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PubMed1998

Amerindian pyruvate carboxylase deficiency is associated with two distinct missense mutations.

We characterized the pyruvate carboxylase (PC) gene by PCR amplification, subcloning, and sequencing. The coding region has 19 exons and 18 introns spanning approximately 16 kb of genomic DNA. Screening both the cDNA and the gene of individuals with the simple A form of PC deficiency revealed an 1828G-->A missense mutation in 11 Ojibwa and 2 Cree patients and a 2229G-->T transversion mutation in 2 brothers of Micmac origin. Carrier frequency may be as high as 1/10 in some groupings. The two point mutations are located in a region of homology conserved among yeast, rat, and human PC, in the vicinity of the carboxylation domain of the enzyme. These data provide the first characterization of the human PC gene structure, the identification of common pathogenic mutations, and the demonstration of a founder effect in the Ojibwa and Cree patients.

Amino Acid Sequence↗
PubMed2006

Staphylococcus aureus small colony variants in prosthetic joint infection.

BACKGROUND: Small colony variants of Staphylococcus aureus tend to persist despite antimicrobial therapy, especially when involved in implant-associated infections. METHODS: We analyzed 5 cases of hip prosthesis-associated infections due to small colony variants, including their course prior to identification of the pathogen. Biopsy investigations included microbiological examination and, in 1 case, transmission electron microscopy to detect intracellular bacteria in nonprofessional phagocytes. A treatment concept was elaborated on the basis of a published algorithm and patients were managed accordingly. RESULTS: The patients' mean age was 62.2 years. All patients experienced treatment failures prior to isolation of small colony variants, despite as many as 3 surgical revisions and up to 22 months of antibiotics. Transmission electron microscopy performed on biopsy specimens from periprosthetic tissue revealed intracellular cocci in fibroblasts. All prostheses were removed without implanting a spacer, and antimicrobial agents were administered for 5.5-7 weeks. Reimplantation of the prosthesis was performed for 4 patients. Follow-ups were uneventful in all 5 cases. CONCLUSIONS: In the case of a poor response to adequate antimicrobial and surgical treatment in implant-associated staphylococcal infections, small colony variants should be considered and actively sought. In our case series, a 2-stage exchange without implantation of a spacer combined with antimicrobial therapy for an implant-free interval of 6-8 weeks was associated with successful outcome, with a mean follow-up of 24 months.

Aged↗
PubMed1978

The role of the microbiology laboratory in surveillance and control of nosocomial infections.

The microbiology laboratory's rapid and consistent identification of nosocomial pathogens is a keystone in the surveillance and control of hospital-acquired infections. In addition, the laboratory serves as a source of expert consultation for clinicians and infection control personnel and as an "early warning center" for infection problems. In making its contributions to infection control most effective, the laboratory must recognize its capabilities and limitations, must insure that the materials and methods it uses and the specimens it processes meet high standards, must provide retrievable records, and must have a good working knowledge of microbiologic technics used to evaluate both endemic and epidemic infections. Moreover, because laboratory workers come into contact daily with potentially infectious specimens and isolates, the laboratory's contributions to infection control should also include the prevention and surveillance of laboratory-acquired infections.

Cross Infection↗
PubMed1992

Evaluation of new anti-infective drugs for the treatment of acute bacterial meningitis. Infectious Diseases Society of America and the Food and Drug Administration.

Predisposing conditions for acute bacterial meningitis include prematurity, young age, management in an intensive care setting, low socioeconomic background, and crowded living conditions. Clinical findings vary with age and may be nonspecific (altered feeding behavior) or specific (Kernig and Brudzinski signs). Examination and culture of cerebrospinal fluid (CSF) are essential for diagnosis. Antigen identification in CSF, serum, or urine by latex agglutination or other techniques can be useful in the identification of the pathogen. Randomized, controlled studies with a single-, double-, or evaluator-blinded design are encouraged. Among neonates, infants, and children, CSF should be examined again 24-36 hours after initiation of therapy. Outcomes should be judged by both clinical and microbiological criteria. Assessment of microbiological outcome is paramount.

Acute Disease↗
PubMed1993

Persistent bacteremia with Erysipelothrix rhusiopathiae in a hospitalized patient.

A patient with a history of alcohol abuse and pancreatitis presented with a pleural effusion resulting from a fistula between the pancreatic duct and left pleural space. Two weeks into her hospitalization, fever and persistent bloodstream infection with Erysipelothrix rhusiopathiae and Candida albicans developed. The patient had no history of exposure to animals. To our knowledge this is the first report of an E. rhusiopathiae infection presenting during hospitalization. This case suggests the possibility of a carrier state of infection and illustrates that a high index of suspicion is necessary for identification of unusual pathogens in hospitalized patients.

