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Methods of quantifying and visualising outbreaks of tuberculosis using genotypic information.

Genotypic data from pathogenic isolates are often used to measure the extent of infectious disease transmission. These methods include phylogenetic reconstruction and the evaluation of clustering indices. The first aim of this paper is to critique current methods used to analyse genotypic data from molecular epidemiological studies of tuberculosis. In particular, by not accounting for the mutation rate of markers, errors arise in making inferences about outbreaks based on genotypic information. The second aim is to suggest a new way to represent genotypic data visually, involving graphs and trees. We also discuss some interpretations and modifications of existing indices. Although our focus is tuberculosis, the methods we discuss are generally applicable to any directly transmissible clonal pathogen.

Cluster Analysis↗

Complete nucleotide sequence of the geminivirus tomato yellow leaf curl virus, Thailand isolate.

The complete genome of a Thailand isolate of the geminivirus tomato yellow leaf curl virus (TYLCV-Th) has been cloned and the nucleotide sequence determined. The genome consists of two DNAs each slightly greater than 2700 nucleotides in length and designated A-DNA and B-DNA. The A-DNA contains six open reading frames (ORFs) capable of encoding proteins with M(r)s greater than 10K; two ORFs were located on the B-DNA. The predicted ORFs were found at positions on the genome similar to those identified in other geminiviruses. Based upon computer-assisted sequence comparisons with other geminiviruses, TYLCV-Th maintained the greatest degree of similarity with a tomato pathogen isolated in Australia, tomato leaf curl virus. Furthermore, sequence comparisons with a large number of geminiviruses confirm further divisions of the geminiviruses based upon geographical proximity of the viruses. Agroinoculation of Nicotiana benthamiana with a TYLCV-Th A-DNA clone containing a mutation in the capsid protein ORF demonstrated that the coat protein is not essential for TYLCV-Th infection but enhances the progression of the disease.

Base Sequence↗

Predictors of physician confidence to diagnose pneumonia and determine illness severity in ventilated patients. Australian and New Zealand practice in intensive care (ANZPIC II).

The manner in which elements of clinical history, physical examination and investigations influence subjectively assessed illness severity and outcome prediction is poorly understood. This study investigates the relationship between clinician and objectively assessed illness severity and the factors influencing clinician's diagnostic confidence and illness severity rating for ventilated patients with suspected pneumonia in the intensive care unit (ICU). A prospective study of fourteen ICUs included all ventilated admissions with a clinical diagnosis of pneumonia. Data collection included pneumonia type - community-acquired (CAP), hospital-acquired (HAP) and ventilator-associated (VAP), clinician determined illness severity (CDIS), diagnostic methods, clinical diagnostic confidence (CDC), microbiological isolates and antibiotic use. For 476 episodes of pneumonia (48% CAP, 24% HAP, 28% VAP), CDC was greatest for CAP (64% CAP, 50% HAP and 49% VAP, P<0.01) or when pneumonia was considered "life-threatening" (84% high CDC, 13% medium CDC and 3% low CDC, P<0. 001). "Life-threatening" pneumonia was predicted by worsening gas exchange (OR 4.8, CI 95% 2.3-10.2, P<0.001), clinical signs of consolidation (OR 2.0, CI 95% 1.2-3.2, P<0.01) and the Sepsis-Related Organ Failure Assessment (SOFA) Score (OR 1.1, CI 95% 1.1-1.2, P<0.001). Diagnostic confidence increased with CDIS (OR 16.3, CI 95% 8.4-31.4, P<0.001), definite pathogen isolation (OR 3.3, CI 95% 2.0-5.6) and clinical signs of consolidation (OR 2.1, CI 95% 1.3-3.3, P=0.001). Although the CDIS, SOFA Score and the Simplified Acute Physiologic Score (SAPS II) were all associated with mortality, the SAPS II Score was the best predictor of mortality (P = 0. 02). Diagnostic confidence for pneumonia is moderate but increases with more classical presentations. A small set of clinical parameters influence subjective assessment. Objective assessment using SAPS II Scoring is a better predictor of mortality.

