Microbiological Specimens Research Articles

Pulmonary Manifestations of Malaria

Lung involvement in malaria has been recognized for more than 200 hundred years, yet our knowledge of its pathogenesis and management is limited. Pulmonary edema is the most severe form of lung involvement. Increased alveolar capillary permeability leading to intravascular fluid loss into the lungs is the main pathophysiologic mechanism. This defines malaria as another cause of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS).Pulmonary edema has been described most often in non-immune individuals with Plasmodium falciparum infections as part of a severe systemic illness or as the main feature of acute malaria. P.vivax and P.ovale have also rarely caused pulmonary edema.Clinically, patients usually present with acute breathlessness that can rapidly progress to respiratory failure either at disease presentation or, interestingly, after treatment when clinical improvement is taking place and the parasitemia is falling. Pregnant women are particularly prone to developing pulmonary edema. Optimal management of malaria-induced ALI/ARDS includes early recognition and diagnosis. Malaria must always be suspected in a returning traveler or a visitor from a malaria-endemic country with an acute febrile illness. Slide microscopy and/or the use of rapid antigen tests are standard diagnostic tools. Malaria must be treated with effective drugs, but current choices are few: e.g. parenteral artemisinins, intravenous quinine or quinidine (in the US only). A recent trial in adults has shown that intravenous artesunate reduces severe malaria mortality by a third compared with adults treated with intravenous quinine. Respiratory compromise should be managed on its merits and may require mechanical ventilation.Patients should be managed in an intensive care unit and particular attention should be paid to the energetic management of other severe malaria complications, notably coma and acute renal failure. ALI/ARDS may also be related to a coincidental bacterial sepsis that may not be clinically obvious. Clinicians should employ a low threshold for starting broad spectrum antibacterials in such patients, after taking pertinent microbiologic specimens. Despite optimal management, the prognosis of severe malaria with ARDS is poor.ALI/ARDS in pediatric malaria appears to be rare. However, falciparum malaria with severe metabolic acidosis or acute pulmonary edema may present with a clinical picture of pneumonia, i.e. with tachypnea, intercostal recession, wheeze or inspiratory crepitations. This results in diagnostic confusion and suboptimal treatment. Whilst this is increasingly being recognized in malaria-endemic countries, clinicians in temperate zones should be aware that malaria may be a possible cause of 'pneumonia' in a visiting or returning child.

ORIGINAL RESEARCH—EJACULATORY DISORDERS: Chronic Prostatitis in Premature Ejaculation: A Cohort Study in 153 Men

Premature ejaculation is a common male sexual dysfunction, affecting 30-40% of sexually active men in an age-dependent manner. Chronic prostatitis has been suggested as an important organic cause of premature ejaculation. The aim of this study was to confirm previous data reported on the incidence of chronic prostatitis in a large cohort of patients with primary and secondary premature ejaculation. A total of 153 consecutive heterosexual men aged 29-51 years with premature ejaculation and another 100 male healthy subjects were included in this study. Sequential microbiologic specimens were obtained according to the standardized Meares and Stamey protocol. Nonbacterial prostatitis was defined by the evidence of prostatic inflammation but negative cultures of urine and prostatic fluids in men with various genitourinary symptoms. There was no significant difference between patients and control subjects regarding age, education, or intercourse frequency. Prostatic inflammation was found in 64% and chronic bacterial prostatitis in 52% of the patients with premature ejaculation, respectively, showing statistical significance compared with control subjects (P < 0.05). Results in our study showed a high prevalence of chronic prostatitis in patients with premature ejaculation. Examination of the prostate, physically and microbiologically, should be considered during assessment of patients with premature ejaculation.

