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[Pathogen detection in blood culture. Contamination, colonization or infection].

Sepsis is a severe and life-threatening disease that requires a rapid and reliable diagnosis. The detection of microorganisms in blood culture and the results of in vitro anti-microbial susceptibility testing are prerequisites for a directed and cost-effective antimicrobial therapy. Microbiological results are difficult to interpret if contamination of the blood culture with colonizing or environmental germs cannot be ruled out. The source of contamination is predominantly inappropriate withdrawal of blood. Occasionally, contamination of blood cultures occurs in the laboratory. A potentially relevant blood culture result is already indicated by the isolated pathogen itself. In addition, a short time between the collection of blood and the isolation of the microorganism as well as the detection of the same pathogen in several blood cultures even more suggest a clinically relevant result.

Bacteriological Techniques↗

Microbial invasion of the amniotic cavity at birth is associated with adverse short-term outcome of preterm infants.

AIMS: To determine the frequency and clinical significance of microbial invasion of the amniotic cavity at the time of delivery in preterm infants. METHODS: Prospective cohort study during June 2001 and January 2002. Preterm infants < 33 + 6 weeks of gestation who had amniotic fluid and placental tissue sampled for culture during cesarean section were included. RESULTS: Of a total of 80 neonates, 42 had negative culture results, 22 had growth of Ureaplasma urealyticum, and 16 had growth of other pathogens. Isolation of Ureaplasma urealyticum was associated with a decreased risk of developing hyaline membrane disease after birth but a more than 20 times increased risk of developing chronic lung disease. Patients with growth of other pathogens had a significantly higher mortality than patients with negative culture results. CONCLUSIONS: Isolation of miroorganisms from the amniotic cavity at birth is associated with an adverse outcome of the preterm infant. In the light of extremely small numbers of positive blood cultures in preterm infants after birth, we consider it reasonable to recommend routine culturing of amniotic cavity tissues/fluid obtained during cesarean section in order to increase the identification rate of pathogens potentially involved in the pathogenesis of perinatal infections.

Chorioamnionitis↗

Screening for urinary tract infection with the Mastascan Elite.

Mastascan Elite urine screen (MUS) is compared to a conventional method to determine significant growth of urinary pathogens and determine identification and susceptibility. MUS can detect at least 10(3) colony-forming units (cfu)/mL of commonly isolated pathogens and in this study identified 161 true positive bacterial growths (15.2%), 840 true negatives (79.2%), 54 false positives (5.1%) and six false negatives (0.6%). Overall performance in determining susceptibility to nine antibiotics directly from urine was 10.5% true resistance, 82.4% true susceptibility, 5.3% false resistance and 1.8% false susceptibility. Using limited tests, the system correctly identified 80.7% of isolates, 11.8% could not be identified at all and 7.5% were incorrectly identified. In this study, MUS provided 94.7% of results in 24 h, compared to 78.4% produced by the conventional method. Thus, MUS proved an effective and efficient method for processing urines, saving significant time, materials and human resources.

Bacteria↗

Inactivation of the polyanionic detergent sodium polyanetholsulfonate by hemoglobin.

Sodium polyanetholsulfonate (SPS) has been added to blood culture media for many years. Its incorporation results in a higher yield of positive blood cultures due to its inactivation of antimicrobial cationic compounds. The most active of these cations include complement components, aminoglycoside-aminocyclitol antibiotics, and receptors on polymorphonuclear leukocytes. There have been reports from studies conducted outside patient blood culture bottles that SPS itself may possess antibacterial activity against some isolates of Neisseria meningitidis, Neisseria gonorrhoeae, and Peptostreptococcus anaerobius. Conversely, in patient clinical trials there has been no significant difference in pathogen isolation rates in the presence or absence of SPS. In an attempt to explain this in vitro/in vivo disparity, a search was undertaken to elucidate which variable constituent in blood, heretofore not studied quantitatively, might have a major effect on modulating the activity of SPS. It was found that hemoglobin combined stoichiometrically with SPS with a Kd of approximately 10(-7) mol/liter. Optimum SPS inactivation occurred at an SPS/hemoglobin ratio of 1:6 (wt/wt). SPS-sensitive isolates of N. gonorrhoeae and N. meningitidis were protected by the addition of hemoglobin from the antimicrobial effects of this polyanion in time-kill studies. This protection was directly related to the amount of SPS combined in solution. Therefore, the amount of free hemoglobin in solution must be measured when studying the antimicrobial activity of polyanions or when evaluating the effect of different polyanions on the recovery rates of pathogens in patient blood culture clinical trials.

