Larry J. Goodman

Comparative in vitro activity of ciprofloxacin against Campylobacter spp. and other bacterial enteric pathogens.

A comparison was made of the in vitro activity of ciprofloxacin (Bay o 9867) with nine other antibiotics against isolates of Campylobacter jejuni, Salmonella spp., Shigella spp., Yersinia enterocolitica, Clostridium difficile, Vibrio spp., and Escherichia coli. Minimum inhibitory concentrations of ciprofloxacin were the lowest of any compound tested for all organisms except C. difficile.

Comparative in vitro activities of twelve antimicrobial agents against Campylobacter species.

The in vitro susceptibility of 27 Campylobacter jejuni, 31 Campylobacter coli, and 30 Campylobacter fetus subsp. fetus strains to 12 antimicrobial agents was determined. Ciprofloxacin, a new quinoline derivative, was the most active agent tested. Antimicrobial susceptibility differed among the three species tested.

Epidemiology and outcome of Clostridium difficile infection and diarrhea in HIV infected inpatients.

Clostridium difficile causes diarrhea in HIV infected patients but reports of prevalence, risk factors, and outcome vary. We studied the impact of C. difficile in 161 HIV infected inpatients admitted to Cook County Hospital. Patients with C. difficile had more hospital admissions in the previous 6 months (p =.04), spent more days in the hospital in the previous 3 months (p =.02), more often had previously received H2 blockers or treatment for Pneumocystis carinii (p <.05), and had a more frequent history of herpesvirus (p =.03) or opportunistic infections (p =.04). C. difficile associated diarrhea (CDAD) was the etiology in 32% of all study patients with diarrhea. Patients with CDAD were hospitalized for longer periods (p =.02) and received more antibiotics (p =.002). C. difficile was frequently present in our HIV infected patients, especially those with advanced HIV disease, but appeared to have little impact on morbidity or mortality.

In vitro activities of lomefloxacin and temafloxacin against pathogens causing diarrhea.

The in vitro activities of temafloxacin (A63004) and lomefloxacin (SC-47111; NY-198) were compared with those of seven other antibiotics against 146 isolates of bacterial enteric pathogens, including Campylobacter jejuni and Campylobacter coli. Ciprofloxacin was the most active drug against the Salmonella, Shigella, Yersinia, and Vibrio spp. tested. Lomefloxacin, temafloxacin, and difloxacin were the most active drugs tested against Campylobacter spp. (MIC for 90% of strains, 0.125 to 0.25 micrograms/ml).

In vitro activity of A-56268 (TE-031), a new macrolide, compared with that of erythromycin and clindamycin against selected gram-positive and gram-negative organisms.

The in vitro activity of A-56268 was determined and compared with that of erythromycin and clindamycin against a limited spectrum of 401 gram-positive and gram-negative organisms. A-56268 was quite active against erythromycin-susceptible Staphylococcus aureus, Neisseria gonorrhoeae, Listeria monocytogenes, Streptococcus pneumoniae, Streptococcus pyogenes, and group B streptococci and was moderately active against Campylobacter fetus subsp. fetus. A-56268 was consistently bactericidal only for S. pneumoniae. The activity of A-56268 was comparable to that of erythromycin against most organisms tested.

Clinical efficacy of cefotaxime in serious infections.

Thirty-five patients underwent 38 treatment courses with cefotaxime. Documented infections included 11 bacteremias, 7 cases of nosocomial pneumonia, 6 surgical wound infections, 3 bone infections, 1 biliary infection, and 1 urinary tract infection. Granulocytopenic patients with fever received 15 courses of empiric cefotaxime therapy alone; in 8 courses, no definite site of infection or pathogen was isolated. Broad-spectrum antibiotics had been administered to 23 patients before cefotaxime. Thirty-seven bacterial pathogens were isolated from 25 patients. Three such pathogens were resistant to cefotaxime and required alternative therapies. Pathogenic isolates included 13 Serratia marcescens, 12 Pseudomonas aeruginosa, 4 Escherichia coli, 2 Klebsiella pneumoniae, 2 Providencia stuartii, 1 Enterobacter cloacae, 1 Haemophilus influenzae, 1 Enterococcus, and 1 Staphylococcus aureus. Of the treatment courses, 25 of 38 resulted in a favorable response to cefotaxime, including 9 of 15 in granulocytopenic patients. Superinfection was seen in one patient. The emergence of resistance was documented in another patient. Of 15 patients with multiply resistant pathogens, 12 improved with cefotaxime. Of 12 patients with Pseudomonas aeruginosa, 6 favorably responded. Possible complications of cefotaxime were observed in 14 of 42 treatment courses. Cefotaxime is most useful in treatment of infections due to multiply resistant, gram-negative pathogens other than Pseudomonas aeruginosa.

Effects of erythromycin and ciprofloxacin on chronic fecal excretion of Campylobacter species in marmosets.

Ciprofloxacin was compared with erythromycin for the eradication of Campylobacter species that were chronically excreted in the stools of marmosets (Saguinus labiatus labiatus, Saguinus fuscicollis nigrifrons, and Saguinus fuscicollis illigeri). Stool cultures were negative within 48 h of the beginning of treatment with either agent. Within 10 days after the end of therapy, however, Campylobacter species were again isolated from the stools of six animals that had received erythromycin. During an 8-week follow-up period, no animal that had received ciprofloxacin relapsed. High levels of ciprofloxacin in the stool (mean, 49.2 micrograms/g) possibly contributed to the efficacy of this agent.