Tobramycin-impregnated Calcium Sulfate Prevents Infection in Contaminated Wounds

Open fractures often are associated with increased rates of infection and nonunion, multiple surgical procedures, and delayed return to preinjury activity. Antimicrobial bone graft substitutes used as an alternative to antibiotic cement beads and/or delayed autologous bone grafting may provide a useful adjunct in patients with open fractures. A stable, unicortical defect was created and contaminated with 30 microL of 5 x 10 colony-forming units/mL of Staphylococcus aureus in the proximal tibial metaphysis of Spanish goats. The negative control group received no treatment, the carrier group received synthetic bone graft alone, the positive control group received tobramycin antibiotic cement, and the treatment group received tobramycin antimicrobial synthetic bone graft (calcium sulfate). After a 3-week evaluation period, intraosseous microbiologic specimens were obtained. The Staphylococcus aureus contaminant was recovered in 11 of 12 animals (mean = 6.9 x 10 colony-forming units/g marrow) in the negative control group and in all animals (mean = 2.2 x 10 colony-forming units/g marrow) in the carrier group. Bacteria were not found in the antibiotic-treated groups. The tobramycin-impregnated calcium sulfate was effective in preventing infection in a contaminated defect. It could be beneficial in reducing the number of surgeries and recovery time because it is bioabsorbable and osteoconductive.

Crisis management during anaesthesia: sepsis

Background: Anaesthesia with concurrent sepsis is risky, and involves consideration of possible organ dysfunctions—respiratory, cardiovascular, renal, and haematological—as well as ensuring that appropriate antibiotics are given after taking the necessary...

Assessing microbiology test orders and specimen quality

The clinical utility of microbiology culture results is directly related to the types of specimens submitted for culture and theirquality. The identification and handling of clinically irrelevant or sub-optimal test orders, assessment of specimen quality, and direct Gram stain interpretation and reporting of microorganisms are reviewed. Test requests that can generate clinically misleading information are outlined.

Device-Related Infections: A Review

The use of surgically implanted devices has increased as a result of their beneficial effect on quality of life, and in some circumstances, on patient survival rates. They can, however, be associated with a variety of complications, the most dreaded being infection. Device-related infections are important to understand because of the morbidity and mortality associated with them. Frequently, patients are managed with hospitalization, prolonged courses of antibiotics, and surgical interventions, all of which can negatively impact on patients' quality of life. Such care is also associated with increased costs to health care systems. Furthermore, these infections often represent a diagnostic challenge because of the lack of consensus definition of what constitutes an infection and its severity, as well as the paucity of well-designed, large studies addressing optimal methods of investigation and management. An implant-associated infection is defined as a host immune response to one or more microbial pathogens on an indwelling implant. An understanding of the pathogenesis of these infections provides a rationale for management. Development of device-related infections begins with colonization of the foreign material, followed by a complex metamorphosis by the microorganisms with resultant biofilm formation. In this surface-associated form, bacteria have altered phenotypic properties. This change, in conjunction with the physical protective layer provided by the biofilm, renders antimicrobial therapy ineffective when used alone. Because the microorganisms are able to reside on the hardware, they proliferate and cause local damage, such as loosening of implanted devices, wound dehiscence, or disruption of prosthetic valves, as well as systemic manifestations, such as fever or embolic phenomenon. The onset and clinical manifestations of device-related infections vary with the pathogen involved, as well as which component of the device is affected. The time period after device implantation that signs and symptoms develop can assist in the selection of empiric antimicrobial therapy. Optimal diagnostic microbiologic specimens are paramount in tailoring the antimicrobial therapy, which almost always has to be given for a prolonged period of time. Surgical removal of the device is usually necessary. Some studies of limited types of device-related infections, however, have defined indications for which salvage therapy may be warranted. In addition, some patients are not candidates for, or may not want, further surgical interventions, in which case indefinite suppressive antimicrobial therapy may be considered. This review provides an overview of infections related to various neurosurgical, cardiac, and orthopedic devices, as well as those related to cochlear, breast, and penile prostheses, with discussion of definitions of such infections, along with microbiology, pathogenesis, and management guidelines, including the limited indications for salvage techniques.