Adolescent↗

Genetic relatedness amongst intestinal spirochaetes isolated from rats and birds.

Multilocus enzyme electrophoresis was used to determine genetic relationships amongst 32 intestinal spirochaetes (Serpulina spp.) isolated from rats (17), rheas (7), chickens, (4), ducks (2), a swan (1) and a flamingo (1). The strains were divided into 20 electrophoretic types (ETs), with a mean genetic diversity per locus of 0.62. The results were compared with those previously published for porcine intestinal spirochaetes. One strain from a healthy rat, and three rhea strains which were recovered from cases of necrotizing typhlitis, were grouped in the same ETs as certain porcine strains of Serpulina hyodysenteriae. The rhea strains could be differentiated from these by pulsed-field gel electrophoresis. Fifteen of the rat strains were genetically and phenotypically closely related. In contrast the avian strains were genetically more heterogeneous, with pathogenic isolates located in three different genetic groups.

Alleles↗

Population-based prevalence of symptomatic and asymptomatic astrovirus infection in rural Mayan infants.

Symptomatic and asymptomatic astrovirus infection was prospectively determined in a 3-year birth cohort of Mayan infants. Stool samples from 271 infants and 268 older siblings were tested for astrovirus, adenovirus 40/41, rotavirus and Salmonella, Shigella and Campylobacter species. Concurrent diarrhea, vomiting, fever, or anorexia were noted. Astrovirus was detected in 164 infants (61%) and 20 siblings (7%). Rotavirus (4%) and adenovirus 40/41 (13%) were isolated less frequently. Of all diarrheal episodes reported at a visit, 26% (78/305) were associated with astrovirus; 17% (78/452) of astrovirus infections were associated with diarrhea and 9% with other symptoms. Only diarrhea was associated with astrovirus infection (odds ratio, 1.4; 95% confidence interval [CI], 1.07-1.92; P = .01). Of infants with astrovirus, 70% shed at multiple visits over a period of 2-17 weeks (median, 5). The point prevalence of astrovirus infection was significantly higher among infants than siblings (relative risk, 6.18; 95% CI, 3.93-9.72; P < .0001, chi2). Astrovirus was identified throughout the year, peaked in March and May, and decreased in September. In this population, astrovirus was the most common enteric pathogen isolated; symptomatic infection was prevalent among infants.

Adenoviridae Infections↗

Sensitivity and specificity of daily tracheal aspirate cultures in predicting organisms causing bacteremia in ventilated neonates.

The sensitivity of daily tracheal aspirates in predicting neonatal bacteremia was ascertained from 48 of 354 ventilated neonates who became septic during a 4-year period. Fourteen babies (designated Group A) had a positive blood culture on the first day of life; 28 infants (Group B) and 6 infants (Group C) had bacteremia beyond the first day. Group C infants became septic as a result of intraabdominal pathology. Pathogens isolated from blood were correlated with those from preceding daily tracheal aspirates. The overall sensitivity of tracheal cultures in predicting results of blood cultures was 81% (Group A, 71%; Group B, 93%; Group C, 50%). The specificity of daily tracheal aspirates was ascertained from 28 of 50 ventilated infants who were nonseptic and had negative blood cultures during a 6-month period. Only 18 had consistently sterile tracheal aspirates (specificity, 64%). The mean number of days of intubation was 6.6 for the 10 false positive and 3.6 for the 18 true negative. Because of low positive predictive value (0.26) the role of daily tracheal aspirate culture is limited to providing early information regarding potential pathogens when sepsis occurs rather than to identify babies who are going to become septic.

Escherichia coli↗

Etiology and cytokine expression in patients requiring mechanical ventilation due to severe community-acquired pneumonia.

