Staphylococcal pericarditis following percutaneous transluminal coronary angioplasty.

Infectious complications occurring after percutaneous transluminal coronary angioplasty are uncommon. We are reporting a case of bacterial pericarditis developing 1 week after coronary angioplasty and stent implantation. Treatment with appropriate antibiotics and drainage of the infected pericardial effusion was followed by a protracted hospital course and eventual control of infection and discharge of the patient.

The comparative in vitro activity of clinafloxacin and other antimicrobials against vancomycin-susceptible and vancomycin-resistant enterococci.

The susceptibilities of 50 unique vancomycin-susceptible (n = 15) and vancomycin-resistant (n = 35) enterococci to 6 antimicrobials were compared. Teicoplanin was consistently the most active agent for all strains. Ampicillin and imipenem were active primarily for vancomycin-sensitive Enterococcus faecalis. Clinafloxacin and ciprofloxacin showed poorer activity compared to prior studies, suggesting that the emergence of quinolone resistance is now occurring in enterococci.

A randomized, double-blind, placebo-controlled trial of selective digestive decontamination in a medical-surgical intensive care unit.

A randomized, double-blind, placebo-controlled trial of selective decontamination of the oropharynx and gastrointestinal tract was conducted on 61 intubated patients in a medical-surgical intensive care unit (ICU) to determine the impact on nosocomial pneumonia, other infections, and emergence of colonization or infection with antibiotic-resistant bacteria. Over 8 months, 30 patients received an oral paste and solution containing polymyxin, gentamicin, and nystatin; 31 patients received a placebo paste and solution. At study entry, patients in both groups were seriously ill (mean acute physiologic score, 27.2), frequently had pulmonary infiltrates (73.8%), and were likely to be receiving systemic antibiotics (86.9%). There were no differences between study patients and control patients in these characteristics or in frequency of any nosocomial infection (50% vs. 55%), nosocomial pneumonia (27% vs. 26%), febrile days (2.3 vs. 2.0), duration of antibiotic therapy (14.0 vs. 13.4), or mortality rates (37% vs. 48%). There was no difference in infections caused by antibiotic-resistant gram-negative bacilli, although a trend towards more frequent infection with gentamicin-resistant enterococci was found for study patients. Selective decontamination did not appear to be effective in our very ill medical-surgical ICU patients, although the number of patients in our trial was sufficient to detect only a 50% or greater reduction in pneumonia rates.

Pilot trial of selective decontamination for prevention of bacterial infection in an intensive care unit.

Selective decontamination of the oropharynx and gastrointestinal tract with nonabsorbable antimicrobials and sucralfate, a stress ulcer prophylactic that maintains the normal gastric acid bacterial barrier, were compared for prevention of pneumonia in a cardiac surgery intensive care unit. Over 8 months, 51 patients received selective decontamination and 56 received sucralfate. The selective decontamination regimen included polymyxin, gentamicin, and nystatin given as an oral paste and as a solution; patients also received standard antacid or histamine2 blocker stress ulcer prophylaxis. Patients in the selective decontamination group had significantly less colonization of the oropharynx and stomach by gram-negative bacilli (12% vs. 55%, P less than .001), significantly fewer infections due to gram-negative bacilli (6% vs. 20%, P = .02), and fewer infections overall (12% vs. 27%, P = .04). There was one episode of pneumonia in the selective decontamination group and five in the sucralfate group. Mortality and length of stay did not differ between the groups, but those receiving selective decontamination had less than one-third as many days of systemic antibiotic therapy with no increase in colonization or infection with resistant gram-negative bacilli. Thus, selective decontamination appeared to reduce both extrapulmonary and pulmonary infections.

The epidemiology of Pseudomonas aeruginosa in oncology patients in a general hospital.