Diabetic foot ulcer and multidrug-resistant organisms: risk factors and impact.

The primary objective was to characterize factors allowing the colonization of diabetic foot wounds by multidrug-resistant organisms (MDRO), and the secondary objective was to evaluate the influence of MDRO colonization/infection on wound healing. In 180 patients admitted to a specialized diabetic foot unit, microbiological specimens were taken on admission. Potential risk factors for MDRO-positive specimens were examined using univariate and multivariate analyses. Prospective follow-up data from 75 patients were used to evaluate the influence of MDRO colonization/infection on time to healing. Eighteen per cent of admission specimens were positive for MDRO. MDRO-positive status was not associated with patient characteristics (age, sex, type of diabetes, complications of diabetes), wound duration, or wound type (neuropathic or ischaemic). In the multivariate analysis, the only factors significantly associated with positive MDRO status on admission were a history of previous hospitalization for the same wound (21/32 compared with 48/148; P = 0.0008) or the presence of osteomyelitis (22/32 compared with 71/148; P = 0.025). In the longitudinal study of 75 wounds, MDRO-positive status on admission or during follow-up (6 months at least or until healing, mean 9 +/- 7 months) was not associated with time to healing (P = 0.71). MDROs are often present in severe diabetic foot wounds. About one-third of patients with a history of previous hospitalization for the same wound, and 25% of patients with osteomyelitis, had MDRO-positive specimens. This suggests that hygiene measures, or isolation precautions in the case of admission of patients presenting with these characteristics, should be aggressively implemented to prevent cross-transmission. Positive MDRO status is not associated with a longer time to healing.

Mandatory Hygiene Control As a Key of Decreasing Failures of Endoscope Reprocessing in Ambulatory Care

Introduction: Preceding investigations of quality of hygiene of endoscope disinfection showed a failure in 50%(1) to 60%(2) in ambulatory settings. Mandatory hygiene control and certification for ambulatory endoscopy centers were introduced thereafter. The comparison of microbiological testing results before and after the introduction of hygiene controls are presented.Methods: In the first study (1) all ambulatory endoscopy centers (aec) were invited to participate in a hygiene control study, voluntarily. In the following study(2) all endoscopists applying for reimbursement of colonoscopy had to have undergo a hygiene control, performed by authorised microbiological laboratories as in (1) . Methods of endoscope reprocessing (automatically-chemo-thermal (act), semi-automatically (sa) and manually (m)) were documented. Microbiological specimens were taken from distal end, working channel, air-water channel of the endoscopes after reprocessing and the water rinse system. Identification of bacterial count > 10 CFU/ml and/or culture of E. coli, Enterobacter (EB), Enterococci (E), P. aeruginosa (PA) or other non fermenting gram- rods (NFG) in the endoscope channel flushing fluid were considered as failures.Results: In the (1) study 1271 endoscopes (52% gastroscopes (g), 40% colonoscopies (c), 7% duodenoscopes (d)) in 577 endoscopy centers were investigated. Bacterial contamination after disinfection were shown in 75% (498/661), 74% (n=380/513) and 55% (n=54/97) of g, c and d tested, respectively. In the (2) study 1170 endoscopes (45% g, 57% c, 7% d) of 592 aecs were investigated. 79/1170 (6,7%) endoscopes (6% (n=31/494) g, 9% (n=47/519) c, 1,2% (1/81) d) showed bacterial contamination. Comparing to the preceding results, the contamination of g (75% vs 6%), c (74% vs 9%) and d (55% vs 1,2%) decreased clearly . The methods for reprocessing applied differed (act 25% vs 56,6%, sa 21% vs 16,7%, m 53% vs 26.6%) between study 1 and 2. Different rates of successful reprocessing of endoscopes (84% vs 97% act, 60% vs 81% sa, 56% vs 87% m) were shown as well. Conclusion: The introduction of a mandatory hygiene control measurement may have caused an increasing implementation of act reprocessing. Consequently the failure rates decreased clearly. In order to avoid the risk of nosocomial infection by gi endoscopes it is advisable to implement mandatory hygiene control. (1)L. Bader, G. Blumenstock, B. Birkner et al. Z Gastroenterol 2002;40:157 (2) Birkner B, G. Blumenstock, A Munte et al. JCHAO. Chicago, Oct 2003.

