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L J Kunz

Publications and source records attributed to L J Kunz.

15 recordsLinked to original sources

Torulopsis glabrata fungemia--a clinical pathological study.

The clinical findings, pathologic features, and outcome were investigated in 46 patients in whom Torulopsis glabrata was isolated in 131 specimens of blood. Nineteen of the patients had only a single positive blood culture and no evidence of systemic yeast infection, while 27 patients had a clinically significant fungemia based upon the occurrence of 2 or more positive blood cultures, or the combination of a positive blood culture and isolation of the organism from a closed body cavity or demonstration of the yeast in tissue sections. The predisposing factors to the development of fungemia included the presence of intravenous lines, indwelling Foley catheters, antibiotics and surgery, especially when the gastrointestinal tract was involved. Only 22% of patients received either steroids or cytostatic agents. Possible portals of entry were suggested by the prior isolation of the organism from urine, sputum, wounds, and central venous catheter tips in most of the patients. Twelve of 27 patients with clinically significant fungemia were treated. The initial mode of therapy in nine patients was removal of intravenous lines because of the clinical suspicion of catheter related sepsis. Seven of the patients improved rapidly and one more after amphotericin B was subsequently administered. Amphotericin B was the initial therapy in three cases. One patient was cured while another died of an unrelated infection. Five patients were not treated although the isolation of T. glabrata had been reported; the fact that the presence of the organism was felt to be unimportant was considered to be a factor in the delay of treatment. In the remaining 10 patients the organism was isolated only after the patient had died. Division of the patients into four groups based upon whether the individuals survived, died of unrelated disease, died with potentially lethal infection, or died with T. glabrata infection significantly contributing to death, revealed a spectrum of disease, certain signs of which appeared to be of predictive value as prognostic indices of survival and severity of the infection. Seven patients with transient fungemia experienced an acute episode of high spiking fever (greater than 102.5 degrees F), rigors and/or hypotension, six of whom improved after the intravenous catheter was removed, suggesting a catheter-related sepsis. In contrast, persistent low grade fever (less than 102.5 degrees F) characterized eight of the nine patients in whom T. glabrata infection was considered either potentially lethal, or contributing significantly to death. A deteriorating clinical course with organ failure was also associated with this latter category of patients. Catheter-induced specticemia was considered in only two patients in this category. The autopsy and clinical findings in this investigation as well as reported experimental studies suggest that T. glabrata is an organism of low virulence. The patients' underlying disease (e.g., neoplasia) and coexisting bacterial infection are the most important factors responsible for death.

Adult

Resistance to gentamicin, tobramycin and amikacin among clinical isolates of bacteria.

Susceptibility to the administration of gentamicin, tobramycin and amikacin was determined for all isolates of aerobic and facultative gram-negative bacilli submitted for testing to the clinical bacteriology laboratory of the Massachusetts General Hospital between July 1, 1974, and June 30, 1976. In this 24-month period more than 46,000 isolates of bacteria were tested by the single-disc diffusion (Bauer-Kirby) method. Resistance to one or more of the aforementioned aminoglycosidic aminocyclitol antibiotics was found among 4,114 stains. Correlation with quantitative susceptibility test methods revealed that disc-diffusion methods using 10 microng discs accurately predicted resistance to gentamicin and tobramycin, but overestimated the prevalence of resistance to amikacin by 20 to 60%. Most of the gentamicin-resistant Enterobacteriaceae in this study were also cross-resistant to tobramycin but were susceptible to amikacin. Many gentamicin-resistant strains of Ps. aeruginosa were susceptible to both tobramycin and amikacin. Resistance to amikacin tended to be of relatively low magnitude (most had minimal inhibitory concentrations (MIC's) between 31 and 125 microng/ml), but organisms which were resistant to the administration of amikacin were usually resistant to the other two aminoglycosidic antibiotics as well.

Amikacin

Infections with Acinetobacter calcoaceticus (Herellea vaginicola): clinical and laboratory studies.

