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Biomedical subjects

D R Schaberg

Publications and source records attributed to D R Schaberg.

At least 19 recordsLinked to original sources
PubMed1992

Increasing resistance of enterococci to ciprofloxacin.

We determined that resistance to ciprofloxacin has emerged in enterococci over the last 5 years in our hospital, mainly in strains demonstrating the phenotype of high-level gentamicin resistance. All high-level-gentamicin-resistant isolates from 1985 and 1986 were susceptible, whereas 24% of isolates from 1989 and 1990 were resistant to ciprofloxacin. Plasmid and genomic DNA typing showed at least six unique strains exhibiting resistance, but one type accounted for 80% of recent resistant isolates, suggesting a role for cross infection in the emergence of resistance.

Ciprofloxacin↗
PubMed1992

Endoscopic detection and therapy of colonic actinomycosis.

Abdominal actinomycosis is a disease that is difficult to diagnose nonoperatively. Usual manifestations are abscesses and draining sinus tracts. Treatment is typically surgical and requires prolonged intravenous antibiotics. Presented is a patient who underwent surveillance colonoscopy after resection for colon carcinoma. Diagnosis of colonic actinomycosis and subsequent resolution was demonstrated endoscopically after lengthy oral penicillin therapy (2 g/day for 1 yr). This case documents that resection may not be necessary to effect cure of abdominal actinomycosis.

Actinomycosis↗
PubMed1991

Major trends in the microbial etiology of nosocomial infection.

To determine trends in the microbial etiology of nosocomial infections in the 1980s, surveillance data on the microbiology of documented nosocomial infection reported to the National Nosocomial Infections Surveillance System and from the University of Michigan Hospital were analyzed. Antimicrobial susceptibility data on selected pathogens from both sources were also reviewed. Overall, Escherichia coli decreased from 23% of infections in 1980 to 16% in 1986-1989, Klebsiella pneumoniae dropped from 7% to 5%, whereas coagulase negative staphylococci increased from 4% to 9% and Candida albicans increased from 2% to 5%. Staphylococcus aureus, Pseudomonas aeruginosa, Enterobacter species and enterococci had minor increases, but antimicrobial resistant strains for these pathogens as well as coagulase-negative staphylococci were seen more frequently. In contrast to the 1970s, major shifts in the etiology of nosocomial infection have occurred in the decade of the 1980s. Taken as a whole, the shifts are away from more easily treated pathogens toward more resistant pathogens with fewer options for therapy. These shifts underscore the continued need for prevention and control to accompany new developments in therapy.

Bacteria↗
PubMed1991

Methicillin-resistant Staphylococcus aureus: colonization and infection in a long-term care facility.

OBJECTIVE: To assess methicillin-resistant Staphylococcus aureus (MRSA) colonization, transmission, and infection over a 1-year period in a long-term care facility with endemic MRSA. DESIGN: Monthly surveillance for MRSA colonization of nares, perineum, rectum, and wounds. SETTING: Long-term care facility attached to an acute care Veterans Affairs medical center. PATIENTS: All 341 patients in the facility had monthly surveillance cultures for 1 year. OUTCOME MEASUREMENTS: Colonization and infection with MRSA. MAIN RESULTS: The monthly MRSA colonization rate was 23% +/- 1.0%; colonization occurred most commonly in the nares and wounds. Poor functional status was associated with MRSA colonization. Most patients (65%) never acquired MRSA; 25% of patients were already colonized at admission to the facility or at the start of the study, and only 10% of newly admitted patients acquired MRSA while in the facility. These latter patients acquired several different strains in a pattern of acquisition similar to that generally seen within the facility. In the course of 1 year, only nine patients who acquired MRSA had a roommate with the same phage type; no clustering was evident, and none of these patients developed infection. Nine other patients (3%) developed MRSA infection; five of these patients required hospitalization, but none died as a result of infection. CONCLUSIONS: In the long-term care facility in which our study took place, MRSA was endemic, and the infection rate was low. In such settings, the cost effectiveness of aggressive management of MRSA (widespread screening for MRSA and eradication with antimicrobial agents) needs to be assessed.

Aged↗
PubMed1991

Effect of controlled hemorrhage on tissue and serum cefazolin clearance.

Effects of blood loss on tissue and serum antibiotic levels were investigated in 30 New Zealand white rabbits. Studies were conducted over a 3.5-hr period after intravenous administration of cefazolin, 30 mg/kg, in control animals (Groups I and IV, n = 5 each) and animals having 50% (Groups II and V, n = 5 each) or 100% (Groups III and VI, n = 5 each) of their blood volume removed and replaced with either Ringer's solution (Groups I, II, and III) or rabbit whole blood (Groups IV, V, and VI) sufficient to maintain central venous pressures at baseline levels. Periodic samples of retroperitoneal fat, iliac artery, and serum were assayed for cefazolin concentration by disc diffusion. Decreased tissue antibiotic levels were observed in animals undergoing 100% blood replacement (Groups III and VI) compared to controls (Groups I and IV) in both fat (P less than or equal to 0.01) and artery (P less than or equal to 0.01) at 90 min. Decreased antibiotic serum half-life accompanying hemorrhage existed when comparing Group II to I (P less than or equal to 0.05), Group III to I (P less than or equal to 0.01), and Group IV to V (P less than or equal to 0.01). The increased antibiotic clearance related to blood loss in this study justifies reassessment of intraoperative dosing intervals. More frequent dosing may be required to maintain stable tissue and serum antibiotic levels during substantial operative hemorrhage.