Bacteriological Techniques↗

Bacterial isolates from neutropenic febrile pediatric patients and their sensitivity patterns to antibiotics.

Patients on cytotoxic therapy often develop neutropenia and fever. Our interest was to identify the common pathogens isolated from such patients and to study the sensitivity patterns of these organisms to the antibiotics used in their treatment. Thus, guidelines can be established by hospitals to identify which antibiotics can be used in the treatment of these patients when the results of cultures and sensitivities are not available. We conducted a retrospective study of neutropenic pediatrics presenting to AKUH from July, 1990 to June, 1996. A total of 153 isolates in 35 different patients were studied. Samples for culture were taken from the sites at risk. The majority of samples consisted of blood, stool, pus and urine. Twenty stool samples were also sent for microscopy. Malignancies were both hematological and non-hematological. Gram negatives were isolated in 52.9%, gram positives in 33.9% and parasites in 13.2%. Salmonella paratyphi B was the most commonly isolated organism, followed by Pseudomonas aeroginosa, Giardia lamblia was the most common parasite. Sensitivity patterns of these organisms to antibiotics studied showed that Escheria coli had the lowest sensitivity rate being only 40% sensitive to Aztreonam and 64% sensitive to Ofloxacillin. A comparison was made between our findings and those reported in literature, as well as the risk factors for developing neutropenia. A guide to management is also discussed.

Anti-Bacterial Agents↗

Nosocomial candidemia in non-neutropenic patients at an Italian tertiary care hospital.

In a retrospective study conducted in an Italian tertiary care hospital, the incidence of nosocomial candidemia was evaluated together with causative pathogens, treatment, and risk factors for death. Over a 6-year period (1992-1997), a total of 189 episodes of candidemia occurred in 189 patients (mean age 58+/-19 years), accounting for an average incidence of 1.14 episodes per 10,000 patient-days per year. The most common reasons for hospitalization were solid neoplasia (21%), trauma (17%), abdominal diseases requiring surgery (13%), and cardiovascular diseases (13%). No patient was neutropenic within 3 weeks prior to the onset of candidemia. One hundred thirty patients were hospitalized in intensive care units, 47 patients in surgical wards, and 12 patients in medical wards. Candida albicans was the most frequently isolated pathogen, accounting for 54% of fungal isolates, followed by Candida parapsilosis (23%), Candida glabrata (7%), Candida tropicalis (5%), Candida pelliculosa (4%), Candida lusitaniae (1%), Candida humicula (1%), and other non-albicans Candida spp. (5%). Seventy-six (41%) patients received adequate antifungal therapy. Seventy-one (58%) of the 123 evaluable patients with central venous catheters underwent line removal; 51 of them had catheter-related candidemia. The 30-day crude mortality rate was 45%. Older age, hospitalization in an intensive care unit, a longer duration of candidemia, retention of central lines, and inadequate antifungal therapy were significantly associated with poor outcome. In the present study, nosocomial candidemia was a frequent and relatively underestimated illness. Adequate antifungal therapy and central line removal independently reduced the high mortality of the disease.

Adolescent↗

Isolation and identification of anaerobic organisms from the male and female urogenital tracts.

Since Bacteroides spp may play an important role together with Gardnerella vaginalis in the pathogenesis of non-specific vaginitis and balanoposthitis, anaerobic organisms were isolated and identified from 34 female and 20 male patients attending a department of genitourinary medicine, and the results compared with the clinical findings and the presence of other routinely isolated pathogens. Twenty-three different organisms were recovered from 13 of the 20 men; of these organisms, 20 were of the Bacteroides spp. Most isolates were of the B melaninogenicus/oralis group, which forms part of the commensal vaginal flora in women. A definite association between the presence of anaerobes and other pathogens needs to be firmly established, as this obviously causes important complications in treating these conditions.

