Successful containment of two vancomycin-resistant Enterococcus faecium (VRE) outbreaks in a Dutch teaching hospital using environmental sampling and whole-genome sequencing

BACKGROUND

Vancomycin-resistant enterococci (VRE) may cause nosocomial outbreaks. This article describes all VRE carriers that were identified in 2018 at Elisabeth-Tweesteden Hospital, Tilburg, The Netherlands.

AIM

To investigate the genetic relatedness of VRE isolates and the possibility of a common environmental reservoir using environmental sampling and whole-genome sequencing (WGS).

METHODS

Infection control measures consisted of contact isolation, contact surveys, point prevalence screening, environmental sampling, cleaning and disinfection. VRE isolates were sequenced using a MiSeq sequencer (Illumina, San Diego, CA, USA), and assembled using SPAdes v.3.10.1. A minimal spanning tree and a neighbour joining tree based on allelic diversity of core-genome multi-locus sequence typing and accessory genes were created using Ridom SeqSphere+ software (Ridom GmbH, Münster, Germany).

FINDINGS

Over a 1-year period, 19 VRE carriers were identified; of these, 17 were part of two outbreaks. Before environmental cleaning and disinfection, 55 (14%) environmental samples were VRE-positive. Fifty-one isolates (23 patient samples and 28 environmental samples) were available for WGS analysis. Forty-four isolates were assigned to ST117-vanB, five were assigned to ST17-vanB, and two were assigned to ST80-vanB. Isolates from Outbreak 1 (N=22) and Outbreak 2 (N=22) belonged to ST117-vanB; however, WGS showed a different cluster type with 257 allelic differences.

CONCLUSION

WGS of two outbreak strains provided discriminatory information regarding genetic relatedness, and rejected the hypothesis of a common environmental reservoir. A high degree of environmental contamination was associated with higher VRE transmission. Quantification of environmental contamination may reflect the potential for VRE transmission and could therefore support the infection control measures.

Culturing periprosthetic tissue in blood culture bottles results in isolation of additional microorganisms

Despite low sensitivity, culture of periprosthetic tissue (PPT) specimens on agars and in broths has traditionally been used for the detection of causative microorganisms in patients suspected for prosthetic joint infection (PJI). The aim of this study was to evaluate the added diagnostic value of culturing PPT in blood culture bottles (BCB) over the conventional combination of standard agar and broth alone. This prospective cohort study was conducted over a 12-month period and included consecutive patients undergoing revision arthroplasty. Overall, 113 episodes from 90 subjects were studied; 45 subjects (50.0%) met the Infectious Diseases Society of America (IDSA) criteria for PJI, of whom the majority (75.6%) had an acute infection. Sensitivity and specificity of culture were assessed using IDSA criteria for PJI as gold standard. Although the increase in sensitivity from 84.44 (CI 70.54; 93.51) to 93.33% (81.73; 98.60) was not significant, added diagnostic value of culturing PPT in BCBs was demonstrated by the significantly higher number of detected pathogens in culture sets with BCBs compared to culture without BCBs (61 pathogens in conventional set versus 89 when BCBs were included for 57 PJI episodes, P = <0.0001). In 17 (29.8%) episodes, microorganisms were cultured from BCBs only, and in 9 (52.9%) of these episodes, virulent pathogens were found. This study demonstrates that PPT culture in BCBs leads to isolation of additional microorganisms, both virulent and low-virulent, which were not cultured with use of agars and broths alone. Isolation of additional causative microorganisms has serious consequences for the treatment strategy in PJI.

Extended-spectrum β-lactamase (ESBL) polymerase chain reaction assay on rectal swabs and enrichment broth for detection of ESBL carriage

BACKGROUND

Extended-spectrum β-lactamase (ESBL) screening and contact precautions on patients at high risk for ESBL carriage are considered important infection control measures. Since contact precautions are costly and may negatively impact patient care, rapid exclusion of ESBL carriage and therefore earlier discontinuation of contact precautions are desired.

