Uropathogen distribution and antimicrobial susceptibility in uncomplicated cystitis in Belgium, a high antibiotics prescribing country: 20-year surveillance.

Treatment of cystitis in primary care is usually empirical, guided by the prior probability of causal pathogens and their susceptibility. To re-evaluate empirical treatment guidelines, the actual distribution and susceptibility of uropathogens was examined and compared with two previous surveys in Belgium over the past 20 years. Because of the alarming increase in carriage of extended-spectrum ß-lactamase (ESBL)- and carbapenemase-producing Escherichia coli, this specific resistance was explored. From May 2014 to December 2015, 120 general practitioners collected midstream urine specimens from adult pre- and postmenopausal female patients with suspected cystitis. A dipslide was inoculated and sent for microbiological analysis. Anal swabs were collected for ESBL and carbapenemase detection. Of 265 enrolled patients, 203 (79.3 %) had a positive culture. Escherichia coli (81.6 %) was the most frequently isolated uropathogen, followed by Staphylococcus saprophyticus (8 %), confirming the results of the 1995 and 2005 surveys. The susceptibility of E. coli remained nearly 100 % for nitrofurantoin and fosfomycin, decreased from nearly 100 % in 1995 to 94.2 % for quinolones, from 73.2 to 55.5 % for ampicillin, and from 83.3 to 76.3 % for trimethoprim-sulfamethoxazole (TMP-SMX). In E. coli present in positive urine cultures, ESBLs were found in 2.5 % and carbapenemases were absent. In fecal specimens, ESBL-producing E. coli were found in 7.9 % and carbapenemases were not detected. Over a 20-year period, the distribution of uropathogens in women with cystitis remained unchanged. Susceptibility remained excellent for nitrofurantoin and fosfomycin. For TMP-SMX, ampicillin, and quinolones, there was a decrease.

The resident microflora of voided midstream urine of healthy controls: standard versus expanded urine culture protocols.

The workup and interpretation of urine cultures is not always clear-cut, especially for midstream samples contaminated with commensals. Standard urine culture (SUC) protocols are designed in favor of growth of uropathogens at the expense of commensals. In selected clinical situations, however, it is essential to trace fastidious or new uropathogens by expanding the urine culture conditions (EUC). The aim of our study was to map the microflora in midstream urine specimens from healthy controls by means of EUC, in view of the interpretation of bacterial culture results in symptomatic patients. Midstream urine specimens from 101 healthy controls (86 females and 15 males) were examined using both SUC and EUC. Whilst 73 % of samples examined by SUC showed no growth at 103 colony-forming units (CFU)/mL, 91 % of samples examined by EUC grew bacterial species in large numbers (≥104 CFU/mL). Asymptomatic bacteriuria, as defined by the European guidelines for urinalysis, was detected in six samples with both protocols. EUC revealed 98 different species, mostly Lactobacillus, Staphylococcus, Streptococcus, and Corynebacterium. None of the samples grew Staphylococcus saprophyticus, Corynebacterium urealyticum, or Aerococcus urinae. Samples from females contained higher bacterial loads and showed higher bacterial diversity compared to males. Midstream urine of healthy controls contains large communities of living bacteria that comprise a resident microflora, only revealed by EUC. Hence, the use of EUC instead of SUC in a routine setting would result in more sensitive but less specific results, requiring critical interpretation. In our view, EUC should be reserved for limited indications.

Direct susceptibility testing by disk diffusion on clinical samples: a rapid and accurate tool for antibiotic stewardship.