Bacteroides↗

Isolation and characterization of a cDNA encoding a plant defensin-like protein from roots of Norway spruce.

We are studying the interaction between the roots of Norway spruce seedlings (Picea abies L. Karst) and a highly pathogenic isolate of Pythium dimorphum. Here, we report the isolation of a cDNA from spruce roots encoding a protein with high sequence similarity to plant defensins, designated as SPI1 (Spruce Pathogen Induced No.1). The transcript hybridizing to the SPII cDNA probe is highly induced in uninfected roots when the seedlings are transferred from solid to liquid incubating malt medium (hypoxic conditions). However, when the seedlings are transferred from solid to liquid malt media containing a saturating amount of P. dimorphum hyphae, the amount of transcript is unchanged the first day after infection, but then decreases on day 1, and is no longer detectable 2 days after infection. Since plant defensins may play a role in plant defence, their negative regulation upon infection might reflect a strategy employed by this pathogenic fungus to evade the effect of toxic gene products.

Amino Acid Sequence↗

[Clinical experience with imipenem/cilastatin in the treatment of severe infections in general surgery].

In a prospective study 43 patients (19 men, 24 women) suffering from severe bacterial infections such as peritonitis (n = 16), soft tissue infection (n = 12), pneumonia (n = 7), septicemia (n = 6), catheter sepsis (n = 2), cholangitis (n = 4), osteomyelitis (n = 3), complicated urinary tract infection (n = 2) or endocarditis (n = 1) were treated t. i. d. with short-time i. v. infusions of 0.5 g imipenem/cilastatin for five to 37 days (means = 9). All the patients were cured or significantly improved following therapy with imipenem/cilastatin alone or in combination with surgical intervention. The most frequent isolates were Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus faecalis. 58 (83%) of the 70 pathogens isolated initially were eliminated. The 12 microorganisms (gram-negative aerobic bacteria) which persisted were non-contributory to the course of the infection and had MICs between 0.32 and 4 mg/l. The MICs for 60 isolates were less than or equal to 1 mg/l; the MICs for nine isolates were in the range of 2 to 8 mg/l. One S. epidermidis isolate presented primary resistance to imipenem (MIC 16 mg/l). The tolerability was good. Phlebitis was observed in one case only. Based on our experience we conclude that monotherapy with imipenem/cilastatin at a dosage of 0.5 g t. i. d. is appropriate for the treatment of severe bacterial infections.

Adolescent↗

Infective endocarditis at a hospital of the University of Kiel, 1958-1987.

The clinical courses of 214 patients with infective endocarditis treated between 1958 and 1987 at the First Medical Hospital of the University of Kiel (FRG) were analyzed retrospectively. A decrease in the incidence of endocarditis occurred during the 30-year observation period. The mean age of patients was 48 years, and men were more frequently affected than women. In the course of the investigation, a rise in isolated aortic valve disease was noted, whereas the number of patients with isolated involvement of the mitral valve and combined mitral-aortic valvular defects declined. Streptococci (57%) were the most frequent pathogens isolated; as opposed to their increase, the percentages of Staphylococcus aureus and enterococci decreased. Otolaryngological, dentogenic and urogenital diseases were most frequently held to be responsible for the development of infective endocarditis. Prior cardiosurgical interventions became increasingly significant as a cause of the disease. In this connection, a rising percentage of endocarditis cases was linked with prosthetically replaced heart valves. Complications and concomitant symptoms of endocarditis included the development of heart failure, cerebral embolism and encephalitis, splenomegaly, and renal inflammation. Finally, the marked decrease in mortality contrasted with a simultaneous rise in the number of endocarditis cases achieving full recovery.

Adolescent↗

Fulminant methicillin-sensitive Staphylococcus aureus infection in a healthy adolescent, highlighting 'Panton-Valentine leucocidin syndrome'.