AIM

In the present study, the performance of an ESBL polymerase chain reaction (PCR) targeting blaCTX-M genes was evaluated as a screening assay for ESBL carriage.

METHODS

Two methods were assessed: PCR performed directly on rectal swabs and PCR on enrichment broth after incubation overnight. The reference standard was culture of ESBL-producing Enterobacteriaceae on selective agar after overnight enrichment and confirmation by the combination disc diffusion method. Microarray was used for discrepancy analysis. A secondary analysis was performed to evaluate the added value of including a blaSHV target in the PCR.

FINDINGS

A total of 551 rectal swabs from 385 patients were included, of which 28 (5%) were ESBL positive in culture. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 86%, 98%, 67%, and 99%, respectively, for PCR directly on swabs, and 96%, 98%, 75%, and 100%, respectively, for PCR on enrichment broth. Adding a blaSHV target to the assay resulted in a lower PPV without increasing the sensitivity and NPV.

CONCLUSION

Screening for ESBL by PCR directly on rectal swabs has a high negative predictive value, is up to 48h faster than traditional culture and therefore facilitates earlier discontinuation of contact precautions, thereby improving patient care and saving valuable resources in the hospital.

Shortening the incubation time for the combination disk diffusion extended-spectrum β-lactamase (ESBL) confirmation test: how far can we go?

The combination disk diffusion extended-spectrum β-lactamase (ESBL) confirmation test (CDT) is used for the confirmation of ESBL production in Enterobacteriaceae and usually takes 16-20 h to results. In this study, we searched for the shortest possible incubation time without a reduction in reliability. A total of 125 ESBL screening-positive isolates were subjected to CDT and were molecularly characterised by microarray. Inhibition zones were read every hour over 6-18 h of incubation. Concordance between earlier and 18-h readings was calculated for each hour. Results were validated on 224 isolates during routine clinical practice. For the initial 125 isolates, concordance (Cohen's κ) between the 6-h and 18-h readings was 0.88 [95% confidence interval (CI) 0.78-0.96; P <0.001]. The earliest time point for full concordance with the 18-h reading was 10 h. Validation of the 10-h reading for 224 clinical isolates resulted in a concordance of 0.99 (95% CI 0.98-1.0) between the 10-h and 18-h readings. Overall concordance on all 349 isolates was 0.99 (95% CI 0.97-1.0). Reading after 10 h of incubation has an excellent correlation with results after 18 h of incubation. This can significantly reduce the turnaround time for ESBL detection in laboratories with long opening hours or providing a 24/7 service. Consequently, there is a potential for implementing infection control measures up to 8 h earlier.

Shortening the incubation time for antimicrobial susceptibility testing by disk diffusion for Enterobacteriaceae: how short can it be and are the results accurate?

The standard incubation time for antimicrobial susceptibility testing (AST) by disk diffusion is primarily based on laboratory working hours rather than growth and kill characteristics of bacteria. Faster AST results could result in better patient outcomes and reduced costs by initiating earlier appropriate therapy. The earliest possible reading moment for disk diffusion using established disk zone diameter breakpoints for Enterobacteriaceae was determined with a special focus on the accuracy of the results. A total of 88 Enterobacteriaceae challenge isolates, including isolates with specific resistance mechanisms such as extended-spectrum β-lactamase (ESBL), were subjected to disk diffusion with 15 antibiotics. Hourly images were automatically produced by an incubator/camera combination from 1 h to 20 h. Disk zones were plotted over time for all combinations. Essential and categorical agreement rates using the final reading after 20 h of incubation as a reference were calculated for every hour. In total, 1320 antibiotic-micro-organism combinations were tested. Clear growth with readable inhibition zones was visible after 6 h of incubation for the majority (95.8%) of plates and after 7 h for all incubated plates. However, zone sizes changed significantly after those time points for a number of strains. After 10 h of incubation, minor, major and very major error rates were 1.6% (n = 21), 0.2% (n = 1) and 0.7% (n = 4), respectively. The results of this study clearly indicate that early reading of inhibition zones to 10 h after incubation is feasible and accurate and thus may save significantly on turnaround time.