Analysis of Microbiological Culture Specimens in Shree Birendra Hospital, Chhauni

Analysis of Microbiological Culture Specimens in Shree Birendra Hospital, Chhauni

Emergence of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infection in Queensland, Australia

Objectives: To investigate the incidence and epidemiology of non-multiresistant methicillin-resistant Staphylococcus aureus (nmMRSA) infection in south-east Queensland, Australia. Study design: A retrospective survey was done of hospital records of all patients who had non-multiresistant MRSA isolated at Ipswich Hospital (a 250-bed general hospital, 40 km south-west of Brisbane, Queensland, Australia) between March 2000 and June 2001. Laboratory typing of these isolates was done with antibiogram, pulsed-field gel electrophoresis, bacteriophage typing and coagulase gene typing. Results: There were 44 infections caused by nmMRSA. Seventeen infections (39%) occurred in patients from the south-west Pacific Islands (predominantly Samoa, Tonga and New Zealand). Laboratory typing showed that the isolates in Pacific Islanders were Pacific Island strains, and 16/17 of these infections were community acquired. Twenty-three infections (52%) occurred in Caucasians. Eleven of the isolates from Caucasians (48%) were a new predominantly community-acquired strain that we have termed the ‘R’ pulsotype, nine (39%) were Pacific Island strains, and three (13%) were health care institution-associated strains. Four infections occurred in patients who were not Caucasians or Pacific Islanders. Overall, 34 of all 44 infections (77%) were community' acquired. Conclusions: Non-multiresistant MRSA infection, relatively frequently observed in Pacific Islanders in south-east Queensland, is now a risk for Caucasians as well, and is usually community acquired. Clinicians should consider taking microbiological specimens for culture and antimicrobial susceptibility testing in patients with suspected staphylococcal infections who are not responding to empirical therapy with β-lactam antibiotics.

Management of infected shoulder replacement.

The purpose of the present work is to present treatment options and our own results for patients with infected shoulder alloarthroplasties. Twelve patients with an infected shoulder replacement were treated. Their age ranged from 56 to 82 years. Indications for surgical revision were clinical symptoms compatible with an infection or positive serologic tests, especially an elevated C-reactive protein. Aspirated intra-articular fluid with a white blood cell count above 30,000 or positive for bacterial growth was also an important diagnostic feature. Retrospective analysis differentiated three groups with three different treatment regimens. Group 1 with early infection but without soft-tissue involvement (n=1): this particular patient underwent arthroscopic synovectomy. Group 2 with early infection and soft-tissue involvement within 4 weeks after index surgery (n=1): this patient underwent open synovectomy. The largest group was group 3 with late infection (n=10): these patients were treated with two-stage revision and a temporary spacer. The time between explantation and reimplantation ranged between 4 weeks and 6 months. With the temporary spacer, an anatomically stable condition could be established for all patients, and reconstruction of the humeral length even in long implants was possible. All patients underwent physiotherapy with the temporary spacer in place. A positive intraoperative microbiologic specimen was only found in 4 patients. In both group 1 and 2 patients, the infection healed, and thus the original implant could be kept in situ. In 8 patients, the temporary spacer was removed and exchanged for a regular implant. The postoperative raw Constant score at the time of the last follow-up examination was 48, due mainly to a loss of motion and power. All shoulders were stable, and the elbow function was good. Use of an antibiotic-loaded spacer allows successful treatment of infected shoulder replacements.

