Klebsiella pneumoniae isolate producing at least eight different beta-lactamases, including AmpC and KPC beta-lactamases.
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Bacterial Proteins↗
Biomedical subjects
Davise H Larone
Publications and source records attributed to Davise H Larone.
Influence of antibiotic therapy on mortality of critical surgical illness caused or complicated by infection.
BACKGROUND: Conceptually, appropriateness of antibiotic therapy includes choice of agent relative to susceptibility of pathogens as well as dosing, timing of onset, and duration of therapy, but is most commonly considered in terms of choice of antibiotic. It has been suggested that inappropriate antibiotic selection can result in increased mortality. This study was performed to elucidate the role of scheduled, rotating antibiotic therapy in defining mortality among febrile, infected surgical ICU patients. METHODS: Prospective inception-cohort study of 356 patients during their initial episode of fever (temperature > 38.2 degrees C), caused by infection diagnosed by positive cultures or direct inspection (some cases of peritonitis). Collected data included age, gender, admission APACHE III score, peak temperature, microbial isolates and susceptibility, source of infection, multiple organ dysfunction score, mortality, and several time intervals (time that cultures were collected, time from collection to antibiotic prescription, time from collection to antibiotic administration, duration of therapy). RESULTS: The mean age was 63 +/- 1 years, the mean APACHE III score was 74 +/- 2 points, the mean multiple organ dysfunction score was 8 +/- 1 points, and overall mortality was 31%. Neither the source of infection nor the specific isolate influenced mortality. Antibiotic therapy was appropriate (covered the isolates) in 94% of cases, and did not influence mortality. Duration of therapy was identical between groups (5.1 +/- 0.3 vs. 5.4 +/- 0.3 days, p = 0.61). By logistic regression (dependent variable = mortality), APACHE III score OR 1.025, 95% C.I. 1.021-1.04) and delayed antibiotic administration (30-min intervals, OR 1.021, 95% C.I. 1.003-1.038) were independent predictors of mortality. CONCLUSIONS: The use of scheduled monthly antibiotic cycling in the surgical ICU is associated with a high rate of "appropriate" antibiotic therapy, and appears to maintain or improve resistance patterns. Because antibiotic therapy was mostly appropriate for isolates, initial inappropriate therapy could not be identified as a risk factor for mortality. However, in the setting of appropriate antibiotic choice, the prompt initial administration of antibiotics appears to be crucial for survival, but neither site of infection nor specific pathogen are influential.
APACHE↗
Pseudomonas aeruginosa SoxR does not conform to the archetypal paradigm for SoxR-dependent regulation of the bacterial oxidative stress adaptive response.
SoxR is a transcriptional regulator that controls an oxidative stress response in Escherichia coli. The regulator is primarily activated by superoxide anion-dependent oxidation. Activated SoxR turns on transcription of a single gene, soxS, which encodes a transcriptional regulator that activates a regulon that includes dozens of oxidative stress response genes. SoxR homologues have been identified in many bacterial species, including the opportunistic pathogen Pseudomonas aeruginosa. However, the expected SoxR partner, SoxS, has not been found in P. aeruginosa. Thus, the primary gene target(s) of P. aeruginosa SoxR is unknown and the involvement of this regulator in the oxidative stress response of the bacterium remains unclear. We utilized transcriptome profiling to identify the P. aeruginosa SoxR regulon and constructed and characterized an unmarked P. aeruginosa DeltasoxR mutant. We provide evidence indicating that P. aeruginosa SoxR activates a six-gene regulon in response to O(2)(.-)-induced stress. The regulon includes three transcriptional units: (i) the recently identified mexGHI-ompD four-gene operon, which encodes a multidrug efflux pump system involved in quorum-sensing signal homeostasis; (ii) gene PA3718, encoding a probable efflux pump; and (iii) gene PA2274, encoding a probable monooxygenase. We also demonstrate that P. aeruginosa SoxR is not a key regulatory player in the oxidative stress response. Finally, we show that P. aeruginosa SoxR is required for virulence in a mouse model of intrapulmonary infection. These results demonstrate that the E. coli-based SoxRS paradigm does not hold in P. aeruginosa and foster new hypotheses for the possible physiological role of P. aeruginosa SoxR.
Animals↗
CHROMagar Candida as the sole primary medium for isolation of yeasts and as a source medium for the rapid-assimilation-of-trehalose test.