Rapid clearance of Giardia lamblia DNA from the gut after successful treatment

To assess the time it takes for a real-time PCR to become negative after treatment of a Giardia lamblia infection, we evaluated two consecutive follow-up samples from 75 infected patients. Approximately 1 week after treatment all samples tested negative, indicating rapid clearance of parasitic DNA after successful treatment.

Diagnostic value of respiratory virus detection in symptomatic children using real-time PCR

Background

Acute respiratory tract infections are an important public health problem. Sensitive and rapid diagnostic techniques have been developed and are used in daily clinical practice. Here we evaluate the clinical relevance of detecting 20 common respiratory pathogens by molecular methods in a general pediatric clinic.

Methods

Nasopharynx samples of children < 18 years of age with respiratory symptoms referred to a general pediatric clinic were tested for the presence of 19 viruses and Mycoplasma pneumoniae, using real-time polymerase chain reaction.

Results

Of 177 patients included in this retrospective study, 73% were positive for at least one virus. Respiratory syncytial virus (36.6%) and human rhinovirus (24%) were most frequently detected. Patients in whom a respiratory virus or Mycoplasma pneumoniae was detected, were younger (6 versus 24 months; p < 0.001) and more often hospitalized (116 versus 34; p = 0.001) than patients in whom no respiratory pathogen was detected. Also they were more likely to present with feeding problems, dyspnea, rhinorrhea and wheezing (all p < 0.05) than patients without a respiratory pathogen.

In the majority of cases, clinicians did not change their antibiotic management after detecting a viral respiratory pathogen. No difference in mean Ct value was found between patients with one respiratory pathogen and those with >1 respiratory pathogen (30.5 versus 31.2; p = 0.573).

Conclusion

Routine testing of common respiratory pathogens could lead to a better understanding of their role in disease in children with respiratory symptoms.

Recent emergence of Staphylococcus aureus clonal complex 398 in human blood cultures

Background

Recently, a clone of MRSA with clonal complex 398 (CC398) has emerged that is related to an extensive reservoir in animals, especially pigs and veal calves. It has been reported previously that methicillin-susceptible variants of CC398 circulate among humans at low frequency, and these have been isolated in a few cases of bloodstream infections (BSI). The purpose of this study was to determine the prevalence of S. aureus CC398 in blood cultures taken from patients in a geographic area with a high density of pigs.

Methodology/Principal Findings

In total, 612 consecutive episodes of S. aureus BSI diagnosed before and during the emergence of CC398 were included. Three strains (2 MSSA and 1 MRSA) that were isolated from bacteremic patients between 2010–2011 were positive in a CC398 specific PCR. There was a marked increase in prevalence of S. aureus CC398 BSI isolated between 2010–2011 compared to the combined collections that were isolated between 1996–1998 and 2002–2005 (3/157, 1.9% vs. 0/455, 0.0%; p = 0.017).

Conclusions/Significance

In conclusion, in an area with a relative high density of pigs, S. aureus CC398 was found as a cause of BSI in humans only recently. This indicates that S. aureus CC398 is able to cause invasive infections in humans and that the prevalence is rising. Careful monitoring of the evolution and epidemiology of S. aureus CC398 in animals and humans is therefore important.

Prevalence of livestock-associated MRSA in communities with high pig-densities in The Netherlands

Background

Recently, livestock-associated methicillin-resistant Staphylococcus aureus CC398 has been discovered in animals, livestock farmers and retail meat. This cross-sectional study aimed to determine the spread to persons not in direct contact with livestock in areas with a high density of pig farms.

Methodology/Principal Findings

With a random mailing in 3 selected municipalities in the Netherlands, adult persons were asked to fill in a questionnaire and to take a nose swab. In total, complete information was obtained on 583 persons. Of the 534 persons without livestock-contact, one was positive for MRSA (0.2%; 95% confidence interval, <0.01–1.2). Of the 49 persons who did indicate to be working at or living on a livestock farm, 13 were positive for MRSA (26.5%; 95% confidence interval, 16.1–40.4). All spa-types belonged to CC398.