Costing a major hospital outbreak of gastroenteritis due to Norovirus (Norwalk-like virus)

O utbreaks of Norovirus infection in hospitals are common, but the financial impact is often poorly defined. Following a major outbreak, we propose a simple costing system. The key cost drivers identified were: 1. Lost bed days (LBDs) and cancelled elective surgical operations. The cost of an occupied or closed bed was £204 per day; 2. The period of staff sickness, estimated at an average of four days. Staff costs were estimated at £79.45 per day; 3. The employment of additional nurses; 4. Environmental cleaning (£200 per ward); 5. Additional microbiology costs (£8.27 per sample); 6. Ward consumable costs, estimated at £5 per ward per day. The outbreak involved 16 wards, affecting 139 patients and 124 staff (mainly nurses) over a two week period. LBDs due to inpatient sickness amounted to £85,068. Lost days due to staff sickness cost £39,407. 150 cancelled surgical operations equates with 525 LBDs, costing £107,100. The cost of employing additional nursing staff was £41,465. Further costs included £3,200 for 16 ‘deep cleans', £560 for ward consumables, £1,150 for microbiology specimens and £1,165 for additional infection control hours. The total cost of the outbreak was estimated at £279,115. The costing model described quickly identified key financial pressures and could be applicable to other Norovirus outbreaks.

Gram Stain, Culture, and Histopathological Examination Findings for Heart Valves Removed because of Infective Endocarditis

Retrospective chart review was undertaken for 480 patients who underwent a total of 506 valve replacements or repair procedures for infective endocarditis. The influence of preoperative antimicrobial treatment on culture, Gram stain, and histopathological examination findings for resected valve specimens was examined. When valves were removed before the end of treatment, organisms were seen on the Gram stain of ground valve material performed in the microbiology laboratory and on Gram-stained histopathological sections in 231 (81%) of 285 and 140 (67%) of 208 specimens, respectively (P=.0007). Gram-positive cocci were either cultured from or observed in excised valve tissue in 42 (67%) of 63 episodes involving negative preoperative blood cultures. Positive Gram stain results for microbiological specimens should be reintroduced into the definite pathological criteria for infective endocarditis. When deciding on how long to continue antimicrobial therapy after valve replacement for endocarditis, valve culture results should be the only laboratory finding taken into account, because it takes months for dead bacteria to be removed from sterile vegetations.

A clinicopathological review of 34 cases of inflammatory breast disease showing an association between corynebacteria infection and granulomatous mastitis

Granulomatous mastitis is a rare condition of unknown aetiology. The great majority of cases has not been associated with bacterial pathogens if women with mammary tuberculosis are excluded. We noted that some women in Auckland with a histological diagnosis of granulomatous mastitis had both microbiological and histological evidence of corynebacteria infection and aimed to study this further. Thirty-four women were reviewed who presented with inflammatory breast disease and had microbiological specimens from which corynebacteria were isolated and/or histological specimens containing coryneform bacteria. These 34 cases were compared with 28 controls with similar histology but no evidence of corynebacteria infection. Twenty-seven (79%) of the cases and 21 (75%) of the controls had histological and/or cytological evidence of suppurative granulomas. Fourteen of the 34 cases also had Gram-positive bacilli (GPB), recognisable as coryneform bacteria, in histological sections. In all cases the bacilli were confined to empty spaces, consistent with dissolved lipid, and were surrounded by neutrophils and, frequently, suppurative granulomas. Corynebacterium species were isolated from 52 of 116 microbiological specimens taken from the 34 cases. Forty of these 52 cultures were pure. Twenty-four of the cultures were further classified biochemically and using 16S rRNA gene sequencing. Twenty of the 24 were lipophilic Corynebacterium species and 14 were identified as Corynebacterium kroppenstedtii. The cases were more likely to present with fever or neutrophilia and more often formed sinuses than the controls but other clinical features were similar. Maori and Pacific Islanders accounted for 77% of the women across both groups. We suggest granulomatous mastitis can be associated with corynebacteria infection, particularly infection by C. kroppenstedtii. The significance of this finding, which has previously been described in only a single case report, is discussed.