We compared the accuracy of direct susceptibility testing (DST) with conventional antimicrobial susceptibility testing (AST), both using disk diffusion, on clinical samples. A total of 123 clinical samples (respiratory tract samples, urine, vaginal and abdominal abscess discharges, bile fluid and a haematoma punctate) were selected on various indications; direct inoculation on Mueller-Hinton agar and antibiotic paper disks were applied. In parallel, standard culture, identification and AST on the colonies grown overnight was executed. Both AST and DST were interpreted after identification of the isolates. The results from both AST and DST for 11 antibiotics tested on 97 samples with Gram-negative rods showed 93.4 % total agreement, 1.6 % minor discordances, 4.6 % major discordances and 0.4 % very major discordances. Analysing the discordant results, DST predominantly resulted in more resistant isolates than AST. This was mostly due to the presence of resistant mutants or an additional isolate. The remaining discordances were seen for isolates with inhibition zones close to the clinical breakpoint. For the 26 samples yielding staphylococci, a total agreement of 100 % was observed for the nine antibiotics tested. Overall, the highest percentage of discordant results occurred for the ß-lactam antibiotics amoxicillin-clavulanate (13.4 %) and cefuroxime (12.4 %). When used selectively and interpreted carefully, DST on clinical samples is potentially very useful in the management of critically ill patients, as the time to results is shortened by approximately 24 h. However, we recommend to communicate results with reservations and confirm by conventional AST.

Does facial asymmetry vary between subjects of different age groups? A 3D stereophotogrammetry analysis.

This study was aimed to assess whether facial asymmetry increases with age and to examine potential gender differences using 3D stereophotogrammetry. A prospective cross-sectional study was performed. 3D photographs were acquired from 600 control subjects, 300 male, 300 female, and were stratified into 15 different age groups ranging from 0 to 70+. The 3D photographs were postprocessed and mirrored. The original and mirrored faces were surface-based matched using an iterative closest point algorithm. The primary outcome variable, facial asymmetry, was evaluated by calculating the absolute mean distance between the original and mirrored images. The primary predictor was age. Pearson's correlation was used to assess the correlation between facial asymmetry and age. The average overall facial asymmetry was 0.72 mm (SD 0.72 mm; range 0.25 - 3.04 mm). Mean facial asymmetry increased significantly with age, from 0.45 mm in the age group of 0-4 years to 0.98 mm in the age group of 70+ (p<0.001). Facial asymmetry was positively correlated with age (Pearson's r = 0.55; p<0.001). Male subjects were significantly more asymmetric compared to females, 0.77 mm and 0.67 mm, respectively (p<0.001). This study indicates that facial asymmetry significantly increases with age and is significantly larger in males than in females.

A survey of beta-lactam antibiotics and vancomycin dosing strategies in intensive care units and general wards in Belgian hospitals.

Extended and continuous infusions with beta-lactam antibiotics have been suggested as a means of pharmacokinetic and pharmacodynamic optimisation of antimicrobial therapy. Vancomycin is also frequently administered in continuous infusion, although more for practical reasons. A survey was undertaken to investigate the recommendations by the local antibiotic management teams (AMTs) in Belgian acute hospitals concerning the administration (intermittent, extended or continuous infusion) and therapeutic drug monitoring of four beta-lactam antibiotics (ceftazidime, cefepime, piperacillin-tazobactam, meropenem) and vancomycin for adult patients with a normal kidney function. A structured questionnaire survey comprising three domains was developed and approved by the members of the Belgian Antibiotic Policy Coordination Committee (BAPCOC). The questionnaire was sent by e-mail to the official AMT correspondents of 105 Belgian hospitals, followed by two reminders. The response rate was 32 %, with 94 %, 59 %, 100 %, 100 % and 100 % of the participating Belgian hospitals using ceftazidime, cefepime, piperacillin-tazobactam, meropenem and vancomycin, respectively. Comparing intensive care unit (ICU) with non-ICU wards showed a higher implementation of extended or continuous infusions for ceftazidime (81 % vs. 41 %), cefepime (35 % vs. 10 %), piperacillin-tazobactam (38 % vs. 12 %), meropenem (68 % vs. 35 %) and vancomycin (79 % vs. 44 %) on the ICU wards. A majority of the hospitals recommended a loading dose prior to the first dose. For vancomycin, the loading dose and the trough target concentration were too low based on the current literature. This survey shows that extended and continuous infusions with beta-lactams and vancomycin are widely implemented in Belgian hospitals.

Performance evaluation of a modified chromogenic medium, ChromID MRSA New, for the detection of methicillin-resistant Staphylococcus aureus from clinical specimens.