Animals↗
PubMed1990

Neisseria mucosa endocarditis.

A case of Neisseria mucosa tricuspid valve endocarditis in an intravenous drug abuser is described. The patient was treated initially with intravenous penicillin G followed by oral penicillin VK but relapsed. He was cured after 4 weeks of combined therapy with penicillin G and gentamicin. In vitro synergy studies performed on the patient's and two other isolates revealed synergy in all three. Thus, combination therapy is recommended for treatment of recalcitrant cases of bacterial endocarditis caused by N. mucosa.

Adult↗
PubMed1990

Efficacy of ampicillin versus trimethoprim-sulfamethoxazole in a mouse model of lethal enterococcal peritonitis.

Lethal enterococcal peritonitis in mice was used to compare trimethoprim-sulfamethoxazole (TMP-SMX) therapy with ampicillin therapy. Peritoneal fluid showed a 10(3)-CFU decrease in enterococci with ampicillin compared with TMP-SMX. Mortality of the untreated mice was 100%, compared with 40% for ampicillin and 95% for TMP-SMX, despite adequately measured levels in serum and peritoneal fluid.

Ampicillin↗
PubMed1990

Increasing resistance of Staphylococcus aureus to ciprofloxacin.

We demonstrated the marked emergence of resistance to ciprofloxacin among Staphylococcus arueus strains isolated at the Ann Arbor Veterans Administration Medical Center. All S. aureus isolates tested from 1984 to 1985 were susceptible, whereas 55.1% of methicillin-resistant and 2.5% of methicillin-susceptible strains from 1989 had high-level resistance to ciprofloxacin.

Ciprofloxacin↗
PubMed1990

Artery, periarterial adipose tissue, and blood microbiology during vascular reconstructive surgery: perioperative and early postoperative observations.

The presence and clinical significance of bacteria in the arterial wall, periarterial adipose tissue, and blood samples acquired during elective vascular operations were assessed in this study. Specimens were obtained from a random series of 84 patients (56 men, 28 women) undergoing 75 primary and 9 secondary arterial reconstructions. Operations performed most frequently included abdominal aortic aneurysmectomy (42), aortofemoral bypass reconstruction (15), and lower extremity bypass surgery for occlusive disease (7). Perioperative antibiotics were administered to all but one patient. A sample of artery, adjacent adipose tissue, and blood were obtained for microbial analysis during the vascular anastomosis or arteriotomy. This yielded a total of 152 artery, 139 adipose tissue, and 129 blood samples for study. Each specimen was divided and placed in blood agar plates, thioglycolate broth, and brain-heart infusion broth. Tissues yielding growth of the same organism(s) in two or more different media were considered positive for the presence of bacteria. Bacteria were present in at least one of the three tissues studied in 32/84 patients (38%). The frequency of positive cultures in primary (29/75, 39%) and secondary procedures (3/9, 33%) were similar. One positive culture site occurred in 26/32 (81%) patients, two positive culture sites existed in 5/32 (16%) patients, and three positive sites were found in 1/22 (3%) patients. Eighteen individual artery (18/152, 12%) and 19 adipose tissue samples (19/139, 14%) harbored bacteria, whereas only two blood cultures were positive (2/129, 2%). Organisms identified included coagulase-negative staphylococci (71%), gamma-streptococci (7%), diphtheroids (7%), Micrococcus (5%), alpha-streptococci (5%), Staphylococcus aureus (2%), and Pseudomonas picketti (2%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1988

Enterococcal infections: an increasing problem in hospitalized patients.

We studied 157 episodes of infection or colonization with enterococci in 122 patients over a six-month period. One hundred twelve episodes (71.3%) occurred in patients over age 60 years. The most common sites for isolation of enterococci were the urinary tract, and bone and soft tissue. Nosocomial acquisition of enterococci occurred in 74.7% of all infections, and an additional 21% of episodes occurred in patients who had been transferred from another hospital or were regularly seen in the clinic. The overall mortality was 19.6%; 71.4% of those with bacteremia died. Enterococci appear to be significant pathogens, especially in older men in veterans' acute care hospitals and nursing home care units.

Aged↗
PubMed1988

Epidemiology of Clostridium difficile colonization in newborns: results using a bacteriophage and bacteriocin typing system.

We used a typing system based on bacteriophage and bacteriocin susceptibility to study the epidemiology of Clostridium difficile colonization of newborn infants. C. difficile was found in the stools of 30 (16.0%) of 187 infants who were screened. Increased length of stay in the nursery (P less than .001) and delivery by cesarian section (P less than .001) were associated with higher rates of colonization. The isolates initially detected from the environment and the infants were strain B1811-1700. Strain B1537/Cld7 became the predominant isolate obtained from the infants; positive cultures were also obtained from the environment and the hands of personnel who worked in the nursery and had strain B1537/Cld7. Our results suggest that the infants acquired C. difficile through transfer from the hands of hospital staff.