Adult↗
PubMed1983

Differentiation of neisseriaceae by isoenzyme electrophoresis.

Analysis of 71 strains of Neisseriaceae by starch-gel electrophoresis of hexokinase, phosphoglucomutase, glucose phosphate isomerase, and L-malate-nicotinamide adenine dinucleotide phosphate oxidoreductase showed that all gonococci and all memingococci have a characteristic hexokinase isoenzyme that is specific for each species and clearly distinguishes meningococci and gonococci from each other and from other species of Neisseriaceae. Strains of gonococci that were transformed into maltose utilizers by DNA from Neisseria lactamica and Neisseria meningitidis showed no change in the isoenzymes so that they could still be differentiated from meningococci and other Neisseriaceae by isoenzyme electrophoresis. In view of the limited sensitivity and specificity of conventional tests for the identification of gonococci and the possibility that gonococci may be transformed into maltose utilizers by DNA from normal throat flora, electrophoresis of hexokinase isoenzymes should be useful for the precise laboratory identification of the pathogenic neisseriae, especially those from atypical sites and those giving indeterminate reactions.

Electrophoresis, Starch Gel↗
PubMed1994

Polymerase chain reaction detection of viruliferous Bemisia tabaci (Homoptera: Aleyrodidae) with two tomato-infecting geminiviruses.

The sweetpotato whitefly, Bemisia tabaci (Gennadius), is an important pest worldwide. A new biotype of sweetpotato whitefly, biotype B, causes damage by direct feeding and by the transmission of plant viruses, such as geminiviruses. In the Mediterranean area, tomato yellow leaf curl geminivirus (TYLCV) is the most serious disease of tomatoes. Another whitefly-transmitted geminivirus, tomato mottle geminivirus (ToMoV), is presently a serious problem in tomato production in west-central and southwestern Florida. Because of the increasing incidence of whitefly-transmitted geminiviruses, it is necessary to develop rapid and simple diagnostic methods for the detection of viruliferous whiteflies. The polymerase chain reaction is a sensitive and specific technique for the detection and identification of plant pathogens. Polymerase chain reaction methods were used successfully to amplify 1.1-kb DNA fragments from individual viruliferous B. tabaci carrying either TYLCV or ToMoV, and no amplified DNA fragments were obtained when nonviruliferous B. tabaci adults were processed similarly. Southern hybridization analysis proved that fragments amplified from viruliferous B. tabaci adults were viral DNA. This polymerase chain reaction-based detection method is sensitive enough to detect TYLCV and ToMoV in individual viruliferous B. tabaci in mixed samples of up to 25 (1 viruliferous: 24 nonviruliferous) and 10 (1 viruliferous: 9 nonviruliferous) individuals, respectively. The potential uses of this polymerase chain reaction-based detection method in epidermiological studies of geminiviruses are discussed.

Animals↗
PubMed2002

Effect of enriched thioglycolate on direct examination of respiratory specimens and guiding initial empirical therapy in intubated patients with pneumonia: a prospective, randomized study.

OBJECTIVE: To evaluate the use of enriched thioglycolate as a transport medium of protected specimen brush samples, in particular its value in direct examination of respiratory specimens and in guiding initial antibiotic prescription. DESIGN: Prospective, randomized, pilot study. SETTING: Medical-surgical teaching intensive care unit. SUBJECTS: Thirty adults with suspected ventilator-associated pneumonia. INTERVENTION: Bronchoscopy was performed by using standard techniques, and two consecutive protected specimen brush samples were taken. Transport medium consisted of 1 mL of sterile saline or thioglycolate. Gram stains were performed in all samples. Randomization was used to select which transport medium was used first. Each patient served as his or her own control. The laboratory was blind to the choice. MEASUREMENTS AND MAIN RESULTS: Causative agents were cultured in 16 episodes, and no significant differences were observed when the transport media were compared. Anaerobes were identified in only one episode. Direct staining in thioglycolate samples anticipated the presumptive diagnosis (in presence of false-negative cultures) in three additional patients in whom prior antibiotic therapy was prescribed; this was also the case in one patient with saline solution. The etiology was anticipated by direct Gram staining and permitted a more targeted initial empirical treatment in 75% of samples transported in thioglycolate, compared with only 37.5% of samples transported in saline solution (p <.05). CONCLUSION: When protected specimen brush samples are obtained, thioglycolate may contribute to early identification of the pathogen and may guide the initial empirical therapy.

Adult↗
PubMedDate not supplied

Cefotaxime therapy of neonatal gram-negative bacillary meningitis.