The chromogenic medium BBL CHROMagar Candida (CAC) was evaluated as a sole primary medium for the isolation of yeasts from clinical specimens in which yeasts are the primary concern. Additionally, the reliability of the rapid-assimilation-of-trehalose (RAT) test in yielding correct results with isolates taken from CAC was assessed. A total of 270 throat, urine, and genital (TUG) specimens were streaked onto CAC, Sabouraud dextrose agar (SDA), inhibitory mold agar (IMA), and Mycosel (MYC). A total of 69 blood culture broths that were smear positive for yeast were streaked onto CAC and SDA. A 1-h RAT test (NCCLS M35-A) was performed simultaneously on isolates from CAC and SDA. A total of 112 TUG specimens yielded yeast colonies (CAC, 111 colonies; IMA, 105; SDA, 103; MYC, 91). The 69 blood culture yeasts grew on both CAC and SDA. Mixed cultures of yeasts were detected on 11 CAC plates but were unrecognized on other media. Colonies suspected of being C. glabrata on 32 CAC plates were all RAT test positive and confirmed to be C. glabrata; of 59 colonies with various characteristics of color and morphology on CAC, none were RAT positive, and all were conventionally identified as yeasts other than C. glabrata (sensitivity and specificity, 100%). The same isolates from SDA tested for RAT produced six false negatives and no false positives (sensitivity, 81%; specificity, 100%). The results show that CAC can be used as the sole primary medium for recovery of yeasts from clinical specimens. Additionally, isolates grown on CAC yield excellent results with the RAT test utilized in this study.
Candida↗
Staphylococcus aureus express unique superantigens depending on the tissue source.
A comprehensive analysis of Staphylococcus aureus superantigen (SAG) genes was undertaken in isolates from a major hospital and compared with isolates from patients with toxic shock syndrome (TSS). Polymerase chain reaction (PCR) analysis included recently discovered SAGs. Staphylococcal enterotoxin (SE) G and SEI were uniquely expressed in genital isolates. Genital isolates were similar to TSS isolates, although the latter frequently expressed TSS toxin 1. Both had a high frequency of SEG/SEI and a high number of SAG genes per bacterium. Detection of an SAG gene by PCR correlated with positive results in functional assays for SAG activity. Levels of serum antibodies to SEG and SEI, but not to other superantigens, were higher in healthy women than in men and served as an independent measure of the higher frequency of exposure to SEG/SEI among women. Together, the data suggest a role for SEG/SEI or closely linked genes in the adaptation of S. aureus to the genital mucosa environment.
Adolescent↗
Pichia ohmeri prosthetic valve endocarditis and review of the literature.
Fungal prosthetic valve endocarditis (PVE) is a serious complication of valve replacement surgery. We report the first case of documented Pichia ohmeri PVE in an immunocompetent man who was successfully treated with valve replacement and antifungal therapy with amphotericin B.
Aged↗
Prospective, multicenter surveillance study of Candida glabrata: fluconazole and itraconazole susceptibility profiles in bloodstream, invasive, and colonizing strains and differences between isolates from three urban teaching hospitals in New York City (Candida Susceptibility Trends Study, 1998 to 1999).
Since the 1990s, the substantial increase in the rate of Candida glabrata infections has become a serious problem. As most C. glabrata infections arise from the host's endogenous microflora, the present prospective, multicenter analysis included all clinical isolates associated with colonization and with systemic and hematogenous candidiasis. Among 347 C. glabrata isolates, the overall rates of resistance to fluconazole (MIC > or = 64 micro g/ml) and itraconazole (MIC > or = 1 micro g/ml) were 10.7 and 15.2%, respectively, although for half (n = 148) of the itraconazole-susceptible isolates the MICs (0.25 to 0.5 micro g/ml) were in the susceptible-dependent upon dose range. Fluconazole resistance was more common among C. glabrata isolates obtained from centers caring for patients with cancer (MICs at which 90% of isolates are inhibited [MIC(90)s] = 32 micro g/ml) or AIDS (MIC(90)s > 64 micro g/ml) than among C. glabrata isolates from a community-based university medical center (MIC(90)s = 16 micro g/ml) (P = 0.001). Thirty-three bloodstream isolates and those obtained from other body sites had similar in vitro susceptibility profiles. The fluconazole MIC(90)s (< or =16 micro g/ml) for C. glabrata yeast isolates from the gastrointestinal tract were lower than those (> or =64 micro g/ml) for C. glabrata isolates from respiratory and urinary tract samples (P = 0.01). A similar discrepancy for itraconazole was not significant (P > 0.5). We did not observe differences in fluconazole or itraconazole susceptibility profiles among C. glabrata isolates associated with either hematogenous dissemination or colonization. The significant discrepancy in antifungal susceptibility among C. glabrata organisms isolated from hospitals in the same geographic region emphasizes the significance of periodic susceptibility surveillance programs for individual institutions, especially those providing care to patients at risk.
Antifungal Agents↗