Comparative in vitro activity of A-56268 (TE-031) against gram-positive and gram-negative bacteria andChlamydia trachomatis

The in vitro activity of A-56268 (TE-031) was determined and compared with that of 13 antibiotics against 401 gram-positive and gram-negative bacteria and 11 strains ofChlamydia trachomatis.A-56268 was very active against methicillin-susceptibleStaphylococcus aureusandNeisseria gonorrhoeae,and was among the most active of the agents tested againstListeria monocytogenes,streptococci andChlamydia trachomatis.It was moderately active againstHaemophilusspp.,Vibriospp.,Campylobacter jejuniandCampylobacter fetussubsp.fetus.It was inactive against enterococci, methicillin-resistantStaphylococcus aureus,Staphylococcus epidermidis, Campylobacter coli, Salmonellaspp.,Shigellaspp. andYersinia enterocolitica.A-56268 was not consistently bactericidal or more active than erythromycin for any organism exceptChlamydia trachomatis.

Selected overview of nongynecologic surgical intra-abdominal infections: Prophylaxis and therapy

True prophylaxis of intra-abdominal nongynecologic infections is limited to elective, nonemergency surgery and is best shown in three clean-contaminated surgical procedures. All of these have an infection rate of approximately 10 to 20 percent and include all colon resection surgery, most gastric surgery, and about one third of the cholecystectomies for chronic calculous cholecystitis. Each of these three surgical procedures has a somewhat different pattern of bacterial pathogens. The most useful comparative studies of early preoperative therapy have been performed in cases of suspected appendicitis (50 percent of which usually show perforation or gangrene at the time of surgery) and penetrating abdominal wounds (80 percent of which usually enter some part of the bowel and theoretically soil the peritoneum). These procedures are usually classified as contaminated, with a 20 to 30 percent infection rate, or dirty, with a more than 30 percent infection rate, depending upon several factors. Comparative investigations of intraoperative and postoperative antibiotic therapy of established intra-abdominal infections are more difficult to obtain because of the heterogeneity of the sites, organisms, and medical and surgical therapy. The initial pathogens causing secondary peritonitis and hepatic, perirectal, diverticular, and most other types of intraperitoneal abscesses are mixed coliforms and anaerobes, with emphasis on the anaerobes. Retroperitoneal abscesses, pancreatic abscesses, and biliary tract infections are predominantly caused by coliforms. The organisms responsible for these early infections are usually community-acquired rather than more antibiotic-resistant hospital-acquired bacteria. Considering the availability of a large number of effective broad-spectrum antibacterial agents and therapeutic combinations, it has become increasingly difficult to assess the rightful place of any new prospective antimicrobial regimen unless it has quite unique characteristics. Most empiric therapy in established intra-abdominal infection studies have compared gentamicin and clindamycin, the most popular regimen in the United States over the past 15 years, with a cephalosporin, broad-spectrum penicillin, or aminoglycoside, either alone or together with clindamycin or metronidazole. Results have usually been considered similar in most studies, although in some studies, agents with limited Bacteroides fragilis activity, such as cefamandole or cefaperazone, have been considered inferior. Most new prophylactic regimens have been compared with the first-generation cephalosporins and, again, similar results have been obtained between the groups with two exceptions. Cepha

Evaluation of an outbreak of foodborne illness initiated in the emergency department

STUDY OBJECTIVES For many foodborne outbreaks, the pathogen and food vehicle never are identified. Delayed collection of epidemiologic and microbiologic information may contribute to this. We postulated that collection of this information from ill persons as they presented to the emergency department during a recent outbreak might contribute to earlier identification of the pathogen and vehicle. DESIGN At least 690 of 1,900 conventioneers developed gastrointestinal symptoms after attending a banquet. A questionnaire was developed to collect information on specific food histories, incubation periods, symptoms, physical findings, and demographics. These results were compared with results of investigations by the city and state departments of public health. SETTING The ED of Rush-Presbyterian-St Lukes Medical Center, a tertiary care university hospital in Chicago, Illinois. TYPE OF PARTICIPANTS Adults (24 men and nine women) presenting to the ED with gastrointestinal symptoms after eating a common meal. MEASUREMENTS AND MAIN RESULTS The clinical syndrome suggested an invasive pathogen. Based on this, clinical microbiology laboratory procedures were modified (isolation plates were reviewed during the evening shift). This led to early identification of the first isolates (Salmonella enteritidis) from the outbreak. The questionnaire also narrowed the vehicle to one of two foods served. Investigations by the departments of public health subsequently identified one of these, bread pudding with a raw egg based-sauce, as the vehicle. CONCLUSION Outbreak evaluations can begin in the ED or any other patient care facility. This evaluation need not always add significantly to the expenditure of time, manpower, or laboratory studies. The evaluation of even a small percentage of ill persons from a large outbreak may provide useful epidemiologic information and be particularly important in settings with limited public health resources.