A novel chromogenic medium for the detection of methicillin-resistant Staphylococcus aureus (MRSA), ChromID MRSA New, was evaluated and compared with the original ChromID MRSA agar, using 355 consecutive screening specimens from nose (120), throat (121) and perineum (114). The specimens were collected with an E-swab and inoculated within 24 hours onto both ChromID MRSA New and on ChromID MRSA. ChromID MRSA New was more sensitive than ChromID MRSA in detecting MRSA after 24 hours of incubation (94.3% versus 81.4%; p < 0.05). With the ChromID MRSA New, processing time is reduced from 48 h to 24 h and confirmation of the resistance to methicillin is redundant.

Systematic surveillance cultures as a tool to predict involvement of multidrug antibiotic resistant bacteria in ventilator-associated pneumonia.

OBJECTIVE: To assess prediction of multidrug resistant (MDR) pathogens in ventilator-associated pneumonia (VAP) by systematic surveillance cultures (SC) and to assess the contribution of SC to initial antibiotic therapy. DESIGN: Prospective cohort study of patients with microbiologically confirmed VAP. Comparison of actual early antibiotic coverage with three hypothetical empirical schemes. SETTING: A 50-bed university hospital ICU. SC consisted of oral, nasal, urinary and rectal samples upon admission, 3-weekly urinary and 1-weekly oral, nasal, and rectal samples in all patients, 3-weekly tracheal aspirates in intubated patients. RESULTS: MDR pathogens were found in 86 of 199 VAP episodes. Sensitivity of SC to predict MDR pathogens was 69% (tracheal SC) and 82% (all SC); specificity was 96% (tracheal) and 91% (all), respectively. Appropriate antibiotic coverage within 24 h and 48 h following MDR VAP was 77% and 89%, respectively. A carbapenem-based empirical scheme would have been equally appropriate (83% vs. 77% at 24 h; 83% vs. 89% at 48 h), but a beta-lactam-fluoroquinolone empirical therapy would have been less (59% vs. 77% at 24 h; 59% vs. 89% at 48 h) as would have been beta-lactam-aminoglycoside therapy (68% vs. 77% at 24 h; 68% vs. 89% at 48 h). Empirical comparators would have resulted in significantly more prescription of broad-spectrum antibiotics within the first 48 h. CONCLUSIONS: With MDR pathogens highly prevalent, systematic SC predicted MDR pathogens causing VAP in 69% to 82% and may have contributed to high rates of early appropriate antibiotic therapy with limited use of broad-spectrum antimicrobials.

Women with symptoms of a urinary tract infection but a negative urine culture: PCR-based quantification of Escherichia coli suggests infection in most cases.

OBJECTIVES: Our objective was to examine whether or not women with symptoms of a urinary tract infection but with a negative culture (20%-30%) do have an infection. METHODS: We performed quantitative PCR (qPCR) for Escherichia coli and Staphylococcus saprophyticus, on top of a standard culture, in urine samples from 220 women with dysuria and/or frequency and/or urgency and from 86 women without symptoms. For symptomatic women, qPCR was also carried out for four sexually transmitted agents. RESULTS: In the symptomatic group, 80.9% (178/220) of the urine cultures were positive for any uropathogen and 95.9% (211/220) were E. coli qPCR-positive. For the control group, cultures for E. coli and E. coli qPCR were positive in, respectively, 10.5% (9/86) and 11.6% (10/86). In the symptomatic group, qPCR yielded 19 positive samples for S. saprophyticus qPCR, one positive sample for Mycoplasma genitalium and one for Trichomonas vaginalis. CONCLUSIONS: These findings suggest that almost all women with typical urinary complaints and a negative culture still have an infection with E. coli.

Head to head comparison of N-terminal pro-B-type natriuretic peptide and B-type natriuretic peptide in patients with/without left ventricular systolic dysfunction.