Conclusions/Significance

Livestock-associated MRSA has a high prevalence in people with direct contact with animals. At this moment it has not spread from the farms into the community.

[Does ultraclean air in the operating room provide greater safety?]

The Dutch quality control plan for climatisation of the operating room (OR), which was published in 2005, describes the management and maintenance of the air conditioning system. This management plan proposes a standard for air quality in class 1 ORs. This has been adopted by the Dutch Orthopaedic Society, but not by other surgical societies. The British study which underlies the proposed norm for air quality in class 1 ORs, a study on the infection preventive effect of ultraclean air, dates from 1982 and is inadequately controlled for prophylactic use of antibiotics. Antibiotic prophylaxis in itself already reduces the number of surgical site infections.-More recent studies fail to show an infection preventive effect of ultraclean air in the OR. The Dutch Working Party for Infection Prevention (WIP) ought to take the initiative, together with the medical Scientific Societies and the Society of Infection Prevention and Control in the health care setting (VHIG), to establish enforceable norms for microbiological air quality and to set criteria as to which types of operations are allowed to be performed in which class of OR.

[Optimalization of antibiotic policy in the Netherlands. VII. SWAB-guidelines for antimicrobial therapy in adults patients with infectious endocarditis]

The Working Party on Antibiotic Policy (Dutch acronym: SWAB) has developed guidelines for in-hospital antimicrobial therapy of adult patients with infective endocarditis. The choice and the duration of antimicrobial therapy are determined by the infecting micro-organism, the sensitivity of this micro-organism to antimicrobial therapy, the location of the endocarditis (left- or right-sided) and the presence of intracardial prosthetic material. While waiting for the culture results, the antibiotic treatment of an infected native valve is benzylpenicillin (in cases which begin subacutely or have a long history) or flucloxacillin (cases which begin acutely, are fulminant or in i.v. drug users), and gentamicin. If a prosthetic valve is infected then treatment of choice is vancomycin and gentamicin. Further antibiotic treatment depends on the causative micro-organism. Streptococci, enterococci and staphylococci are the most frequently occurring of these.

[Diagnostic image (157). A man with fever and a 'tache noire' after a holiday in South Africa. Rickettsiosis, probably African tick-bite fever]

A 54-year-old man presented with fever and an eschar, probably caused by African tick-bite fever, contracted during a holiday in South Africa. He recovered rapidly after treatment with doxycyclin.

The risk of Strongyloides stercoralis transmission from patients with disseminated strongyloidiasis to the medical staff

To assess the risk of Strongyloides stercoralis transmission from two patients with disseminated strongyloidiasis to medical staff who had been in close contact with the patients, blood and stool specimens were obtained from medical staff two to three months after close contact with the patients. Antibodies to S. stercoralis were determined in blood. Stool specimens were tested for parasites with three different procedures.Forty-one medical staff were included. Culture and stool examination were negative in all subjects. Serology was negative in all subjects but one who had a borderline titer without signs or symptoms of strongyloidiasis. No evidence of transmission of S. stercoralis from patients with disseminated strongyloidiasis to medical staff was found.

Infectious complications and antibiotic use in renal transplant recipients during a 1-year follow-up

OBJECTIVE

To evaluate infectious complications and antibiotic use in 192 renal transplant recipients.

METHODS

Infectious complications and antibiotic use were monitored in all patients receiving renal transplantation at our center from 1992 to 1997. Risk factors for infectious complications were evaluated. Transplants and patient survival were monitored. The follow-up period was 1 year.