BACKGROUND: The relationship between bacterial etiology and serum cytokine levels in patients with severe community-acquired pneumonia (CAP) without response to initial empiric treatment remains unclear. This study investigated the bacterial etiology, outcomes, and bronchoalveolar and systemic cytokines (interleukin [IL]-1beta, IL-8, IL-10) in these patients. METHODS: This hospital-based study enrolled 47 consecutive patients without response to initial empiric treatment and requiring mechanical ventilation due to severe CAP between July 1, 2000 and October 31, 2001, in a respiratory intensive care unit of a 1200-bed teaching hospital in central Taiwan. Bronchoalveolar lavage (BAL) was performed within 3 days after hospitalization. BAL fluid was processed for quantitative bacterial cultures. Blood samples were taken just before BAL, and the levels of both BAL and serum cytokines were measured. RESULTS: The most common pathogens isolated were Pseudomonas aeruginosa (22.5%) and Klebsiella pneumoniae (25%). Patients with a K. pneumoniae isolate (n = 10) had significantly higher levels of IL-1beta in BAL fluid and significantly higher levels of IL-10 in serum and BAL fluid than patients with other etiologies. Non-survivors had higher levels of serum IL-8 (p = 0.001), serum IL-10 (p < 0.001) and BAL IL-10 (p = 0.039) than survivors. Marked increases in local and systemic cytokine expression (IL-8 and IL-10) were noted in rapidly fatal cases. CONCLUSION: P. aeruginosa and K. pneumoniae are the most common causes of CAP requiring mechanical ventilation in Taiwan. Cytokine patterns in the BAL fluid and serum of patients with severe CAP due to K. pneumoniae showed significant elevations compared to other pathogens. Bronchoalveolar and systemic cytokine levels (especially IL-10) predicted mortality. These findings suggest the need for a clinical trial to determine how immunomodulating therapy might affect cytokine profiles and clinical outcome.

Aged↗

Molecular typing study of the Microsporum canis strains isolated from an outbreak of tinea capitis in a school.

Tinea capitis is a dermatophyte infection of the scalp that occurs most often in prepubescent children. Tinea capitis may be transmitted by shared use of contaminated hairbrush, by contact with fomites or by direct physical contact with an infected person. Occasionally, outbreak of tinea capitis would happen under some special conditions. Last year, we found an outbreak of tinea capitis in a school due to Microsporum canis. In epidemiological study, we performed the prevalence survey to all of the exposed persons by physical examinations and mycological laboratory tests, including KOH preparation and fungal cultures. We also investigated the environment in the school. In molecular typing study of the M. canis isolated from patients and the environment, random primer amplification polymorphic DNA (RAPD) method, the specific amplification of subrepeat element in the ribosomal DNA nontranscribed spacer (NTS), and the analysis of DNA sequence in the intertranscribed spacer (ITS) of rDNA were performed. The total number of exposed children was seventy-one, among them forty-two were attacked by tinea capitis. The ratio between boy and girl was 13:1. The ages of the patients was ranged from 3.5 years old to 10 years old. Four patients bred cat or dog as pet. Most patients appeared noninflammatory type of tinea capitis and several patients were inflammatory type. Under microscopic examination the invaded hair were all ectothrix. The pathogens isolated from these patients were M. canis. And we also isolated M. canis from the carpet and the pillowcase in the school. The patterns of total strains of M. canis in the RAPD method and PCR amplification of the rDNA NTS region study were identical, and the isolates from patients and the environment contained the same DNA sequences in the ITS region. The outbreak of tinea capitis was caused by M. canis. The M. canis isolated from patients and from the environment were probably the same origin.

Child↗

LAV/HTLV-III infection in children of African origin: experience in Belgium.