BACKGROUND: Human pro-B-type natriuretic peptide is cleaved into the active B-type natriuretic peptide (BNP) and the inactive fragment NT-proBNP. It is unclear if, similar to BNP, NT-proBNP can be used as a marker of impaired left ventricular (LV) ejection fraction (EF). This study evaluated the analytical performance of both assays to detect LV systolic dysfunction. METHODS: In 72 patients with various degrees of left ventricular systolic dysfunction (LVSD), blood analysis for BNP and NT-proBNP was performed prior to cardiac catheterization, using a point-of-care analyzer (Biosite) and a fully automated laboratory analyzer (Roche-Elecsys), respectively. The within-run and between-run imprecision for BNP and NT-proBNP was calculated. RESULTS: Both markers were able to detect impaired LV EF with the largest area under the receiver-operating-characteristic curve for NT-proBNP (NT-proBNP: 0.851 (0.747-0.924); BNP: 0.803 (0.692-0.887) 95% confidence interval; P = 0.07). A significant correlation was observed between BNP and NT-proBNP (r = 0.9; P < 0.0001). Estimating the within-run imprecision, the coefficient of variance for BNP was 3.14% (n = 20, mean 316 ng/L) to 3.32% (n = 20, mean 820 ng/L) and for NT-proBNP 0.9% (n = 20, mean 4390.8 ng/L) to 1.4% (n = 20, mean 225 ng/L). The between-run imprecision for NT-proBNP ranged between 2.1% (n = 20, mean 224.6 ng/L) and 2% (n = 20, mean 4391 ng/L). Optimal discriminator values for BNP and NT-proBNP were 139 ng/L and 358 ng/L, respectively. However, adjusting the BNP cut-off value to 54 ng/L improved the negative predictive value and sensitivity of the assay. CONCLUSION: Similar to BNP, NT-proBNP is a promising marker in identifying LVSD. Although both assays are reliable and have good analytical performance, their diagnostic cut-off value is dynamic and population-dependent. The slightly wider detection range and the more stable structure of NT-proBNP compared to the BNP assay suggest that NT-proBNP could play an additional role in the evaluation of patients with LV systolic dysfunction.

Collagenase, procollagenase and bone resorption. Effects of heparin, parathyroid hormone and calcitonin.

1. The addition of heparin to the culture fluid of mouse tibiae or calvaria did not cause any significant resorption of bone collagen or mineral. However, heparin (or analogue sulfated polyanions), enhanced greatly the amount of latent, trypsin-activatable collagenase (i.e. procollagenase) released by the bones in the medium without influencing that of directly active collagenase which was always very low. Heparin appeared to act by increasing the production of the enzyme which is immediately excreted. Procollagenase and collagenase are not stored in bone tissue, even under conditions where it is in active resorption. 2. Parathyroid hormone induced in the explants a resorption of both mineral and collagen that was inhibited by calcitonin. These hormones, however, had no influence on the release of procollagenase or collagenase either in the presence or in the absence of heparin. 3. Once activated, bone collagenase digested the collagen of the bone explants, and more extensively after their demineralization. Thus the latent collagenase that accumulates around non-resorbing bones has to be considered as a precursor, (and not as a residue), of active enzyme. 4. Active collagenase added to incipient cultures of bones disappeared with a half-life of 24 h. The lost enzyme could, however, not be reactivated by trypsin and thus was not transformed into latent procollagenase.

Evaluation of the applicability of amplified rDNA-restriction analysis (ARDRA) to identification of species of the genus Corynebacterium.

The 16S rRNA genes (rDNA) of 50 strains belonging to 26 different coryneform bacterial species and genomospecies and of the type strain of Rhodococcus equi were enzymatically amplified. Amplified rDNA restriction analysis (ARDRA) with the enzymes AluI, CfoI and RsaI was carried out. The combination of the ARDRA patterns obtained after restriction with these three different enzymes enabled the differentiation between the following species: Corynebacterium accolens (number of strains = 2), C. afermentans subsp. afermentans (2), C. afermentans subsp. lipophilum (2), C. amycolatum (3), CDC coryneform group ANF-1-like (1), CDC coryneform group ANF-3-like (1), C. cystitidis (1), C. diphtheriae (4), C. jeikeium (3), C. macginleyi (2), C. minutissimum (1), C. pilosum (1), C. pseudotuberculosis (2), C. renale (2), C. striatum (2), C. urealyticum (3), C. xerosis (1), CDC coryneform groups B-1 (2), B-3 (2), F-1, genomospecies 1 and 2 (6), G, genomospecies 1 (1) and G, genomospecies 2 (2). The following strains or species could not be differentiated from each other: C. pseudodiphtheriticum (2) from C. propinquum (former CDC coryneform group ANF-3) (2), CDC coryneform group F-1, genomospecies 1 (4) from genomospecies 2 (2) and C. jeikeium genomospecies A (1) from genomospecies C (2). ARDRA may represent a possible alternative for identification of coryneforms, since this technique enabled the identification of most coryneforms tested and since DNA extraction (i.e. cell lysis by boiling), amplification, restriction and electrophoresis can be carried out within 8 hours. This might allow quick identification of C. diphtheriae and other possible pathogens of the genus Corynebacterium.