Pseudomonas aeruginosa colonization and infection was studied over a 6-mo period in a 36-bed mixed general medical-oncology unit. We used selective media for serial surveillance cultures on 283 patients, the environment, and personnel. Twelve percent of patients were colonized on admission and 10% acquired P. aeruginosa. Using serotyping and multilocus enzyme electrophoresis, we identified 63 genetically distinctive strains; four prevalent strains accounted for 21% of isolates. Only 5 of 33 nosocomial acquisitions were due to horizontal transmission. Nine acquisitions were linked to environmental sources (e.g., sink surfaces), which often harbored antibiotic-resistant strains but posed a risk only to oncology patients. Although significant Pseudomonas infections occurred in only 11% of colonized patients, 63% of colonized severely neutropenic patients--predominantly those who had acquired the prevalent, often environmentally linked strains--developed infections. Thus, P. aeruginosa was a significant pathogen in oncology patients; typing by multilocus enzyme electrophoresis allowed the detection of important environmental sources.

Infections with gram-negative bacilli in a cardiac surgery intensive care unit: the relative role of enterobacter.

A 7-month prospective survey for cefazolin-resistant Gram-negative bacilli in cardiac surgery patients, receiving cefazolin prophylaxis, showed that 58 (67%) of 87 were colonized with enterobacter, 37 (64%) with citrobacter, 33 (57%) with Pseudomonas aeruginosa, and seven (2%) with Serratia marcescens. About 50% of colonization occurred before cefazolin prophylaxis and was present on admission to the intensive care unit. Typing of strains showed that horizontal transmission accounted for at most 14% of carriage. Cefazolin prophylaxis (and high gastric pH) were associated with increased levels of postoperative colonization, most notably for enterobacter. About 25% of colonization with enterobacter, pseudomonas, and serratia was followed by clinical infection. Enterobacter cloacae was the most common pathogen and pneumonia the most common infection. Infections contributed to eight of 11 deaths; four of the eight involved enterobacter. Potential control measures include eliminating endogenous Gram-negative flora by gut decontamination or at least stemming the increase in level of colonization that occurred after surgery.

In vitro susceptibility of nosocomial Pseudomonas aeruginosa, enterobacteriaceae, and staphylococci to ciprofloxacin and ten other broad-spectrum antibiotics.

We determined microdilution minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) for ciprofloxacin and 10 beta-lactam and aminoglycoside antibiotics against 329 unique nosocomial isolates of Pseudomonas aeruginosa, citrobacter, enterobacter, serratia, and staphylococci. All were susceptible to ciprofloxacin, including 109 aminoglycoside-resistant gram-negative bacilli and 59 oxacillin-resistant staphylococci. Ciprofloxacin was generally 2-4 fold less active against aminoglycoside-resistant isolates than against their aminoglycoside-susceptible counterparts.

Patients' endogenous flora as the source of "nosocomial" Enterobacter in cardiac surgery.

We prospectively studied Enterobacter colonization in cardiac surgery patients receiving cefazolin prophylaxis. Fifty-eight (67%) of 87 patients became colonized, 28 by the time of admission to a Cardiac Surgery Intensive Care Unit. Enterobacter cloacae was four times more prevalent than Enterobacter aerogenes. We found increased Enterobacter colonization, after prophylaxis, in 45% of surgery patients. None of 25 control patients, who underwent coronary angioplasty and received no antibiotic prophylaxis, showed increased colonization (P = .001). Both groups had similar baseline rates of Enterobacter carriage. Typing showed 50 distinct strains of E. cloacae and 11 of E. aerogenes; 25% of patients carried greater than or equal to 2 strains simultaneously. In the nine cases of horizontal transmission, source patients were intubated for greater than or equal to 5 days and had heavy throat carriage of Enterobacter. No environmental sources of transmission were found. Clinical Enterobacter infection developed in 12 patients; at least nine of these were infected with a strain that had been isolated by surveillance culture. We conclude that Enterobacter, part of the patients' endogenous flora, becomes an important pathogen when amplified by prophylactic antibiotics and is less often transmitted horizontally.

Extended use of disposable pressure transducers. A bacteriologic evaluation.