RESULTS

One-hundred and ninety-two patients received renal transplants during the study period. The mean duration of urethral catheterisation after transplantation was 10.5 days (SD = 5). Seventy-one per cent (n = 137) of patients had at least one infectious episode. In all, 284 infectious episodes were monitored. The most frequent infections were: urinary tract infections 61%, respiratory tract infections 8%, intra-abdominal infections 7%, and cytomegalovirus infection 8%. Escherichia coli and Enterococcus faecalis were the most frequently isolated microorganisms. Seventy-four per cent (n = 142) of patients received 314 antimicrobial courses (284 for therapy, and 30 for prophylaxis). Female gender and duration of urethral catheterisation were risk factors for urinary tract infection. Cytomegalovirus reactivation was associated with acute graft rejection and additional immunosuppressive therapy. Overall mortality was 4%. Infection-related mortality was 2.6%. Mortality was associated with Enterobacteriaceae in three patients, with Pseudomonas aeroginosa in one patient and with Enterococcus faecalis in one patient.

CONCLUSIONS

The incidence of infectious complications remains high in renal transplant recipients. Most cases of mortality were associated with infections. Early removal of the urethral catheter to reduce the risk of urinary tract infections is recommended.

BCG immunotherapy: be cautious of granulomas. Disseminated BCG infection and mycotic aneurysm as late complications of intravesical BCG instillations

We describe a 65-year-old man with a granulomatous hepatitis and a progressive mycotic aneurysm of the abdominal aorta. One year before he received intravesical bacillus Calmette--Guérin (BCG) for carcinoma of the bladder without any complaints. Only post-mortem investigations could confirm that he suffered from a systemic BCG infection. Literature is reviewed for this rare complication.

Prevalence and determinants of fecal colonization with vancomycin-resistant Enterococcus in hospitalized patients in The Netherlands

OBJECTIVE

To determine the prevalence and determinants of fecal carriage of vancomycin-resistant enterococci (VRE) in intensive care unit (ICU), hematology-oncology, and hemodialysis patients in The Netherlands.

DESIGN

Descriptive, multicenter study, with yearly 1-week point-prevalence assessments between 1995 and 1998.

POPULATION

All patients hospitalized on the testing days in ICUs and hematology-oncology wards in nine hospitals in The Netherlands were included.

METHODS

Rectal swabs obtained from 1,112 patients were screened for enterococci in a selective broth and subcultured on selective media with and without 6 mg/L vancomycin. Resistance genotypes were determined by polymerase chain reaction. Further characterization of VRE strains was done by pulsed-field gel electrophoresis (PFGE). We studied possible determinants of VRE colonization with a logistic regression analysis model. Determinants analyzed included gender, age, and log-transformed length of prior hospital stay.

RESULTS

The results showed that 614 (55%) of 1,112 patients were colonized with vancomycin-sensitive enterococci, and 15 (1.4%) of 1,112 carried VRE. No increase in VRE colonization was observed from 1995 to 1998. Eleven strains were identified as Enterococcus faecium and four as Enterococcus faecalis. All E faecium and one E faecalis carried the vanA gene; the other E faecalis strains harbored the vanB gene. PFGE revealed that three vanB VRE isolated from patients hospitalized in one single ICU were related, suggesting nosocomial transmission. Though higher age seemed associated with VRE colonization, exclusion of patients with the nosocomial strain from the regression analysis decreased this relation to nonsignificant. Duration of hospital stay was not associated with VRE colonization.

CONCLUSION

VRE colonization in Dutch hospitals is an infrequent phenomenon. Although nosocomial spread occurs, most observed cases were unrelated, which suggests the possibility of VRE acquisition from outside the hospital. Prolonged hospital stay, age, and gender proved unrelated to VRE colonization.