Comparison of arbitrarily primed polymerase chain reaction and cell envelope protein electrophoresis for analysis of Acinetobacter baumannii and A. junii outbreaks.

Two successive Acinetobacter outbreaks in a neonatal intensive care unit were studied with arbitrarily primed polymerase chain reaction (AP-PCR), cell envelope protein electrophoresis (protein fingerprinting) and antibiotic susceptibility testing. AP-PCR fingerprinting and protein fingerprinting yielded identical clustering of the isolates studied. Susceptibility test results were useful for rapid recognition of the outbreaks, but clustering of several isolates was different from the clustering obtained with AP-PCR fingerprinting and protein fingerprinting. Typing results indicated that the two outbreaks, which occurred at a three-month interval, were each caused by a single strain, and that both strains differed from the strains prevailing in the hospital. The strain of one outbreak was identified as A. junii, a species commonly not involved in outbreaks. A. baumannii isolates collected from different departments of this hospital during a period of four years clustered into only five different types. Moreover, strains from different departments of a second hospital belonged to the type prevailing in the first hospital, although there were no apparent connections between the two institutions. This may indicate that only a limited number of strains of the A. calcoaceticus-baumannii complex are involved in nosocomial outbreaks.

Study of the influence of plasmids on the arbitrary primer polymerase chain reaction fingerprint of Escherichia coli strains.

To study the effect of plasmids on the arbitrary primer-polymerase chain reaction fingerprint of bacterial strains, the Escherichia coli strains DH5, Top10, and W3110 were transformed with plasmids of different sizes: respectively, pUC19, pCEP and two clinically important plasmids carrying resistance to several antibiotics. Total DNA, i.e. both chromosomal and plasmid DNA, was prepared from transformed cells by boiling the cell suspensions and by phenol-chloroform extraction; chromosomal DNA was prepared by the same methods from the non-transformed, plasmid-free strains; plasmid DNA of pUC19 was purchased; plasmid DNA of pCEP was purified from the transformed strains by caesium chloride density gradient centrifugation. Arbitrarily primed polymerase chain reaction was carried out for all of these preparations. Amplification carried out independently with three different primers resulted in similar patterns for the chromosomal preparations whether or not plasmid was present. Amplification of plasmid DNA gave different patterns, characterized by fragments larger than those obtained when total or chromosomal DNA were used as the target. These data illustrate that the plasmids studied here do not influence the chromosomal arbitrarily primed PCR fingerprint, although plasmids alone are amplified in the absence of chromosomal DNA. Experiments comparing different relative concentrations of plasmid and chromosomal DNA indicate that under natural conditions the amount of chromosomal DNA per cell is sufficient to inhibit observable amplification of the plasmid(s) present.

Rapid identification of bacteria of the Comamonadaceae with amplified ribosomal DNA-restriction analysis (ARDRA).

Ribosomal rRNA gene fragments (rDNA) encompassing the 16S rDNA, the 16S-23S rDNA spacer region and part of the 23S rDNA of 95 strains belonging to 13 well-described taxa of the eubacterial family Comamonadaceae (beta subclass of the Proteobacteria or rRNA superfamily III) were enzymatically amplified using conserved primers. The fragments of approximately 2400 base pairs were subjected to restriction analysis. Restriction fragment length patterns obtained with HinfI enabled us to distinguish 9 of the 13 taxa studied. Restriction with CfoI was necessary to differentiate Acidovorax delafieldii from A. temperans and Hydrogenophaga flava from H. pseudoflava. The results indicate that amplified rDNA restriction analysis is a simple and reliable tool for the identification of bacterial species.