Gatifloxacin Phase IV surveillance trial (TeqCES Study) utilizing 5000 primary care physician practices: report of pathogens isolated and susceptibility patterns in community-acquired respiratory tract infections

Recently FDA-approved fluoroquinolones like gatifloxacin possess enhanced activity against Gram-positive pathogens such as Streptococcus pneumoniae. However, experience with adverse events among previously used fluoroquinolones has led to expanded post-marketing investigations of clinical efficacy and safety. An open-label gatifloxacin trial was initiated in early 2000, using 2795 (>15,000 enrolled cases) primary care providers for treatment of community-acquired respiratory tract infections (CARTI) such as community-acquired pneumonia (CAP), acute bacterial exacerbation of chronic bronchitis (ABECB), acute sinusitis. Microbiology specimens and sputum slides were referred to a reference laboratory, pathogens identified and reference antimicrobial susceptibility tests performed. Results were classified by infection site, geographic census region and patient profile/demographics. The most frequent pathogens were: for CAP ( n = 384)- S. pneumoniae (37%) > Hemophilus influenzae (31%) > Moraxella catarrhalis (13%); for ABECB (528)- H. influenzae (37%) > M. catarrhalis (26%) > S. pneumoniae (17%); and for sinusitis (2691)- M. catarrhalis (29%) > H. influenzae (24%) > S. pneumoniae (17%). H. parainfluenzae (ABECB) and S. aureus (sinusitis) were also commonly isolated. CAP S. pneumoniae isolates had significantly less high-level resistance (5% at ≥2 μg/ml) than those isolates from ABECB or sinusitis (13–15%). United States census zone differences in S. pneumoniae resistance were identified (greatest in West or East South Central, South Atlantic). S. pneumoniae macrolide resistance was high (23–33%) and H. influenzae clarithromycin susceptibility was only 56–62%. β-lactamase rates in H. influenzae and M. catarrhalis were 21–29% and 88–92%, respectively. Only one S. pneumoniae was not susceptible to gatifloxacin, and this new fluoroquinolone was fourfold more potent than levofloxacin (MIC 50, 0.25 vs. 1 μg/ml). This Phase IV surveillance trial (TeqCES) confirmed the clinical importance of S. pneumoniae, H. influenzae and M. catarrhalis in CARTI, and high fluoroquinolone potency/spectrum (>97% susceptible). β-lactams and macrolides continue to be compromised by increasing resistances in pathogens isolated in these monitored primary care settings.

Microbiology of acute otitis externa.