From December 1982 to June 1985, we diagnosed LAV/HTLV-III infection in 16 children of African origin living in Belgium or referred to one of the hospitals participating in this study. Diagnosis was proven in seven of them by isolation of virus of the LAV/HTLV-III group. In the nine others, LAV/HTLV-III infection was highly probable because of the presence of antibodies against the virus (seven subjects) or clinical and immunological evidence of immune deficiency associated with a parental history of LAV/HTLV-III infection (two subjects). Five of these children had a severe illness starting in the first months of life (range 20 days--4 months) and died within 4 months (range 19 days--10 months). Eight children presented later in life (mean age 35 months, range 2-66 months) with a milder and more chronic disease characterized by the presence of generalized lymphadenopathy (6/8), hepatomegaly (5/8), splenomegaly (5/8), interstitial pulmonary infiltration (4/8), parotid swelling (3/8), CSF lymphocytosis (3/5), diarrhoea without pathogen isolated (1/8) and fever (1/8). At least one of the parents of each child was of African origin. At the time of birth of their child two mothers and one father had an AIDS-related complex. After a mean period of 34 months (range 3-87 months) five fathers and six mothers had a symptomatic LAV/HTLV-III infection (AIDS or AIDS-related complex).

Acquired Immunodeficiency Syndrome↗

Thrombus with infection in total artificial heart animals.

From January 1980 to December 1990, several types of total artificial hearts were implanted into 378 animals. In a retrospective study of these animals, 147 (39%) were found to have thrombus with infection (T&I). The criteria for diagnosis was thrombus formation in the artificial heart and a positive blood culture. The most common pathogen isolated from T&I animals was Pseudomonas species. Concurrent skin lesions and contamination from the pressure lines may be the primary sources of infection, but bacterial translocation from the intestine is another possible route. The main pathological findings at necropsies of artificial heart animals with T&I were associated with sepsis, congestive heart failure, infected thrombus, thromboembolism, and multiple organ infarctions. Most thrombi appeared to have originated from valve junctions and connectors. On the basis of these observations, a possible mechanism for pathogenesis of T&I has been proposed. The results suggest that design improvements and surface modifications to reduce thrombosis are important factors that should be carefully considered. Similarly, it is important to eliminate the route of entry of pathogenic microorganisms. These findings imply that bacterial interaction with thrombus, device related bacterial colonization, and host immunomodulation and gut barrier function following artificial heart implantation need further investigation.

Animals↗

Severe community acquired pneumonia: a one-year analysis in a tertiary referral intensive care unit.

AIMS: To define outcomes, characteristics, microbiology and salient prognostic factors of patients admitted to our intensive care unit (ICU) with severe community acquired pneumonia, over a one year period. METHODS: All adult patients with severe community acquired pneumonia admitted between July 1997 and July 1998 were studied. Data were extracted by retrospective chart review. Variables assessed included underlying conditions and baseline physical parameters. Evolutionary variables eg, septic shock and laboratory data including microbiology and arterial blood gas determinants were also assessed. Prognostic factors were determined by comparison of the above variables between survivors and non-survivors. The prognostic value of the British Thoracic Society discriminant 'rule one' was assessed. Results. 32 patients were assessed. ICU mortality was 31%. 84% of patients had co-morbidity. The average age was 58.5 (SD 17.4) years and the average APACHE 11 score was 20.37 (SD 9.12). A microbiological diagnosis was made in 40%. Mortality was not increased in those in whom a bacterial diagnosis was not made. Commonest pathogens isolated were Streptococcus pneumoniae (46%), gram negative organisms (29%) and Staphylococcus aureus (23%). Prognostic factors on and during ICU admission were the need for mechanical ventilation (p=0.0003), septic shock (p=0.02), inotrope requirement (p=0.003), low serum albumin (p=0.041), base deficit (p=0.04), INR (p=0.02) and inspired oxygen concentration (p=0.003). On initial admission to hospital the presence of bilateral pneumonia was the only variable correlated with outcome (p=0.01). The British Thoracic Society 'rule one' did not correlate with death either on admission to hospital or ICU. CONCLUSIONS: Severe community acquired pneumonia carries a high mortality despite ICU management. Bacterial diagnostic rate was low but made no difference to mortality. Streptococcus pneumoniae was the commonest causative pathogen. The development of septic shock, requirement for mechanical ventilation and bilateral disease are important adverse prognostic indicators.

