ABSTRACT
BACKGROUND: Severe pneumonia (SP) is a clinically critical acute disease which has a higher mortality rate among infectious diseases. In this report, a rare case of severe pneumonia with severely high lactic acid (up to 24 mmol/L) and relatively normal pH was analyzed. METHODS: The case was discussed from different angles including acid-base balance disorder, the use of extractor-poreal membrane oxygenation (ECMO), dialysis treatment, circulatory disturbance, and inspection methodology. RESULTS: Hypoxia and dissolution of muscles caused by circulatory disorders may be the cause of the abnormal increase of lactate in this case; while the relatively normal pH may be caused by the dialysis treatment. CONCLUSIONS: Such a high blood gas lactic acid value is extremely rare, and this increase is not due to the limitations of the test method. High lactic acid may not result in the significant decrease of pH when the patient receives continuous systemic treatment.
Subject(s)
Lactic Acid , Pneumonia , Humans , Hypoxia , Pneumonia/diagnosis , Pneumonia/therapyABSTRACT
Acinetobacter baumannii has emerged as a globally important nosocomial pathogen characterized by an increased multi-drug resistance (MDR), leaving limited options for treating its infection. To identify novel antibacterial compounds with activity against clinical isolates of A. baumannii, we performed high-throughput screening against a chemical library of 42,944 compounds using nonpathogenic Escherichia coli MG1655 and identified 55 hit compounds. The antibacterial activities of 30 pure compounds were determined against MDR clinical isolates of A. baumannii obtained from Los Angeles County hospitals. Two isothiazolones identified, 5-chloro-2-(4-chloro-3-methylphenyl)-4-methyl-3(2H)-isothiazolone (Compound 6) and 5-chloro-2-(4-chlorophenyl)-4-methyl-3(2H)-isothiazolone (Compound 7), possess novel structure and exhibited consistent, potent and cidal activity against all 46 MDR A. baumannii clinical isolates and reference strains. Additionally, structure-activity relationship analysis involving several additional isothiazolones supports the link between a chloro-group on the heterocyclic ring or a fused benzene ring and the cidal activity. Attempts to obtain isothiazolone resistant mutants failed, consistent with the rapid cidal action and indicative of a complex mechanism of action. While cytotoxicity was observed with Compound 7, it had a therapeutic index value of 28 suggesting future therapeutic potential. Our results indicate that high-throughput screening of compound libraries followed by in vitro biological evaluations is a viable approach for the discovery of novel antibacterial agents to contribute in the fight against MDR bacterial pathogens.
Subject(s)
Acinetobacter baumannii/drug effects , Anti-Bacterial Agents/pharmacology , High-Throughput Screening Assays/methods , Thiazoles/pharmacology , Acinetobacter Infections/drug therapy , Acinetobacter Infections/microbiology , Acinetobacter baumannii/isolation & purification , Cell Line, Tumor , Cross Infection/drug therapy , Cross Infection/microbiology , Drug Resistance, Multiple, Bacterial , Escherichia coli/drug effects , Hep G2 Cells , Humans , Microbial Sensitivity Tests , Structure-Activity RelationshipABSTRACT
Acinetobacter spp. increasingly have been wreaking havoc in hospitals and communities worldwide. Although much has been reported regarding Acinetobacter isolates responsible for nosocomial infections, little is known about these organisms in correctional facilities. In this study, we performed species identification, examined the antibiotic resistance profiles, and determined the mechanisms of resistance and clonal relationships of 123 Acinetobacter isolates obtained from inmates of 20 California correctional facilities (CCFs). We found that 57.7% of the isolates belong to A. baumannii, followed by isolates of Acinetobacter genomic species 3 (gen. sp. 3; 23.6%) and of Acinetobacter gen. sp. 13TU (10.6%). Multidrug-resistant (MDR) CCF isolates were found in only six CCFs. Additionally, DNA sequences of gyrA and parC genes were consistent with fluoroquinolone (FQ) susceptibility phenotypes. Furthermore, the presence of class 1 integrons was detected in 15 CCF isolates, all of which are MDR. Integron-associated gene cassettes encode several aminoglycoside modification enzymes, which correlate with most of the aminoglycoside-resistant phenotypes. Antimicrobial susceptibility testing in the presence of Phe-Arg-ß-naphthylamide dihydrochloride and 1-(1-naphthylmethyl)-piperazine indicated the involvement of efflux pumps in the FQ resistance of only a few CCF isolates. Finally, genetic profiling showed that there was no evidence of A. baumannii outbreaks in CCFs. Instead, our analyses revealed only limited clonal dissemination of mostly non-MDR A. baumannii strains in a few facilities. This study represents the first report to characterize phenotypic and molecular features of Acinetobacter isolates in correctional facilities, which provides a baseline for monitoring the antimicrobial resistance changes and dissemination patterns of these organisms in such specialized institutions.
Subject(s)
Acinetobacter Infections/microbiology , Acinetobacter/classification , Acinetobacter/isolation & purification , Acinetobacter/genetics , Acinetobacter/physiology , Adult , Aged , Anti-Bacterial Agents/pharmacology , Bacterial Typing Techniques , California , Cluster Analysis , Drug Resistance, Bacterial , Female , Genotype , Humans , Integrons , Male , Microbial Sensitivity Tests , Middle Aged , Molecular Epidemiology , Molecular Typing , Prisons , Young AdultABSTRACT
The reflection resonance spectrum of a subwavelength diffraction-grating-coupled waveguide is used to analyze biomolecular interactions in real time. By detecting this resonance wavelength shift, the optical waveguide biosensor provides the ability to identify the kinetics of the biomolecular interaction on an on-line basis without the need for extrinsic labeling of the biomolecules. A theoretical analysis of the subwavelength optical waveguide biosensor is performed. A biosensor with a narrow reflection resonance spectrum, and hence an enhanced detection resolution, is then designed and fabricated. Currently, the detection limit of the optical waveguide sensor is approximately 10(-5) refractive-index units. The biosensor is successfully applied to study of the dynamic response of an antibody interaction with protein G adsorbed on the sensing surface.
Subject(s)
Biosensing Techniques/instrumentation , Immunoassay/instrumentation , Nerve Tissue Proteins/analysis , Optics and Photonics/instrumentation , Protein Interaction Mapping/instrumentation , Refractometry/instrumentation , Biosensing Techniques/methods , Immunoassay/methods , Nerve Tissue Proteins/immunology , Protein Interaction Mapping/methods , Refractometry/methodsABSTRACT
OBJECTIVE: To analyze the clinical diagnosis and treatment of hepatic hydatid disease and its epidemiological characteristics in Yili river valley. METHODS: Retrospective investigation was carried out on 2049 cases collected in 1993-2003. Clinical diagnosis was made by ways of intradermal test, serological test, ultrasound, X-ray, CT and/or MRI, majority of them received surgical operation. RESULTS: Among the 2049 cases, cystic hydatidosis occupied 96% (1965/2049), while 4% (84/2049) were alveolar hydatidosis. 99% (2034/2049) accepted surgery including hepatolobectomy, endocystomy and hydatidostomy in 302 cases (14.7%) without relapses. 754 cases (36.7%) received chemotherapy (praziquantel, albendazole) after surgical operation. The disease distributed in agri-pastoral areas along the valley. Local residents from different minorities had a close contact with dogs, 54% of the cases were females and 48% of the cases were in the group of 25-49 years old. The incidence tends to decline in the years. CONCLUSION: Hydatidosis is still an important health problem in the region. Further practices for improving treatment especially surgical intervention and for epidemiological investigation are needed.