To isolate and characterize bacteria and fungi from acute otitis externa (AOE) and to obtain susceptibility profiles on each bacterial isolate. Prospective core series. Specimens were collected from the external canals of subjects with clinically diagnosed acute otitis externa. Species-level identification for each bacterial isolate recovered was obtained by combining phenotypic and genotypic data. End point mean inhibitory concentration (MIC) testing was performed using National Committee for Clinical Laboratory Standards (NCCLS) recommended methods. In Alcon-sponsored clinical studies conducted in 1998 to 2000, microbiology specimens were collected from 2039 subjects (2240 diseased ears) by 101 investigators throughout the United States. A total of 2838 bacteria, 32 yeast, and 17 molds were recovered from 2048 ears clinically diagnosed as acute otitis externa. Of the 202 bacterial species recovered, the species most frequently isolated was Pseudomonas aeruginosa (38%). The next 10 species most frequently isolated were: Staphylococcus epidermidis, 9.1%; Staphylococcus aureus, 7.8%; Microbacterium otitidis, 6.6%; Microbacterium alconae, 2.9%; Staphylococcus caprae, 2.6%; Staphylococcus auricularis, 2.0%; Enterococcus faecalis, 1.9%; Enterobacter cloacae, 1.6%; Staphylococcus capitis subsp. Ureolyticus,1.4%; and Staphylococcus haemolyticus, 1.3%. Susceptibility profiles of S. epidermidis isolates revealed the greatest frequency of high-level resistance to selected antibiotics (>/=8 microg/mL): 23%, neomycin-resistant; 11%, oxacillin-resistant; and 12%, ofloxacin-resistant. Susceptibility profiles of S. aureus isolates revealed a lower frequency of high-level resistance: 6.3%, neomycin-resistant; 2.7%, oxacillin-resistant; and 4.5%, ofloxacin-resistant. P. aeruginosa with high-level resistance to quinolones (>/=128 mcg/mL for ofloxacin) was recovered from only 1 subject. Likewise, resistance of P. aeruginosa to aminoglycosides was rare. Twenty isolates had neomycin MICs >/=64 mcg/mL and 10 isolates had gentamicin MICs >/=16 mcg/mL. The coryneform isolates identified as Microbacterium otitidis had an intrinsic lack of susceptibility to quinolones (ofloxacin MICs >/=16 mcg/mL) and aminoglycosides (tobramycin MICs >/=32 mcg/mL and gentamicin MICs >/=8 mcg/mL). Bacterial infections of the external ear canal are most often caused by P. aeruginosa. However, there are a great number of other gram-positive and gram-negative bacterial species that are recovered from patients with acute otitis externa. Because of this diverse etiology, the best topical therapeutic choice for topical therapy is for the most potent, broad-spectrum (especially anti-P. aeruginosa) antibiotic available.

Mikrobiologische und histomorphometrische Untersuchung von Knochen-Pin-Interfaces in Fixateur externes verschiedenen Materials - Experimentelle Studie mit Schafen -

Ziel: Untersuchung der Pin-Knochen-Integration und der bakteriellen Kontamination von Fixateur-externe-Pins gleicher geometrischer Form, jedoch unterschiedlichen Materials (rostfreier Stahl, Titan und rostfreier Stahl mit Silberbeschichtung). Studiendesign: Wir teilten 18 Schafe (30 - 45 kg) in 3 Gruppen auf, um die oben genannten Charakteristika der Beziehung zwischen Pin und Knochen zu untersuchen. In histomorphometrischen Untersuchungen wurden die prozentualen Anteile von kortikalem und spongiösem Knochen sowie die Größe der Kontaktfläche zwischen Pin und Knochen bestimmt. Die mikrobiologischen Proben wurden am Eintrittspunkt des Pins im Knochen und an der Pinspitze entnommen. Ergebnisse: Die höchste Anzahl von Bakterien wurde auf der Oberfläche der silberbeschichteten Pins gefunden, der Ort der stärksten bakteriellen Kontamination war der Eintrittspunkt des Pins im spongiösen Knochen. Die histomorphometrische Untersuchung zeigte, dass die Pins mit der größten Kontaktfläche mit dem Knochen diejenigen aus Titan waren, gefolgt von den Stahlpins und schließlich den silberbeschichteten Pins. Schlussfolgerungen: Die Silberbeschichtung verhindert nicht die Ausbildung von bakterieller Flora, das Ausmaß der Kontamination war statistisch signifikant größer als inden anderen beiden Gruppen. Auch bezüglich der Integrationin den Knochen waren die Ergebnisse der Titan- und Stahlpins besser, wobei die Position des Pins im Knochen keine Rolle spielte.

Clonality of Black-pigmented Anaerobes Isolated from Infected Root Canals and Subgingival Plaque in 12 Patients.