A 14-year-old immunocompetent adolescent presented systemically unwell with left knee septic arthritis. Within several days, disseminated bone and soft tissue collections became evident, associated with deep venous thrombosis and pulmonary involvement. Methicillin-sensitive Staphylococcus aureus was isolated, harbouring Panton-Valentine leucocidin genes. Aggressive antibiotic and surgical therapies eventually lead to recovery. Intrafamilial spread of the pathogenic isolate was shown by household screening. This presentation is consistent with 'PVL Syndrome' and is typical of severe S. aureus infection emerging in young populations globally.

Adolescent↗

Therapy of serious skin and soft tissue infections with ofloxacin administered by intravenous and oral route.

We evaluated the safety and efficacy of ofloxacin administered both by the intravenous route and orally in 26 men with serious skin and soft tissue infection. Twenty-one patients completed antimicrobial therapy and were fully evaluable. Of these, 18 were judged to be cured, while 3 failed therapy either during or within 2 weeks after completion of therapy. Overall, Staphylococcus aureus was the most commonly isolated pathogen and was found to be susceptible to ofloxacin in 12 of 14 patients. Two patients, 1 with a tolerant isolate of S. aureus, the other patient with a resistant isolate of S. aureus, responded clinically to ofloxacin therapy; a third patient with an initially ofloxacin-sensitive isolate failed therapy, and on subsequent culture an ofloxacin-resistant S. aureus was isolated. Ofloxacin was well tolerated and efficacious in the treatment of skin and soft tissue infections including those caused by staphylococci and streptococci.

Administration, Oral↗

Enterotoxigenic Escherichia coli as cause of diarrhea among Mexican adults and US travelers in Mexico.

BACKGROUND: Enterotoxigenic Escherichia coli (ETEC) is the most common pathogen identified in travelers to Mexico with diarrhea. There have been few recent studies looking at the etiology of diarrhea in travelers compared with the local resident population. METHODS: We compared enteric pathogens isolated in two populations experiencing acute diarrhea acquired in Guadalajara, Mexico and also compared clinical illness caused by the principal pathogen, ETEC. RESULTS: A single and 2 enteropathogens were detected in 107 (23%) and 8 (2%), respectively, of 457 Mexicans in 1995 and 1997, and 37 (29%) and 2 (2%), respectively, of 127 US adults in 1997. The most common pathogen was ETEC in both groups (11% of Mexican, 19% of US adults), although more common in the US travelers group (p =.0017). Shigella spp and Cryptosporidium spp were less common in the Mexican (<1% and <1%, respectively) than in the travelers group (6% and 3%, respectively) (p <.001 and p =.002, respectively). Entamoeba histolytica was more often found in the Mexican group (4% Mexican, 0% US adults; p =.027). CONCLUSION: ETEC is the most common pathogen among travelers and Mexican residents in this study. The duration of untreated diarrhea due to ETEC was significantly shorter among Mexicans (49 hours in Mexican, 94 hours in US adults; p =.0004), as was the average number of unformed stools passed over 4 days (Mexicans 8.8 versus travelers 17.9 stools; p =.0009

Adult↗

[The impact of antibiotic use on hospital-acquired pneumonia: data of etiology tests].