Bacterial Proteins↗
PubMed1988

Enterococcal superinfection in patients treated with ciprofloxacin.

Two patients developed serious enterococcal superinfection following therapy with intravenous ciprofloxacin. The strains causing bacteraemia were susceptible to low concentrations of ciprofloxacin when tested at a standard inoculum. However, at an inoculum of 1 X 10(7) cfu/ml they were resistant to high concentrations of ciprofloxacin. Our data suggest that ciprofloxacin should not be used to treat patients with serious enterococcal infection and that patients treated with ciprofloxacin should be monitored carefully for the development of enterococcal superinfection.

Adult↗
PubMed1988

Acquisition of Clostridium difficile from the hospital environment.

An outbreak of antibiotic-associated colitis that occurred on a ward of a Michigan hospital during February-April, 1984, was studied by bacteriophage-bacteriocin typing. Stools from the seven involved patients yielded Clostridium difficile isolates of types B1537 or Cld7;B1537. C. difficile was recovered from 31.4% of environmental cultures obtained on the ward, and the majority of isolates were types B1537 or Cld7;B1537. When the ward was disinfected with unbuffered hypochlorite (500 parts per million (ppm) available chlorine), surface contamination decreased to 21% of initial levels and the outbreak subsequently ended. Phosphate buffered hypochlorite (1,600 ppm available chlorine, pH 7.6) was even more effective; its use resulted in a 98% reduction in surface contamination. These findings suggest that environmental contamination with C. difficile is important in the epidemiology of antibiotic-associated colitis, and that hypochlorite is effective in eliminating C. difficile from the hospital environment.

Clostridium↗
PubMed1988

The pathogenesis of spinal epidural abscess: microangiographic studies in an experimental model.

An experimental model of spinal epidural abscess was developed in rabbits by injecting Staphylococcus aureus into the posterior thoracolumbar epidural space. This model has been shown to reproduce the neurological, bacteriological, and radiological aspects of the human disease. In this study, the effect of the infectious epidural mass on the vasculature of the spinal cord in paraplegic rabbits was studied using microangiographic techniques. The normal vascular anatomy of the rabbit spinal cord was defined in control experiments. Vascular proliferation was demonstrated in the epidural space surrounding the abscesses. Anterior and paired posterior spinal arteries remained patent in paraplegic rabbits with mild or moderate spinal cord compression and in some cases of severe compression. In animals with severe compression, the anterior epidural venous plexus remained patent, but the dorsal spinal vein was occluded. Occlusion of perforating arteries occurred only with extreme spinal cord compression. These data indicate that the initial neurological deficit associated with experimental spinal epidural abscess is not due to vascular thrombosis.

Abscess↗
PubMed1987

Fever in hospitalized patients. With special reference to the medical service.

Fever (oral temperature of 38 degrees C or more on two or more consecutive days) during the hospital stay of 4,065 patients admitted to Grady Memorial Hospital during an 11-week period was studied. At least one episode of fever occurred in 1,194 patients (29 percent). Rates of fever were highest on medical and surgical services. Review of 341 episodes of fever in 302 patients on the medical service identified a single potential cause in 56 percent. Multiple factors were present in 26 percent, and no potential causes were found in 18 percent. Of 390 factors identified, 44 percent were community-acquired infections, 9 percent were nosocomial infections, 20 percent possibly involved infection, and 26 percent were noninfectious processes. Fever is a frequent finding in hospitalized patients. Both infectious and noninfectious processes play important roles. Determining the cause of fever is complicated by the multiplicity of possible causes.

Cross Infection↗
PubMed1987

High-level aminoglycoside-resistant enterococci. Colonization of nursing home and acute care hospital patients.

Enterococci with high-level resistance (HLR) to gentamicin sulfate and other aminoglycosides have emerged as pathogens in recent years. More than half of all current isolates of enterococci at the Ann Arbor (Mich) Veterans Administration (VA) Medical Center are HLR strains. We determined the rate of colonization with HLR enterococci in patients in the acute care hospital, the attached nursing home, and a private nursing home. We also studied the factors related to colonization and the molecular relatedness of strains of HLR enterococci in these settings. In the VA facilities, 47.4% of patients in the nursing home and 36.1% of patients in the acute care hospital were colonized, compared with a 4.3% colonization rate in the private nursing home. Intravenous or Foley catheters and bedridden status were associated with colonization in the acute care setting; the need for advanced nursing care and prior antibiotic therapy were associated with colonization in the nursing home. Environmental surfaces were contaminated with HLR enterococci in both VA settings. Plasmid analysis of HLR strains revealed identity between both patient and environmental strains in the nursing home care unit and the acute care hospital. Nursing home patients, with their high rate of colonization with HLR enterococci and their frequent movement into the acute care hospital, may play a role as a reservoir for subsequent transmission of HLR enterococci.

Cross Infection↗