of spirals, and these cocci may well play a role in the contamination cycle of C. jejuni.(ABSTRACT TRUNCATED AT 250 WORDS)

Susceptibilities of fluoroquinolone-resistant strains of Campylobacter jejuni to 11 oral antimicrobial agents

The resistance of Campylobacter jejuni strains to the fluoroquinolones is increasingly frequent, and in our area it reaches nearly 50%. We studied the susceptibilities of 60 of these strains to 11 oral antibiotics. All strains except one were susceptible to the macrolides tested, with azithromycin being the most active agent tested. Of the rest of the antibiotics studied, amoxicillin-clavulanic acid, clindamycin, and fosfomycin displayed good in vitro activities. Knowledge of the susceptibilities of these microorganisms to a varied group of oral agents is necessary in view of the appearance of multiresistant strains, such as those included in our series.

A survey of Campylobacter bacteremia in three Danish counties, 1989 to 1994

Over a 5-year period (April 1989 to March 1994) bacteremia caused by Campylobacter species was diagnosed in 15 patients in a population of 1.3 million in three counties in Jutland province, Denmark. The incidence was 0.2/100,000/year and the ratio of blood to fecal isolates, was 0.008. Campylobacter coli and Campylobacter jejuni accounted for 6 cases each, Campylobacter fetus for 2, and in 1 case the species diagnosis was uncertain. Seven patients were males and 8 females; median age was 42 (range 15-90) years. 11 patients had underlying disorders, including immunological, neoplastic and vascular disease. In a 67-year-old man a Starr-Edwards prosthesis of the aortic valve was probably infected by C. fetus, as recurrent bacteremia resolved following valve replacement. Eight patients had pyrexia and diarrhea, whereas 7 had pyrexia with only slight intestinal discomfort or none at all. In 4 patients the bacteremia was associated with cutaneous cellulitis or vasculitis. 14 of 15 patients survived. Campylobacter bacteremia seems to be more common in Denmark than hitherto thought.

Increase of ciprofloxacin resistance in Campylobacter species in Styria, Austria

Salmonella spp. and thermophilic Campylobacter spp. are the most important diarrhea-causing pathogens in the area investigated in Styria, Austria. The isolation rate of Campylobacter in the more than 62,000 stool specimens investigated in the six-year period between 1988 and 1993 ranged between 1.90% in 1988 and 3.58% in 1991. The testing of susceptibility to nalidixic acid has been an usual characteristic for species identification. Nalidixic acid-resistant strains were rare in 1988-1990, but in the summer of 1991, we found an increasing number of these isolates. At the same time, we learnt about the increasing use of enrofloxacin in veterinary medicine, especially in the poultry industry, and therefore we started routine testing of Campylobacter spp. susceptibility to ciprofloxacin in 1992. In 1992, the resistance rate to ciprofloxacin was already 16.9%, rising to 22.1% in 1993.

Evolution of susceptibilities of Campylobacter spp. to quinolones and macrolides

Erythromycin, new macrolides, and quinolones are alternatives for the treatment of Campylobacter infections. Concerns related to the emergence of resistance to both groups of drugs have been raised. We studied the evolution of antimicrobial susceptibilities of 275 clinical isolates of microorganisms of the genus Campylobacter isolated in our institution during a 5-year period (1988 to 1992). The microorganisms studied were C. jejuni (n = 230), C. coli (n = 42), and C. fetus (n = 3). The overall resistance rates (determined by the agar dilution method and the recommendations of the National Committee for Clinical Laboratory Standards) were as follows: erythromycin, 2.3%; clarithromycin, 2.3%; azithromycin, 1.9%; ciprofloxacin, 28.5%; norfloxacin, 31%; ofloxacin, 26.3%; and nalidixic acid, 36.8%. The evolution of resistance (percent resistance in 1988 versus percent resistance in 1992) was as follows: erythromycin, 2.6 versus 3.1; clarithromycin, 2.6 versus 3.1; azithromycin, 2.6 versus 3.1; ciprofloxacin, 0 versus 49.5; norfloxacin, 2.6 versus 55.5; ofloxacin, 0 versus 45.6; nalidixic acid, 2.6 versus 56.8. Our data show stable macrolide activity against Campylobacter spp. and the rapid development of quinolone resistance over the last 5 years.

Susceptibilities of beta-lactamase-positive and -negative strains of Campylobacter coli to beta-lactam agents

The percentages of susceptibility of 28 strains of Campylobacter coli to beta-lactam agents were 96% for amoxicillin and ampicillin, 57% for ticarcillin, 4% for cefoxitin and cefuroxime, 61% for cefotaxime, and 11% for ceftazidime. None of the strains were susceptible to penicillin G, piperacillin, cefazolin, cephalothin, cefamandole, and cefoperazone. All strains were susceptible to imipenem and ciprofloxacin, and 21% were susceptible to erythromycin. A beta-lactamase was detected in 68% of the strains by cefinase disks and by the nitrocefin method. The beta-lactamase-positive strains were significantly less susceptible to amoxicillin, ampicillin, and ticarcillin than the beta-lactamase-negative strains (P < or = 0.003). Clavulanic acid (0.25 microgram/ml) but not sulbactam and tazobactam (2 micrograms/ml) lowered to susceptible levels the amoxicillin and ampicillin MICs of the only strain of C. coli resistant to amoxicillin, ampicillin, and ticarcillin.