The purpose of this study was to investigate the clonal types of black-pigmented anaerobes isolated from infected root canals and subgingival plaque. Twelve patients, who had single-rooted teeth with selected chronic apical periodontitis and had not undergone endodontic treatment, were chosen for thisstudy. Microbiological specimens from the root canals were collected with three sizes of H-files, and thosefrom six subgingival sites of the same teeth were collected with paper points. The isolates were identified by the 16S rRNA gene-directed PCR method, and the gene types were determined by the arbitrarily primed PCR (AP-PCR) method. Porphyromonas gingivalis and Prevotella nigrescens were the most frequently isolated species from the root canals (41.7%) and from subgingival plaque samples (50.0%) in 12 patients, respectively. Four patients simultaneously harbored the same species in the root canal and subgingival plaque (three patients harbored P. nigrescens and one patient P. gingivalis). The AP-PCR patterns of isolates from the root canal and subgingival plaque were identical in at least three out of 12 patients. These results support the hypothesis that the pocket is one of the possible sources of root-canal infection.

Role of serial routine microbiologic culture results in the initial management of ventilator-associated pneumonia.

Results of routine microbiologic cultures of specimens obtained before the onset of ventilator-associated pneumonia (VAP) in intensive care unit (ICU) patients might help to identify the causative microorganisms and thus to select effective initial antimicrobial therapy. To test this hypothesis, we prospectively studied 125 consecutive VAP episodes for which the causative microorganisms were determined using bronchoscopic techniques. Upon entry into the study, each patient's hospital chart was reviewed and culture results of all previously obtained microbiologic specimens were recorded (mean number +/- SD per patient, 45 +/- 38). A total of 220 microorganisms were cultured at significant concentrations (> or = 10(3)/10(4) colony-forming units [cfu]/ml) from bronchoscopic specimens and considered responsible for pneumonia. Of these 220 organisms, only 73 (33%) were recovered before VAP onset, sometimes from multiple sites in the same patient but mainly from prior respiratory secretion cultures (n = 53). Also previously isolated were 342 organisms that were not responsible for VAP, making prospective identifications of the true pathogens difficult. Among the 102 episodes for which prior respiratory secretion culture results had been obtained (mean time before VAP onset, 8 +/- 9 d), all the organisms ultimately responsible for pneumonia were previously recovered from only 36 (35%) of these specimens. Based on these data, the contribution of routine microbiologic specimens in guiding initial antimicrobial therapy decisions for patients with suspected VAP appears limited.

Urinary tract infections in Norway: bacterial etiology and susceptibility. A retrospective study of clinical isolates

The objective of the present study was to determine bacterial etiology and susceptibility in urinary tract infections. The study was designed as a retrospective study of urine samples from patients both inside and outside hospitals and nursing homes that were received at our laboratory between 1 January 1997 and 31 October 1999. The Telemark Biomedical Center receives all the medical microbiology specimens from hospitals, nursing homes and general practitioners in the County of Telemark (165,000 inhabitants), Norway. All urines fulfilling the criteria for significant bacteriuria [> or =10,000 colony-forming units/mL urine] were included in the study. Bacterial susceptibility testing was performed using breakpoint methodology. During the study period, we received 52 350 urine samples, of which 28,066 (53.6%) fulfilled the criteria for significant bacteriuria (pure growth of > or =10,000 CFU/mL urine). Escherichia coli was the most predominant bacterium in the urine from both inpatients (56.7%) and outpatients (68.3%). Coagulase-negative staphylococci and enterococci occurred significantly more often (P < 0.001) in urine samples from inpatients (12.5% and 7.9%) than in urine samples from outpatients (7.5% and 4.7%). Escherichia coli from both outpatients and hospitalised patients was highly susceptible (>93%) to cefalothin, mecillinam and nitrofurantoin, and more than 75% of E. coli isolates were also sensitive to ampicillin. Overall, the susceptibility to nitrofurantoin in bacteria from outpatients was 90% and from hospitalised patients was 85%. The corresponding figures for cefalothin were 92% and 90%, and for trimethoprim were 81% and 76%, respectively. Bacteria causing urinary tract infections in Norway are less resistant to antibacterial medication than in other western countries and the reason for this may be the low consumption of antibacterials by the Norwegian population. During the period from 1990 to 1999 the mean total annual consumption of antibacterial drugs in Norway was 15.3 defined daily doses per 1000 inhabitants per year.