APACHE↗

The effect of HAART on salivary microbiota in the Women's Interagency HIV Study (WIHS).

OBJECTIVE: Study the prevalence of potentially pathogenic microorganisms in saliva of HIV-positive women in the Women's Interagency HIV Study. STUDY DESIGN: 157 HIV-positive and 31 HIV-negative women were studied. At baseline and every 6 months over 4 years, information was collected on socioeconomic and educational status, oral and systemic health, including HIV markers and antiretroviral therapy, and frequency of professional oral care utilization. Bacterial and yeast pathogenic isolates from stimulated whole saliva were tentatively identified using standard methodologies. RESULTS: The prevalence of microorganisms in stimulated saliva of HIV-positive women was not significantly different from that of HIV-negative women. In HIV-positive women, highly active antiretroviral therapy (HAART) was independently and significantly associated with the presence of a variety of salivary bacterial species. HAART increased the risk for recovering Fusobacterium species (P < .001), enteric gram-negative rods (P < .05), Peptostreptococcus micros (P < .05), Campylobacter species (P < .0001), Eubacterium species (P < .001), and Tannerella forsythia (P < .01). In contrast, HAART led to decreased recovery rate of yeasts (Candida albicans and Candida dubliniensis) (P < .0001). CONCLUSION: The present findings suggest that the institution of HAART promotes an increasingly pathogenic salivary microbiota, at least temporarily. Similar findings have been reported for various nonoral microbial ecosystems.

Adolescent↗

The association of rhinoviruses with lower respiratory tract disease in hospitalized patients.

An analysis of 32 hospitalized infants and children from whom rhinoviruses were isolated in our diagnostic laboratories in 1982-83 suggests that these agents are associated with lower respiratory tract disease with focal findings in susceptible patients. In 23 cases, an acute lower respiratory disease was the cause for admission, while nine patients were cultured after new respiratory symptoms developed during hospitalization. Presenting signs and symptoms included cough (23), fever (19), rhinorrhea (19), respiratory distress (14), and decreased feeding (15). Seventeen of 25 chest x-rays showed new focal abnormalities. Twenty-five patients had a significant underlying disease including seven with malignancies, six with respiratory tract abnormalities, and four with congenital heart lesions. Six of the remaining seven patients were less than 2 1/2 months of age. In no cases were significant bacterial or fungal pathogens isolated; two did have concomitant viral isolates. Rhinoviruses in the appropriate clinical setting are associated with significant pulmonary disease.

Adolescent↗

Sparfloxacin versus ciprofloxacin for the treatment of community-acquired, complicated skin and skin-structure infections.