Increasing resistance to fluoroquinolones in escherichia coli from urinary tract infections in the netherlands

In continuous surveillance of routine samples from five Dutch laboratories, we studied resistance to the antibiotics most commonly prescribed for urinary tract infections (UTI) in The Netherlands, namely norfloxacin, amoxycillin, trimethoprim and nitrofurantoin, from 1989 to 1998 in >90000 Escherichia coli isolates. Resistance to norfloxacin increased from 1.3% in 1989 to 5.8% in 1998. Multiresistance, defined as resistance to norfloxacin and at least two of the other three antibiotics, increased from 0.5% in 1989 to 4. 0% in 1998. Multivariate analysis of the norfloxacin resistance demonstrated that this yearly increase (the odds ratio was 1.0 in 1989, 1.6 in 1992, 2.9 in 1995 and 6.1 in 1998) was independent of other determinants of resistance to norfloxacin, such as age, gender and origin of the isolate. Analysis of strata, classified by year, age and gender, demonstrated an association between prescription of fluoroquinolones (defined daily doses per case of UTI) and resistance to norfloxacin in E. coli (P < 0.001). There was no significant association with the prescription of nitrofuran derivatives (nitrofurantoin) and trimethoprim with or without sulphamethoxazole. The yearly increase of resistance to fluoroquinolones in E. coli from UTI may stem from increased prescription of fluoroquinolones for UTI. Resistance of E. coli to these agents is likely to increase further as fluoroquinolone use increases in future.

Evaluation of four enzyme immunoassays for the detection of Giardia lamblia antigen in stool specimens

Four enzyme immunoassays for the detection of Giardia lamblia antigen in stool specimens were evaluated: the ProSpecT Giardia Microplate Assay (Alexon, USA), the Giardia CELISA (Cellabs, Australia), the DSL-Giardia-ELISA (DSL. Germany), and the Melotest Giardiasis Ag (Melotec, Spain). Microscopic examination and enzyme immunoassays were performed on 168 stool specimens collected from 168 patients suspected to have giardiasis. All assays were easy to perform. The ProSpecT Giardia assay had the highest sensitivity of the assays evaluated (91%), and its interpretation was the easiest. The sensitivity of the three other assays ranged from 63 to 81%. The ProSpecT Giardia assay can be useful to detect Giardia lamblia and may replace microscopic examination in areas of high endemicity.

Occurrence of extended-spectrum betalactamases (ESBL) in Dutch hospitals

The prevalence of ESBL was determined among isolates of Escherichia coli (n = 571) and Klebsiella spp. (n = 196) collected during a 1-week study period in 8 university and 3 large regional laboratories all over the Netherlands. 18 isolates were positive for at least one of the screening tests used, i.e., VITEK-ESBL, E-test ESBL and MIC ratio of ceftazidime/ceftazidime-clavulanic acid, cefotaxime/cefotaxime-clavulanic acid. In 5 of these 18 putative ESBLs no betalactamase production was detectable. A TEM type was found in three E. coli and two Klebsiella spp. An SHV type was present in five Klebsiella spp. In one E. coli and one Klebsiella pneumoniae both enzymes were present. In one Klebsiella oxytoca neither of the two enzymes was present. Using PCR for both ESBL TEM and ESBL SHV, an SHV ESBL was found in one E. coli and four Klebsiella isolates. The mutations at position 238 and 240 were already described. In one E. coli isolate a TEM ESBL was found with three mutations, at position 21, 164 and 265. These mutations were already described in other ESBLs but not in this combination suggesting a new TEM ESBL. The overall prevalence of ESBL producing E. coli and Klebsiella spp. was less than 1% (6 out of 767).

Three cases of serious infection caused by Aerococcus urinae

Three cases of serious infection caused by Aerococcus urinae are presented: a patient with endocarditis and two patients with soft-tissue infection (phlegmon and balanitis respectively). The literature on Aerococcus urinae infections is reviewed and the antibiotic therapy discussed. Aerococcus urinae is a pathogen isolated primarily from urine specimens of elderly patients with local or systemic predisposing conditions. Most infections are mild, but serious infections such as endocarditis and septicemia/urosepsis have been described. Penicillin or ampicillin in combination with an aminoglycoside and close monitoring of the patient's clinical status and laboratory results would seem to be the best strategy for management of cases of serious infection.