Modified Granada Agar Medium for the detection of group B Streptococcus carriage in pregnant women.

OBJECTIVES: To improve the detection rate of group B streptococci (GBS) in pregnant women, aiming at the prevention of early-onset septicemia in the newborn. METHODS: The yield from culturing two sites, vaginal and anorectal, on a Modified Granada Medium (MGM) was compared with our standard approach of culturing a vaginal swab on blood agar (BA). RESULTS: Samples were processed from 430 consecutive pregnant women. GBS was isolated from the vagina in 11.6% with BA, and in 13.7% with MGM. In 17.0% of anorectal samples, GBS was identified with MGM. The combination of both sites and media had a yield of 20.0%. MGM identified all but six (2%) of 310 GBS strains after aerobic incubation, with use of a cover slide, and missed only three strains (1%) after anaerobic incubation. CONCLUSIONS: Separate culture of vaginal and anorectal samples using the same MGM agar plate resulted in an increase in detection rate for GBS of 76% as compared to BA alone. The technique is simple and results are available after overnight incubation. MGM was confirmed as a specific medium for the identification of GBS, with a sensitivity of 98-99%.

Evaluation of six commercial assays for the rapid detection of Clostridium difficile toxin and/or antigen in stool specimens.

OBJECTIVE: To evaluate six commercially available assays for the detection of Clostridium difficile toxin and/or antigen in stool samples: one latex agglutination test (Culturette brand CDT, Becton Dickinson), two ELISAs (Culturette brand Toxin CD, Becton Dickinson, and Ridascreen C. difficile Toxin A/B, R-biopharm), two chromatographic assays (Clearview C. difficile A, Oxoid, and ColorPac Toxin A, Becton Dickinson) and one enzyme immunoassay for the simultaneous detection of C. difficile common antigen and toxin A (Triage C. difficile Panel, Biosite). METHODS: Over a period of 3 months, 366 liquid or semi-liquid stool samples were tested using cell-culture cytotoxin assay as standard, ethanol shock stool culture and latex agglutination (Culturette brand CDT). Of these, 78 samples, positive with at least one of these three methods, and 98 randomly selected negative samples were further evaluated using the other five kits. PCR was also performed on positive cultures to confirm the presence of toxin A and B genes. RESULTS: Triage C. difficile Panel had the best sensitivity (95%), followed by Clearview C. difficile and ColorPac Toxin A (both 89%), Culturette brand Toxin CD (73%), Ridascreen C. difficile Toxin A/B (57%) and Culturette brand CDT (23%). For Triage, the sensitivity of C. difficile antigen detection was 93%, and the sensitivity of toxin detection was lower (77%). Most false-positive results were obtained with the Triage C. difficile Panel (25 specimens) and Clearview C. difficile A (20 specimens). Culturette brand CDT had the best specificity (99%); followed by Ridascreen C. difficile Toxin A/B (97%), Culturette brand Toxin CD (95%), ColorPac Toxin A (89%), Clearview C. difficile A (83%) and Triage C. difficile Panel (75%). The positive predictive values ranged from 68% to 94%, and the negative predictive values from 83% to 98%. CONCLUSIONS: The sensitivity is much higher for Triage and the two new chromatographic assays than for the conventional EIAs. These tests also have a high negative predictive value. For Triage, C. difficile antigen-positive, toxin A-negative results can be obtained; the clinical value of these must be established by additional studies. Overall, the new-generation assays are still less sensitive than the cytotoxin assay; however, they provided same-day results, could be used as a screening test and may be useful in laboratories without tissue-culture facilities. Our results do not allow the recommendation of one single assay for the diagnosis of C. difficile-associated diarrhea. It remains the case that laboratory results must be correlated and interpreted with the clinical presentation of the patient.