AIM OF THE STUDY: To investigate most common pathogens isolated from the hospital-acquired pneumonia patients bronchoalveolar lavage fluid in Kaunas University of Medicine Hospital according to the previous antibiotic use and to estimate pathogens antibacterial susceptibility. MATERIALS AND METHODS: Results of 87 hospital-acquired pneumonia patients bronchoalveolar lavage fluid quantitative cultures were analyzed. Microorganisms isolated in clinically significant amount were considered as the etiological agents and included into analysis. Susceptibility was tested using the standard methods. Previously untreated patients were considered if the antibacterials were not administered at all or were used less than for 24 hours. RESULTS: H. influenzae isolation in significant amount rates were higher in previously untreated patients group comparing to previously treated (29.2%. (n=14) and 5.1% (n=2), respectively, p<0.05). Non-fermenters (P. aeruginosa and Acinetobacter spp.) isolation rates were higher in those previously treated comparing to untreated patients - (31.0% (n=13) and 4.2% (n=2), respectively, p<0.05). All H. influenzae strains were susceptible to ampicillin and cefuroxime. 22.2-44.4% of P. aeruginosa strains were resistant to ceftazidime, amikacin and ciprofloxacin. Estimated Acinetobacter spp. resistance to ciprofloxacin and gentamycin was 83.3% and to ampicillin/sulbactam - 16.7%. All methicillin-susceptible S.aureus were also susceptible to gentamycin and fucidin and methicillin resistant to rifampicin and vancomycin. CONCLUSIONS: Previous antibiotic treatment has an impact on pneumonia etiology testing. H. influenzae strains are more common isolated hospital-acquired pneumonia etiologic agents in previously untreated patients. The low antibacterial resistance was found enabling the use of aminopenicillins for treatment if H. influenzae infection suggested. The use of antibacterials increases non-fermenters isolation rates and combined antipseudomonal treatment is reasonable in these patients.

Acinetobacter↗

[Susceptibility of bacteria isolated from lower respiratory tract infections to antibiotics (1983)].

Bacterial isolates from the patients with pulmonary infections have been collected over these 3 years, in collaboration with investigators at 13 hospitals in various parts of Japan for the study on frequency of isolation of pathogens among the patients and their drug susceptibilities. Possible causative pathogens mainly isolated from sputum in patients with lower respiratory tract infections during period from September 1983 to March 1984, were collected. The frequency of bacterial isolates from the sputum and their drug susceptibility on H. influenzae among the various pathogens are discussed. The kinds of bacterial species isolated from the patients with respiratory tract infections associated with chronic bronchitis, chronic capillary bronchitis or bronchiectasis and their relative frequency of isolation were as follows; Total numbers of bacterial isolates collected from various hospitals were 220 strains in 1981, 168 strains 1982 and 258 strains in 1983. H. influenzae was always isolated with highest frequency of 50.5% in 1981, 45.8% in 1982 and 40.7% in 1983, and followed by P. aeruginosa (24.1%), S. aureus (8.2%), S. pneumoniae (7.3%) and K. pneumoniae (5.9%) and E. coli (4.1%) in 1981; P. aeruginosa (30.4%), S. pneumoniae (11.9%), S. aureus (4.8%), K. pneumoniae (3.0%) and E. coli (1.8%) in 1982; P. aeruginosa (26.7%), S. pneumoniae (10.1%), S. aureus (7.8%), K. pneumoniae (3.5%) and E. coli (3.5%) in 1983. The drug susceptibility test of H. influenzae to ampicillin (ABPC), piperacillin (PIPC), mezlocillin (MZPC), sulbenicillin (SBPC), gentamicin (GM), amikacin (AMK), cefotiam (CTM), cefmetazole (CMZ), cefoperazone (CPZ), cefotaxime (CTX), ceftizoxime (CZX), cefmenoxime (CMX) and latamoxef (LMOX) was done by using agar micro-broth dilution methods. H. influenzae was most markedly susceptible to cephems of the third generation, especially to CMX, CZX and CTX by which about 95% of H. influenzae tested were inhibited the growth under the concentration with less than or equal to 0.10 microgram/ml of the drugs. Furthermore, annual changes in susceptibility of H. influenzae to various antibiotics was analyzed over the period from 1981 to 1983. The frequency of S. pneumoniae isolated from patients with chronic bronchitis or bronchiectasis was about 10% in this survey. However, in the case of respiratory infections associated with bacterial pneumonia, the frequencies were as follows; 24.8% (77 cases/311 cases) in 1981, 17.7% (44 cases/248 cases) in 1982, and 11.0% (39 cases/355 cases) in 1983. The frequency of isolation of S. pneumoniae decreased every year.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

[Two cases of Trichophyton mentagrophytes infection contracted from a hamster and a chinchilla].