In a retrospective review of 53 patients, 58 episodes of infection due to Acinetobacter calcoaceticus var. anitratus (Herellea vaginicola) were studied. Although the organism is widely distributed in nature, it is of relatively low virulence since colonization is more frequently noted than infection and since most infections occur in patients subjected to the epidemiologic pressures common to nosocomial, gram-negative bacillary infection: prior antibiotic therapy; instrumentation and manipulation (e.g., endotracheal intubation, urinary bladder catheterization, arterial and venous cannulation); surgery; hospitalization, especially with residence in an intensive care unit; severe underlying disease, either systemic (e.g., chronic obstructive pulmonary disease, malignancy) or localized to the infected area (e.g., prior bacterial or aspirational pneumonia, trauma). Pneumonia was the most common infection due to A. calcoaceticus, and occurred only in patients with a tracheostomy or endotracheal tube in place. In over half the 25 patients, more than one lobe was involved and bronchopneumonia was the usual roentgenographic appearance. Cavitation (2 patients) and empyema formation (3 patients) were uncommon. The severity of acinetobacter pneumonia is reflected in the high mortality rate (44% overall, with a 36% mortality rate due primarily to infection). Tracheobronchitis due to A. calcoaceticus was less severe than pneumonia since no patients died primarily as a result of the infection. Urinary tract infections occurred in five patients, none of whom were ill and none of whom died. Urinary bladder catheterization was thought to be responsible for infection in three patients, and in at least four of the five patients infection was restricted to the lower tract. Wound infections were noted in six patients who had undergone surgery and were related to the presence of foreign bodies in the operative site in five of the patients. Surgical debridement and/or drainage of the infected area was the primary therapeutic measure employed in most cases. Only one patient died and this was a result of noninfectious causes. Skin infection due to A. calcoaceticus was seen in two patients, one of whom exhibited fulminant, fatal cellulitis and septicemia in the setting of pancytopenia. All nine patients with acinetobacter septicemia had received antecedent antibiotic therapy, and in all cases intravenous catheters were in place at the time bacteremia occurred. Clinically, seven of the nine patients were in shock. The mortality rate was 44% overall, with a 22% mortality rate due to infection. Although septicemia was thought to be "line-related" in five of the nine patients, serious post-bacteremic complications developed in three patients: prosthetic valve endocarditis, suppurative thrombophlebitis and subhepatic abscess.

Acinetobacter

Resistance to six aminoglycosidic aminocyclitol antibiotics among enterococci: prevalence, evolution, and relationship to synergism with penicillin.

Two hundred and three recent clinical isolates of enterococci were tested for susceptibility to streptomycin, kanamycin, amikacin, gentamicin, sisomicin, and tobramycin. Depending upon the source of the isolate, 36 to 54% of the enterococci demonstrated high-level resistance (minimal inhibitory concentration, >2,000 mug/ml) to streptomycin, 16 to 49% to kanamycin, and 0 to 14% to amikacin. None of the strains was highly resistant to gentamicin, sisomicin, or tobramycin. A comparison with isolates of enterococci obtained in 1968 revealed that there has been a decrease in prevalence of high-level resistance among organisms isolated from wound cultures in 1976. However, no decrease in resistance to streptomycin or kanamycin was demonstrated among blood or urine isolates. Penicillin, combined with gentamicin, sisomicin, or tobramycin, was synergistic against all 10 strains of Streptococcus faecalis subjected to formal testing. For streptomycin and kanamycin, the presence or absence of synergism with penicillin correlated with the absence or presence of high-level aminoglycoside resistance. High-level resistance to amikacin was seen in only 1 of the 10 strains. Nonetheless, combinations of penicillin plus amikacin failed to produce synergistic killing against 6 of the 10 strains. Indeed, the combination was synergistic only against those four strains that were susceptible to high levels of kanamycin.

Aminoglycosides

Microbiologic basis for the rational use of prophylactic antibiotics.

Appropriate use of antibiotics is enhanced by the effective application of data on antimicrobial susceptibility. A number of methods are currently available for routine determination of susceptibilities, including agar dilution, broth dilution, agar diffusion, and several semiautomated methods. If susceptibility testing is properly done, it can serve as the basis for the generation of statistical data of use to the clinician. Periodically updated tables detailing the antimicrobial susceptibilities of commonly isolated organisms enable the physician to make appropriate choices of antibiotics for prophylaxis and for the initial treatment of serious infections, before the susceptibilities of the infecting organisms are known. With computer assistance, it is possible to use susceptibility data for quality control and for more sophisticated epidemiologic purposes. For the past several years, we have studied a number of potential uses of computer-generated data at the Massachusetts General Hospital. Several of these applications, especially as they might relate to the prophylactic use of antibiotics, are discussed in this paper.

Anaerobiosis

Computerization in microbiology.