Fluoroquinolones have been shown to be effective in the treatment of complicated skin and skin-structure infections, in part because of their broad-spectrum antibacterial activity against causative pathogens that are resistant to older antimicrobial agents. We enrolled 603 adult patients (>58% male, >85% white) in a double-masked, double-dummy, randomized, multicenter trial to compare the efficacy and tolerability of sparfloxacin (400-mg loading dose followed by 200 mg once daily) with those of ciprofloxacin (750 mg twice daily) for 10 days in the treatment of community-acquired, complicated skin and skin-structure infections. The primary efficacy variable was clinical response, based on assessment of signs and symptoms, in the clinically assessable population. Patients in the sparfloxacin and ciprofloxacin groups were comparable with respect to demographic characteristics, underlying diseases, medical history, and laboratory test results. Wound infection was the most common diagnosis, and Staphylococcus aureus was the most frequently isolated pathogen. For the 475 clinically assessable patients, the clinical success rate (percentage of patients cured or improved) was 90.1% (210/233) with sparfloxacin and 87.2% (211/242) with ciprofloxacin. In this analysis (95% confidence interval [CI], -2.8 to 8.6) and the intent-to-treat analyses (95% CI, -4.2 to 6.2), results with sparfloxacin were statistically equivalent to those with ciprofloxacin (95% CI, -1 to 15.3). For bacteriologically assessable patients, eradication rates were 87.0% (141/162) with sparfloxacin and 79.9% (123/154) with ciprofloxacin (95% CI, -1 to 15.3). Eradication rates of S. aureus and coagulase-negative staphylococcal infections were 90.2% (101/112) with sparfloxacin and 77.9% (88/113) with ciprofloxacin. For patients with 2 or more pathogens at baseline (mixed infections), bacteriologic success was 87.6% for sparfloxacin and 77.9% for ciprofloxacin. Pseudomonas aeruginosa infections were eradicated or presumed eradicated in 71.4% (10/14) of sparfloxacin-treated patients and 87.5% (7/8) of ciprofloxacin-treated patients. Overall success rates in the bacteriologically assessable patients for sparfloxacin (84.6% [137/162]) and ciprofloxacin (78.6% [121/154]) were statistically equivalent (95% CI, -2.5 to 14.5). Tolerability was assessed in all patients who received study medication. The overall frequency of treatment-related adverse events was comparable in the 2 treatment groups (26.5% sparfloxacin, 23.3% ciprofloxacin). Drug-related adverse events involving the digestive system occurred in 7.1% of sparfloxacin-treated patients and 19.0% of ciprofloxacin-treated patients; photosensitivity reactions were reported in 11.1% of patients in the sparfloxacin group and 0.7% of patients in the ciprofloxacin group (P < 0.001). The mean change in QTc interval from baseline to the maximum on-treatment value was greater in the sparfloxacin group (9 milliseconds) than in the ciprofloxacin group (3 milliseconds) (P = 0.005; 95% CI, 0.002 to 0.010). The efficacy of sparfloxacin was comparable to that of ciprofloxacin in the treatment of community-acquired, complicated skin and skin-structure infections, including those caused by staphylococci, the most common pathogens. Sparfloxacin's once-daily regimen, high skin-tissue penetration, and improved activity against gram-positive cocci make it a therapeutic alternative to ciprofloxacin for patients who are not at risk for photosensitivity reactions or adverse events associated with prolongation of the QTc interval.

Adult↗

[Bacteriologic surveillance of nosocomial septicemia and bacteremia in a pediatric hospital].

BACKGROUND: Nosocomial bloodstream infections in pediatrics are an important cause of morbidity and mortality. To identify pathogens causing nosocomial bloodstream infections, evaluate associated risk factors and take preventive measures, we conducted a prospective study from January 1995 to December 1995 at Saint-Vincent-de-Paul Hospital (Paris). PATIENTS AND RESULTS: All patients hospitalized more than 48 hours were included in the study. During this period, we recorded 21 bloodstream infections in 20 children. The incidence rate of nosocomial bloodstream infection was 1/1,000 admissions. Sixteen children were hospitalized in surgery, three in medical intensive care unit; the median day onset of infection was approximately 20 days. Recorded risk factors were: surgery, invasive procedures, central catheterization, bladder catheters, parenteral nutrition, device, endotracheal tube, antibiotic therapy before infection. The number of risk factors ranged from zero to six per patient. The most common isolated pathogens were in ten cases Gram positive cocci: five methicillin-sensible Staphylococcus aureus, four methicillin-resistant coagulase-negative staphylococci and one Streptococcus milleri. Other bacteria were seven enterobacteria, three Pseudomonas sp and three Candida sp. In 11 cases, the same bacteria as in bloodstream infection could be found: in three urine samples, in two tracheal samples, in two gastro-intestinal samples, two puncture sites, one device, and one umbilical catheter. CONCLUSION: In our study, 6.2% of positive blood culture were due to a nosocomial infection. We confirm the importance of Gram positive cocci, and particularly of methicillin-resistant coagulase negative staphylococci.

Adolescent↗

Current problems in antimicrobial therapy for bacterial enteric infection.