We report two cases of Trichophyton mentagrophytes infection. Case 1: A 10-year-old girl visited Tokyo Electric Power Hospital in June 1994 for evaluation of an erythematous lesion on her head. Three months of topical steroid therapy exacerbated the lesion with pustular formation. Histopathological and mycological examination revealed that the patient had tinea capitis caused by T. mentagrophytes. T. mentagrophytes was also isolated from her pet, a hamster. Case 2: A-14-year-old girl was referred to Shonan Clinic in January 1996 with scaly erythema on her face. She had been treated with neticonazole hydrochloride at another clinic, but the lesion became worse. Direct microscopic examination of the scale was negative at that time, so treatment with topical steroid was started. After 10 days, the lesion was almost cured, but one month later it recurred with an annular distribution. KOH preparation of the scale revealed mycelia and T. mentagrophytes was isolated on culture. T. mentagrophytes was also isolated from her pet, a chinchilla. In both cases, the oral administration of itraconazole at 50 mg/day was effective. The isolated pathogen was identified as Arthroderma vanbreuseghemii with species-specific primers of chitin synthase 1 gene. T. mentagrophytes is one of the most common dermatophytes isolated from man and animals. Rodents like the hamster and the chinchilla have recently become popular as pets in Japan. We should be aware that rodents may carry this kind of fungal pathogen as they become even more popular as pets.

Adolescent↗

Efficacy/safety of amoxicillin/clavulanate in adults with bacterial rhinosinusitis.

PURPOSE: Acute bacterial rhinosinusitis (ABRS) is a common and uncomfortable condition, frequently caused by Streptococcus pneumoniae or Haemophilus influenzae. Antibacterial resistance among these and other common respiratory pathogens is now widespread and of concern. Pharmacokinetically enhanced amoxicillin/clavulanate 2000/125 mg was developed to be effective against the common respiratory pathogens, including many resistant strains. MATERIALS AND METHODS: This open-label, noncomparative study assessed the bacteriologic and clinical efficacy of amoxicillin/clavulanate 2000/125 mg in adult patients with ABRS. Requirements for study entry included a clinical diagnosis of ABRS supported by radiologic findings. In addition, sinus puncture for bacteriologic assessment was required at study entry. RESULTS: Overall, bacteriologic success (eradication or clinical evidence of eradication) at the follow-up visit (days 17-28) was achieved in 87.8% (722/822) of patients with 1 or more pathogen isolated at screening, in 93.2% (246/264) of patients with S pneumoniae, in 96.7% (29/30) of those with penicillin-resistant S pneumoniae (penicillin minimum inhibitory concentrations >or=2 microg/mL), and in 88.7% (110/124) of patients with beta-lactamase-positive pathogens. Bacteriologic success was achieved against 6 of 7 S pneumoniae isolates with amoxicillin/clavulanic acid minimum inhibitory concentrations of 4/2 microg/mL or higher. CONCLUSIONS: Amoxicillin/clavulanate 2000/125 mg was generally well tolerated. This new amoxicillin/clavulanate formulation provides a suitable option for empiric therapy for ABRS in adults.

Adolescent↗

Characterization and detection of plant trypanosomatids by sequence analysis of the small subunit ribosomal RNA gene.

The complete sequences of the genomic small subunit ribosomal RNA gene from two Phytomonas isolates: one associated with palm pathologies (P. cocos FGuiana) and one found in lactiferous plants with no apparent pathology (P. Euphorbe Senegal), were analyzed. Partial sequences from a number of other Phytomonas isolates were also determined. The sequences obtained were used to determine the phylogenetic relationships between Phytomonas and other trypanosomatids as well as within the genus Phytomonas. The analysis showed that the intraphloemic isolates associated with pathologies in palm trees formed a homogeneous group that diverged from the more heterogeneous group of non-pathogenic isolates found in latex plant. Sequence comparisons of the full and partial SSU rRNA gene, identified sequences which are specific to the genus Phytomonas and an EcoRI restriction nuclease site which specifically identifies the Phytomonas isolates associated with diseases in palm trees.

Animals↗