In a prospective randomized study, contamination rates of disposable pressure transducers changed every two days (n = 81) were compared with those changed at four (n = 26) or eight days (n = 50); the mean daily incidence of contamination was 3% for each group. After four days of use, the cumulative prevalences of contamination were similar. However, after eight days, the cumulative prevalence was significantly higher in transducers used without change (6.9%) than in those changed every two days (2.9%). Gram-negative bacilli were present in 63% of contaminated transducers; over half were from the patients' own flora. The only definite transducer-related bacteremia occurred on a day of initial contamination and should have been unaffected by the interval of change. Routine use of disposable transducers can be safely extended to four days, even in a busy intensive care unit.

Antibiotic-resistant flora in nursing home patients admitted to the hospital.

To study carriage of multiply resistant gram-negative bacilli, 50 patients admitted to the hospital from nursing homes (NHs) and 50 control admissions not from NHs were matched for age and recent antibiotic use. Their antibiotic resistance patterns were similar: 20 NH patients and 14 controls had resistant strains. However, significantly more patients (64%) from NHs with large numbers of "skilled beds" had resistant bacteria than did patients from small NHs (21%) or controls (28%). Also, more patients from NHs had members of the Proteus-Providencia-Morganella group in their urine than did controls. Discriminant analysis showed that residence in NHs with large numbers of skilled beds, recent antibiotic use, and bladder dysfunction (indwelling catheter or incontinence) were independently important in predicting carriage of resistant strains in NH and control patients. Over 75% of resistant isolates were from rectal specimens, emphasizing the occult way that such strains are brought into the hospital.

Occult aminoglycoside resistance in Pseudomonas aeruginosa: epidemiology and implications for therapy and control.

The epidemiology of aminoglycoside-resistant Pseudomonas aeruginosa was evaluated in an intensive care unit (ICU) with serial surveillance cultures of throat and rectum. Bacterial population analysis performed by replica plating of primary isolation plates onto gentamicin-containing agar revealed the presence of resistant subpopulations in the initial isolates from 41 (71%) of 58 consecutive assessable patients; these isolates were stably resistant and proportionately less susceptible to other aminoglycosides. An increase in resistant subpopulations occurred during the ICU stay in 34% of 38 colonized patients cultured serially as opposed to none of 23 followed after ICU discharge (P = .0008). Isolates of P. aeruginosa from patients who received aminoglycosides in the ICU were more likely to show an increase in resistance than were isolates from other patients (55% vs. 11%; P = .005); decreasing resistance after ICU discharge followed discontinuation of antibiotic administration. ICU mortality was higher in patients with increasingly resistant subpopulations (69% vs. 16%; P = .0004). The difficulty in treating infections with P. aeruginosa and in controlling drug resistance likely relates to the common carriage of clinically undetected resistant subpopulations that emerge during therapy.

Selective survival in pentazocine and tripelennamine of Pseudomonas aeruginosa serotype O11 from drug addicts.

The growth of Pseudomonas aeruginosa, particularly serotype O11, in pentazocine and tripelennamine ("T's and Blues") was evaluated as a possible explanation for the association of deep-seated infection with this organism and abuse of these drugs. The mean reduction of growth caused by the drugs was 1,000-fold greater for 49 Pseudomonas strains from normal subjects than for 32 strains from drug addicts (4.2 vs. 1.3 logs of reduction at 2 hr, P less than .0005). A common phenotypic subset of the serotype O11 strains from drug addicts was especially resistant to the inhibitory effects. Twelve strains of Staphylococcus aureus (a frequent cause of infection in heroin, but not in pentazocine and tripelennamine, addicts) were completely inhibited by the drug combination. Dose-response curves (derived from the results of using the tablets as well as pure powders) showed that tripelennamine was responsible for the inhibitory activity, which was partially antagonized by pentazocine. We conclude that an ability of some P. aeruginosa serotype O11 strains, but not S. aureus, to survive in pentazocine and tripelennamine may explain in part a shift from S. aureus to P. aeruginosa as common pathogens of drug addicts in areas where abuse of this combination of drugs has increased.