Aortic graft infection by Lactobacillus casei: a case report

A 65-year-old man with an abdominal aortic endoprosthesis presented with fever without other symptoms. Investigations revealed Lactobacillus casei bacteraemia. The Lactobacillus graft infection was at first successfully treated by antibiotic therapy. However, during follow-up a relapse occurred, and after surgical replacement of the graft the patient was cured. At surgery an aortoenteric fistula was found as source of the infection.

Resistance of staphylococci in The Netherlands: surveillance by an electronic network during 1989-1995

An electronic surveillance network for monitoring antibiotic resistance in The Netherlands has been in operation since 1989. Seven public health laboratories participate and the system covers about 25% of all bacteriological determinations in The Netherlands. This paper reports the results of staphylococci isolated in the period 1989-1995. About 0.3% of the Staphylococcus aureus isolates in the study period were resistant to methicillin. This low percentage may be due to the restrictive use of antibiotics and to strict isolation measures aimed at eradicating methicillin-resistant S. aureus. Low frequencies of resistance among methicillin-resistant S. aureus were found for vancomycin (0%), chloramphenicol (11%), cotrimoxazole (11%), mupirocin (3% low-level resistance) and fusidic acid (7%). Twenty-one percent of the coagulase-negative staphylococci were resistant to methicillin. Low frequencies of resistance among these methicillin-resistant coagulase-negative staphylococci were those to vancomycin (0.4%), nitrofurantoin (2%), doxycycline (20%) and amikacin (20%). Coagulase-negative staphylococci from cerebrospinal fluid, blood and skin were less often resistant to quinolones than isolates from respiratory tract, faeces and urine. A significant increase in resistance of coagulase-negative staphylococci to methicillin, erythromycin, gentamicin and ciprofloxacin was observed in the investigated period but the resistance to doxycycline and co-trimoxazole decreased in the last few years. To confirm the determination of methicillin resistance and coagulase production, a PCR method was developed which detects both the mecA and the coagulase gene. The results of the PCR method correlated well with the methicillin MIC as determined by an agar-dilution method.

Fecal carriage of vancomycin-resistant enterococci in hospitalized patients and those living in the community in The Netherlands

In order to determine the prevalence of vancomycin-resistant enterococci (VRE) in The Netherlands, 624 hospitalized patients from intensive care units or hemato-oncology wards in nine hospitals and 200 patients living in the community were screened for VRE colonization. Enterococci were found in 49% of the hospitalized patients and in 80% of the patients living in the community. Of these strains, 43 and 32%, respectively, were Enterococcus faecium. VRE were isolated from 12 of 624 (2%) and 4 of 200 (2%) hospitalized patients and patients living in the community, respectively. PCR analysis of these 16 strains and 11 additional clinical VRE isolates from one of the participating hospitals revealed 24 vanA gene-containing, 1 vanB gene-containing, and 2 vanC1 gene-containing strains. All strains were cross-resistant to avoparcin but were sensitive to the novel glycopeptide antibiotic LY333328. Genotyping of the strains by arbitrarily primed PCR and pulsed-field gel electrophoresis revealed a high degree of genetic heterogeneity. This underscores a lack of hospital-driven endemicity of VRE clones. It is suggested that the VRE in hospitalized patients have originated from unknown sources in the community.

Urinary tract infections with Aerococcus urinae in the south of The Netherlands

Aerococcus urinae is an uncommon urinary tract pathogen that causes infections predominantly in elderly persons with local or general predisposing conditions. During a one-year study, the clinical features of Aerococcus urinae urinary tract infections (> or = 10(5) cfu/ml) were investigated in two large medical microbiology laboratories in the Netherlands. The incidence of Aerococcus urinae urinary tract infections ranged between 0.31 and 0.44% for the two laboratories. The median age (range 35-95 years) of patients with this infection was 82.5 years for women and 77.5 for men. Men had significantly (p < 0.01) more local predisposing conditions than did women. Underlying systemic diseases such as diabetes mellitus, malignancy, and dementia were found in 67.5% of patients. Most patients (97.5%) had the classic signs of a urinary tract infection, but none of them developed serious symptoms. All isolates tested were susceptible to penicillin, amoxicillin, and nitrofurantoin, 78.3% were susceptible to norfloxacin, and all were resistant to sulfonamides. The majority of patients were treated with amoxicillin, amoxicillin with clavulanic acid, or norfloxacin.