Tracheal colonization with Sphingomonas paucimobilis in mechanically ventilated neonates due to contaminated ventilator temperature probes.

Sphingomonas paucimobilis was isolated from tracheal secretions of a total of 85 mechanically ventilated babies in a neonatal intensive-care unit (NICU) during a two-year-period. None of the neonates developed pneumonia or sepsis. After each increase in the fluctuating number of S. paucimobilis isolates, extra attention was paid to hand hygiene and to the maintenance of the ventilation equipment. This resulted in a reduction of the frequency of isolation each time. Cultures of all liquids in use and of the ventilation equipment were negative on several occasions. Fifteen months after the start of the outbreak, the NICU was moved to another building, and some older ventilation equipment was abandoned. After a period of six weeks without problems, S. paucimobilis was isolated in association with at least four ventilators. A new investigation showed that the ventilator temperature probes were the source of contamination. Once effective sterilization procedures for the temperature probes were introduced no new cases appeared, until a spare ventilator with an unautoclaved temperature probe was accidentally used and this caused contamination of one child. After correction, no further cases have occurred to date. The clonal relatedness of the outbreak isolates from patients and from ventilator temperature probes was documented by fingerprinting with the arbitrarily primed polymerase chain reaction.

Ten years phage-typing of Belgian clinical methicillin-resistant Staphylococcus aureus isolates (1992-2001).

Gradual changes have been observed in the phage-types of methicillin-resistant Staphylococcus aureus (MRSA) isolates from Belgian hospitals. A total of 6551 isolates, collected in 93 Belgian hospitals over 10 years (1992-2001), was examined. A decreasing incidence of the main early Belgian epidemic phage-types ([A], [B], [H]*, Jo*) was observed. Since 1997 and 2000, a new series of phage-types ([Hv]*, [J]*, [O]*), which were likely related to the previous group [H]*, have been noted. The general trends were confirmed in two particular hospitals. Local epidemic and/or endemic phage-types were also encountered.

Endocarditis from a dental focus. Importance of oral hygiene in valvar heart disease.

Fastidiously growing bacteria more and more are recognised as a source of infectious endocarditis. Over recent years, three new cases of endocarditis caused by Actinobacillus actinomycetemcomitans were diagnosed in our institution. The rise in frequency is possibly secondary to better laboratory skills. Two patients with Actinobacillus (Haemophilus) actinomycetemcomitans endocarditis presented the classical history of preexisting valvar disease together with poor dental hygiene. The third patient had no congenital or rheumatic preexisting lesion to the valves. The distal part of a ventriculo-atrial drainage device had caused microtrauma to the tricuspid valve. The right-sided endocarditis in this patient was complicated by pulmonary septic emboli. Dental origin of the infection was very likely in this patient too. No dental procedure had been performed in the months preceding the endocarditis of our three patients. They presented endocarditis with an oral microorganism in the absence of any dental manipulation. All three had very poor dental hygiene. Better dental care could possibly have prevented this serious complication.

Comparison of some recent methods for the differentiation of elevated serum amylase and the detection of macroamylasaemia.

A pancreatic isoamylase method (Pancreatic Alpha-Amylase EPS, Boehringer) that uses monoclonal antibodies showed almost complete immunoinhibition of salivary (S) amylase activity with only a minor decrease of pancreatic (P) amylase activity. The method displayed good sensitivity and linearity. The correlations of P-amylase activities determined by this technique with a wheat-germ inhibition method and with agarose electrophoresis followed by densitometric scanning were excellent. However, both the wheat-germ and monoclonal inhibition methods failed to detect macroamylasaemia. To recognise macroamylases we used the PEG precipitation method and confirmed the results with agarose electrophoresis. Of 161 serum samples with elevated amylase activities, only four out of five with macroamylasaemia were detected by the PEG precipitation method. No false positives were demonstrated. After PEG precipitation of 28 samples, P-amylase determinations were performed on the supernatants. Again, four out of five with macroamylasaemia were recognised. We consider P-amylase measurement and, when macroamylasaemia is suspected, the combined use of the PEG precipitation method and P-amylase or total amylase determination to be the most practical way to differentiate between elevated serum amylase levels.