False localization of site of endocarditis by cardiac catheterization with quantitative cultures.

The authors present a patient with relapsing Pseudomonas aeruginosa endocarditis in whom cardiac catheterization with quantitative cultures falsely localized the infection to the tricuspid valve, probably because the patient was having intermittent rather than continuous bacteremia. After catheterization the patient developed mitral insufficiency and congestive heart failure. This experience suggests that quantitative cultures during cardiac catheterization may give misleading results and that the procedure may have significant complications.

Epidemiology of endemic Pseudomonas aeruginosa: why infection control efforts have failed.

The epidemiology of Pseudomonas aeruginosa was evaluated in an intensive care unit for a period of six months by means of serial surveillance and environmental cultures. One hundred (37%) of 270 patients were noted to be colonized: 63 at the time of their admission and 37 during their stay on the unit. Colonization at the time of admission was associated with length of hospitalization before admission to the intensive care unit, age, gastrointestinal disease, and prior use of antibiotics. The strains acquired on the intensive care unit represented several different serotypes, with little clustering; the source of most strains was not found. In only 12 cases did the acquisition of P. aeruginosa appear to represent cross-infection; the use of barrier isolation could have prevented at most five of these cases. Undetected endogenous gastrointestinal carriage may have been responsible for many other apparent acquisitions. Clinical infection in association with preceding gastrointestinal colonization developed in 20 patients. The data indicate that traditional control measures aimed at the prevention of exogenous acquisition of P. aeruginosa are unlikely to have an impact on the overall incidence of infection and that efforts to prevent infection in patients who are already colonized are necessary.

Association of infection caused by Pseudomonas aeruginosa serotype O11 with intravenous abuse of pentazocine mixed with tripelennamine.

From July 1979 to June 1983, 25 of 40 intravenous drug addicts with systemic infections had Pseudomonas aeruginosa as the etiological agent; by 1982, P. aeruginosa had replaced Staphylococcus aureus as the most common pathogen. At least 21 of the 25 addicts with P. aeruginosa infection abused pentazocine mixed with tripelennamine (commonly known as T's and blues) compared with 6 of 15 addicts infected with other pathogens (P = 0.006). Of the 25 P. aeruginosa isolates, 23 were of serotype O11. Phenotypic patterns in isolates from addicts and in 22 serotype O11 control isolates from nonaddicts were determined by pyocin and electrophoretic enzyme typing, as well as by susceptibility to heavy metals and antibiotics. Of 25 isolates from addicts, 20 were identical or differed by only one marker, whereas the 22 nonaddict serotype O11 isolates were distributed among 17 distinct phenotypic patterns. We postulate that the emergence of P. aeruginosa as the major cause of deep infection in addicts is a consequence of contamination of their paraphernalia during preparation of pentazocine and tripelennamine for self-injection. The phenotypic similarity among isolates from addicts may reflect acquisition from related environmental sources and an unusual ability of certain serotype O11 strains to survive preparation of the drugs or to be invasive.

Pseudomonas in the sinks in an intensive care unit: relation to patients.

Sink drains in a medical-surgical intensive care unit (ICU) were cultured during six consecutive weeks as part of a seven month prospective study of acquisition of Pseudomonas aeruginosa by ICU patients. Isolates were typed serologically and by aminoglycoside and chlorhexidine susceptibility patterns. All 11 sinks contained multiple strains of P aeruginosa; some strains persisted for weeks while others were isolated once. Of the sink isolates 56% had high level resistance to gentamicin and tobramycin whereas none of the strains found in patients. In sink isolates chlorhexidine resistance correlated with aminoglycoside resistance and with the presence of a chlorhexidine dispenser at a sink. The sequence of recovery of phenotypically similar isolates suggested that sinks were the source of at most two acquisitions of P aeruginosa by patients during the six weeks. Our study confirms that sinks may be reservoirs for large numbers of highly resistant P aeruginosa but are rarely the source of organisms colonising patients in our ICU.