Seven neonates were treated with cefotaxime during eight episodes of Gram-negative bacillary meningitis and sepsis. The causative organisms were Escherichia coli in six cases and Klebsiella pneumoniae and Enterobacter sakazakii in one each. After identification of the pathogen cefotaxime was used alone in six instances. Two patients with brain abscesses received adjunctive therapy with another antibiotic. The sterility of cerebrospinal fluid was documented after a mean of 3.3 days of therapy. Mean cerebrospinal fluid bactericidal titer was 1:64. All patients recovered with good neurologic outcome. Cefotaxime in a dosage of 150 mg/kg/day divided every 6 hours intravenously seems safe and effective therapy for neonatal Gram-negative bacillary meningitis.

Cefotaxime↗
PubMedDate not supplied

The clinical diagnosis of genital ulcer disease in men in the tropics.

Since the clinical diagnosis of genital ulcers without laboratory confirmation is not reliable in developed countries, we postulated that clinical diagnosis alone would be no more reliable in developing countries. A presumptive clinical diagnosis of chancroid, genital herpes, syphilis, or lymphogranuloma venereum was made for 100 male patients at the Special Treatment Clinic in Nairobi, Kenya. This diagnosis was then compared to the final diagnosis determined by laboratory identification of the pathogen, by culture, or by serologic response. In 64 patients, a final diagnosis of either chancroid, syphilis, or genital herpes was established. The diagnostic accuracy varied from 75% for chancroid to 42% for syphilis and 43% for herpes. The overall diagnostic accuracy was 66%. The predictive values of positive clinical diagnoses were 84% for chancroid, 60% for syphilis, and 75% for herpes. Thus, clinical diagnosis of genital ulcer disease was not sufficiently reliable in this study.

Chancre↗
PubMed1989

Tularemic pneumonia mimicking Legionnaires' disease with false-positive direct fluorescent antibody stains for Legionella.

Pleuropulmonary tularemia may mimic atypical pneumonia caused by other common etiologic agents, including Legionella. The correct identification of the pathogen responsible for the atypical pneumonia is usually made serologically or with the use of special stains and cultures. We have reported a case of pleuropulmonary tularemia whose diagnosis was confounded by false-positive direct fluorescent antibody stains for Legionella.

Adult↗
PubMed1997

Corneal and conjunctival infections.

Recent advances in the field of infectious conjunctivitis and keratitis include new diagnostic methods, the identification of new pathogens, and novel therapeutic agents. Tandem confocal microscopy has been used to diagnose Acanthamoeba keratitis, and polymerase chain reaction has proven to be a rapid and sensitive technique for detecting specific viral antigens, particularly in cases where cultures yield no growth. Two new antiviral agents, ganciclovir and carbocyclic oxetanocin G, have been shown to be as effective as acyclovir in treating herpetic epithelial disease. The fluoroquinolones, especially ofloxacin, have become the antimicrobial agents of choice in the initial management of selected cases of bacterial keratitis.

Anti-Infective Agents↗
PubMed2006

The diagnostic value of serum interleukins 6 and 8 in children with acute gastroenteritis.

OBJECTIVES: Early identification of the pathogen causing acute gastroenteritis in children helps the physicians managing the disease and prevents unnecessary antibiotic treatment. C-reactive protein (CRP), interleukin (IL) 6 and IL-8 play a major role in immune responses and have been studied in a large number of infectious and noninfectious inflammatory diseases. The purpose of this study was to determine the serum IL-6 and IL-8 concentrations early in the course of acute gastroenteritis to see if these cytokines were useful diagnostic markers in differentiating viral from bacterial gastroenteritis. METHODS: Interleukin 6, IL-8 and CRP were measured in 18 patients with bacterial gastroenteritis, 21 patients with viral gastroenteritis and 17 healthy children. RESULTS: Interleukin 6 and CRP concentrations in patients with bacterial gastroenteritis were significantly higher than those in patients with viral gastroenteritis and healthy controls (P < 0.001). IL-8 concentrations in patients with viral and bacterial gastroenteritis were both increased and were not statistically different. IL-6 and IL-8 levels had diagnostic sensitivities of 79% and 50% and specificities of 86% and 67%, respectively. The combination of IL-6 and CRP had a sensitivity of 94%, specificity of 71%, a positive predictive value of 74% and a negative predictive value of 93.75%. CONCLUSIONS: Serum IL-6 may be a useful marker for early differentiation of viral and bacterial gastroenteritis in children, especially in combination with CRP.

Acute Disease↗
PubMed2007

Serum cytokine differences in severely burned children with and without sepsis.