Computerization of the clinical microbiology laboratory is finally coming of age. Operations and functions easily adapted from other clinical laboratories have already been implemented in the microbiology laboratory, e.g., fiscal, clerical, and other administrative housekeeping chores. Similarly, storage, retrieval, and analysis of banks of data easily collected and filed have also been successfully accomplished in microbiology for several years. The more challenging problems of computerization still deserve and require the attention of microbiologists. These problems lie in the smooth sequential formulation and transmission of clinical microbiological test results from the laboratory to clinical records; the manipulation of relevant data by the computer prospectively for the detection and prediction of nosocomial infections or miniepidemics; and the development of programed lessons and examinations for computerized instruction, retraining, and examination of technologists and other individuals interested in microbiology.

Clinical Laboratory Techniques

Effects of penicillin and lysozyme on the immunofluorescent and precipitin reactivity of group D streptococci.

Damage to the cell wall by growth in the presence of penicillin or by treatment with lysozyme enhanced the immunofluorescent (fluorescent antibody, FA) reactivity to group D streptococci. The optimum concentration and time of treatment with lysozyme varied inversely with the initial FA reactivity of the strain. Speciation of the organisms by a series of biochemical and physiologic tests suggested that the differences in initial FA reactivity were species-related. Thus, S. faecalis strains were the most FA-reactive and most sensitive to lysozyme. S. faecium strains were less FA-reactive and lysozyme-sensitive. S. bovis strains proved to be least FA-sensitive and were most resistant to lysozyme. Treatment with lysozyme was also effective in preparing extracts of group D antigen from all three species for Lancefield grouping by the precipitin test. The lysozyme extracts, moreover, produced much stronger reactions than those made from comparable volumes of cells by the methods of Lancefield or of Rantz and Randall.

Antibodies, Heterophile

Emergence of gentamicin-resistant bacteria: experience with tobramycin therapy of infections due to gentamicin-resistant organisms.

A computerized system for testing and surveillance of bacterial susceptibility to antibiotics was used in monitoring the emergence of gentamicin-resistant strains of aerobic and facultative gram-negative bacilli at Massachusetts General Hospital since the release of gentamicin for clinical use in 1971. During the period studied, there was a significant increase in the prevalence of gentamicin-resistant bacteria, particularly among Pseudomonas, Acinetobacter (Herellea), and Proteus and, more recently, among Enterobacter and Klebsiella. Most gentamicin-resistant strains of Pseudomonas aeruginosa and Acinetobacter calcoaceticus var. anitratum (Herellea varginicola) retained susceptibility to tobramycin. Of the other gentamicin-resistant organisms, most were also resistant to tobramycin. Twelve patients with infections caused by gentamicin-resistant organisms were treated with tobramycin. All 12 patients were seriously ill, and all but one had failed to respond to previous therapy with gentamicin. Nine patients responded favorably to tobramycin, and six were cured. P. aeruginosa and A. calcoaceticus var. anitratum were most frequently the infecting organisms in these patients. Patients received tobramycin for three to 42 days; no significant drug-related toxicity was noted. These results emphasize the increasing clinical importance of gentamicin-resistant bacteria and suggest that tobramycin may be effective for treatment of some, but not all, infections caused by gentamicin-resistant bacteria.

Acinetobacter

Identification of streptococci: serogrouping by immunofluorescence.

This paper deals with the fluorescent antibody (FA) method for identifying six commonly occuring and two rare groups of streptococci by using commercially prepared (Difco) conjugates. We have shown that group-specific FA produced frequent cross-reactions with heterologous groups of organisms. These reactions varied with different strains of the same serogroup. Nonetheless, there was distinct overall patterns in the intensity and appearance of the homologous and heterologous reactions. When monitored by the precipitin test with Rantz and Randall extracts, these patterns led to the correct identification of 90 to 100% of specimens of serogroup A, B, C, and G streptococci. Many members of groups D and F also showed distinctive reaction patterns. However, there was a significant number of strains of both groups D and F that either failed to strain or stained poorly with the homologous conjugate. As a result, the identification of these serogroups by FA was less reliable.

Cross Reactions

Identification of streptococci: use of lysozyme and Streptomyces albus filtrate in the preparation of extracts for Lancefield grouping.

A combination of lysozyme and Streptomyces albus filtrate has been shown effective in extracting group-specific antigen for all commonly occurring serologically groupable streptococci. A prospective comparison of this method with that of Rantz and Randall (1955) for grouping 761 clinical isolates has confirmed its accuracy, which in our hands exceeded that of the latter more complicated method of serogrouping. Its rapidity and simplicity and the relatively low cost of the reagents involved make it practical for routine use in clinical bacteriology laboratories.

Cell-Free System