Trimethoprim/sulfamethoxazole is currently considered the treatment of choice for shigellosis and severe travelers' diarrhea. The problem with this combination regimen is inactivity against Campylobacter jejuni strains and other bacterial enteropathogens showing in vitro resistance to the drug. Resistance to trimethoprim/sulfamethoxazole among enteric pathogens has occurred frequently in certain areas of the world. A study of the in vitro susceptibility of enteric bacterial pathogens isolated from multiple countries was recently performed. The minimal inhibitory concentration of ciprofloxacin required to inhibit 90 percent of the 210 bacterial enteropathogens ranged from 0.25 micrograms/ml for C. jejuni to 0.016 micrograms/ml for enterotoxigenic Escherichia coli, Salmonella, and Shigella. In a clinical trial carried out in a United States student population that acquired diarrhea while in Mexico, it was shown that ciprofloxacin was as effective as trimethoprim/sulfamethoxazole and both were significantly (p less than 0.001) more effective than placebo. The average duration of diarrhea was 29 or 20 hours after initiation of treatment with ciprofloxacin or trimethoprim/sulfamethoxazole, respectively, compared with 81 hours in the placebo group. The antimicrobial agents were more efficacious than placebo in treating diarrhea caused by enterotoxigenic E. coli, invasive enteropathogens, and unknown pathogens. Ciprofloxacin and the quinolone derivatives are uniquely suited to the therapy of acute bacterial diarrhea in areas where C. jejuni is commonly found and where trimethoprim/sulfamethoxazole-resistant strains regularly occur.

Anti-Bacterial Agents↗

Expression of the linear DNA plasmid pRS64 in the plant pathogenic fungus Rhizoctonia solani.

The plant pathogenic isolate RI-64 of anastomosis group 4 of Rhizoctonia solani possesses three linear DNA plasmids (pRS64-1, -2, and -3). Unique poly(A)- RNA, 0.5 kb in length and hybridizable with the pRS64 DNAs was found in mycelial cells of the isolate RI-64. The overall homology at the nucleotide level between pRS64-1, -2, and -3, and the cDNA prepared from the poly(A)- RNA was 100%, 73%, and 84%, respectively. The open reading frames found in pRS64-1, -2, and -3 (ORF1-1, ORF2-1, and ORF3-1) are 68 amino acids long. The amino acids sequence showed no significant homology with known proteins. Extracts from Escherichia coli cells expressing ORF1-1 contain a specific protein of 7 kDa. Antisera raised against the ORF1-1 product obtained from E. coli cells cross-reacted with the specific proteins found in the mycelia. The results indicate that the DNA plasmids found in R. solani contain a sequence that encodes a specific protein which may be involved in determination of plant pathogenicity.

Amino Acid Sequence↗

Coagulase-negative staphylococci and sternal infections after cardiac operation.

BACKGROUND: Coagulase negative staphylococci (CoNS) have been recognized as important pathogens in nosocomial infections, especially in connection with implanted foreign materials. In cardiac operation they are among the most common pathogens isolated from infected sternal wounds. The definition of the infection is very important. In this study we focus on deep postoperative chest infections. METHODS: By studying 33 infected patients retrospectively and comparing them to 33 matched uninfected controls, we studied the characteristics and costs of the infections. RESULTS: Typical for these infections is the late and insidious onset, and that the infections initially give only minor symptoms such as pain, redness, and serous secretion. We found the following risk factors for infection: number of preoperative days in a hospital, the total length of the operation, and if the patient had undergone an early reoperation due to causes other than infection. This kind of infection more than doubled the hospital costs for the patients affected. CONCLUSIONS: Coagulase negative staphylococci are the most important pathogens in deep postoperative infections in this material. They cause infections that are difficult to recognize since they give only discrete symptoms and start well after the patients leave the hospital. The risk factors for patients with CoNS infections are mostly associated with a long exposure to the hospital environment. The treatment is often difficult and costly because of multiresistant bacteria and frequent need for repeated surgical revisions.

Cardiac Surgical Procedures↗