The aim was to determine whether serum cytokine profiling early after burn can be used to identify patients at high risk of developing and subsequently dying of sepsis. A case series study was designed to determine whether serum cytokine profiling allows identification of patients at highest risk of developing and dying of sepsis at the time of hospital admission. All patients were treated according to the standard of burn care at our facility. Forty-four children (1-19 years old) with more than 40% of total body surface area and admitted within 7 days postburn were studied. None had infections or sepsis at the time of admission. Serum was collected before the first operation, and concentrations of 17 cytokines were measured. Diagnosis of sepsis was made at autopsy with identification of the pathogen. Fifteen patients developed sepsis and died, whereas 29 patients did not develop sepsis and survived. Significant elevations in serum interleukin (IL) 6, IL-8, IL-10, granulocyte-monocyte colony-stimulating factor, interferon gamma (IFN-gamma), tumor necrosis factor (TNF), and IL-12 p70 were found at the time of admission of patients who subsequently developed and died of sepsis when compared with burned patients who did not develop sepsis (P < 0.05). Multiple logistic regression analysis revealed that patients with a combination of elevated IL-6 and IL-12 p70 and lower TNF had an elevated risk of dying of sepsis. Serum IL-6, IL-8, IL-10, granulocyte-monocyte colony-stimulating factor, IFN-gamma, TNF, and IL-12 p70 are expressed differently in patients who die of sepsis versus those who never become septic. In addition, serum IL-6, IL-12 p70, and TNF can be used to identify burned patients who are at high risk of death from sepsis.

Burns↗
PubMed2006

Evaluation of a new chromogenic agar for the detection of Listeria in food.

AIM: Rapid identification of Listeria in food is important in protecting consumers from infection. The development of chromogenic media such as agar Listeria according to Ottaviani and Agosti (ALOA) has allowed more rapid detection of Listeria monocytogenes, with presumptive identification of this pathogenic species after only 24 h of incubation. The aim of this study was to evaluate Oxoid chromogenic Listeria agar (OCLA) in comparison with ALOA and a traditional, nonchromogenic medium, Oxford agar. METHODS AND RESULTS: Media were compared using pure cultures, spiked food samples and naturally contaminated samples. Whilst development of typical colony morphology took 48 h on Oxford agar, Listeria spp. were frequently detected after 24 h of incubation on OCLA and ALOA. There was no significant difference in recovery between the two chromogenic media. CONCLUSIONS: Results indicate that OCLA gives equivalent recovery of Listeria spp. compared with ALOA. Whilst L. monocytogenes was frequently detected after 24 h of incubation, a 48-h incubation time was necessary to ensure detection of both L. monocytogenes and other Listeria spp. SIGNIFICANCE AND IMPACT OF THE STUDY: This study has shown that a commercially available chromogenic medium other than ALOA is appropriate for use in the international standard method. The commercial availability of more than one medium will facilitate the more widespread use of the method, thus increasing confidence in the ability to detect L. monocytogenes in food in the presence of other Listeria spp.

Agar↗
PubMed1982

The evaluation of autofluorescence emission spectra derived from neuronal lipopigment.

A method for measuring the emission spectra from regions of neuronal lipopigment in tissue sections is described and illustrated. Each emission spectrum was derived from the means of six sets of readings, from either six regions of lipopigment from six neurones which were presumed to be from a homogeneous cell population, or from one region of one neurone. Characteristics of the emission spectra from lipopigment in various forms of neuronal ceroid-lipofusinoses (NCLs) and in brains without evidence of NCL are presented and discussed. The results indicate that the classification of lipopigments should not be restricted to the two categories of 'lipofuscin' and 'ceroid'. This method may aid the identification of various pathogenic mechanisms in neurones, and provide another means of investigating the effects of certain drugs on cerebral function.

Aged↗
PubMedDate not supplied

Successful treatment of cerebral aspergillosis by stereotactic operation and antifungal therapy.

The following is a case report of a cerebral Aspergillus abscess in a male patient predisposed to this disease on account of many years of alcohol abuse. After timely identification of the pathogenic organism, the patient was cured by stereotactic operation in conjunction with antifungal therapy using amphotericin B and 5-fluorocytosine. The origin and the starting point of the infection remain obscure.

Amphotericin B↗
PubMed1996

Diagnosis and treatment of bacterial pneumonia in Korea.

Even with advancements in knowledge the problem of pneumonia will not be eliminated. It should be understood who is at risk, why such people develop pneumonia, what causes the pneumonia, and respiratory infection should be managed and prevented. The relative frequency of the isolation of various etiologic agents that cause bacterial pneumonia differ according to age group, geography, socio-economic status, underlying disease, time of year, and possible concomitant viral illnesses. Prompt identification of the causative agent is vital in the management of pneumonia. The present status of elucidating the etiologic agent is far from complete and recently, newer techniques using DNA probes and polymerase chain reactions were used for the identification of microbial pathogens. The timely use of appropriate systemic antibacterial therapy eradicates the pathogens. Considering the alterations of the etiologic agents of bacterial pneumonia and antibiotic susceptibilities, attention should be directed to the usage of antimicrobial agents in order to maximize the efficacy and the therapeutic implications.

Community-Acquired Infections↗