Use of random amplification of polymorphic DNA in a case of Pasteurella multocida meningitis that occurred following a cat scratch on the head

We cultured Pasteurella multocida from the cerebrospinal fluid (CSF) of a 4-month-old infant who presented with meningitis. The patient had been scratched on the head by a cat. Culture of the cat's claws also yielded P. multocida. The isolates had identical biochemical patterns. Analysis of both strains by random amplification of polymorphic DNA and comparison of these strains with P. multocida strains isolated from other cats showed that the two strains were identical and completely different from the unrelated isolates. Our patient's meningitis most likely resulted from direct inoculation of P. multocida into the CSF.

Chronic meningococcaemia: a case report

Chronic meningococcaemia (CM), caused by the bacterium Neisseria meningitidis is reported in a 27-year-old Indonesian man. The main symptoms were intermittent fever, skin rash and arthralgia. The pathogenesis, symptoms, differential diagnoses and treatment of CM are discussed.

Comparison of fluorescent BACTEC 9000 MB system, Septi-Chek AFB system, and Lowenstein-Jensen medium for detection of mycobacteria

The newly developed fluorescent BACTEC 9000 MB system for automated culture of mycobacteria was compared with the Septi-Chek AFB system and Lowenstein-Jensen medium (LJ). A total of 2,005 clinical specimens were included in the study. Mycobacteria were isolated from 202 (10.1%) specimens, including 155 Mycobacterium tuberculosis complex isolates and 47 Mycobacteria other than M. tuberculosis isolates. Of 131 isolates detected by the BACTEC system, the Septi-Chek AFB system, or both, 120 (91.6%) were detected by the BACTEC system and 105 (80.2%) were detected by the Septi-Chek AFB system (P < 0.02). The recovery rate in the BACTEC system compared with that in the Septi-Chek AFB system was significantly higher for M. tuberculosis complex isolates (P < 0.005) and for isolates from acid-fast smear-negative specimens (P < 0.01). Of 148 isolates detected by the BACTEC system, LJ, or both, 142 (95.9%) were detected by the BACTEC system and 118 (79.9%) were detected by LJ (P < 0.001). The recovery rate in the BACTEC system compared with that on LJ was significantly higher for M. tuberculosis complex isolates (P < 0.001). The BACTEC system detected more mycobacteria from both smear-positive and smear-negative specimens than LJ. The mean times to detection of mycobacteria were 17.6 days for the BACTEC system, 26.0 days for the Septi-Chek AFB system, and 29.4 days for LJ. The BACTEC fluorescent 9000 MB system is a rapid, sensitive, and efficient method for the isolation of mycobacteria.

[Rhabdomyolysis and kidney insufficiency in van Weil syndrome]

In two men, aged 20 and 23 years, who suffered from fever, jaundice, severe muscle pain and decreased renal function, Weil's syndrome was diagnosed, accompanied by severe rhabdomyolysis. Haemodialysis was needed temporarily in one patient. Leptospirosis is a zoonosis caused by spirochaetes. It is a rare disorder in the Netherlands. In 5-10% of the patients so-called icteric leptospirosis is seen: Weil's syndrome. The diagnosis of Weil's syndrome is supported by the presence of high fever, intense muscle aching and jaundice. Renal involvement is frequent and haemodialysis is sometimes required. The pathogenesis of the tubular necrosis is unclear. Adequate therapy can prevent irreversible renal damage.

Native-valve endocarditis due to CDC coryneform group ANF-3: report of a case and review of corynebacterial endocarditis

Endocarditis due to a bacterium of CDC coryneform group ANF-3 developed in the native aortic valve of a patient without predisposing factors other than valvular calcification. A review of the literature indicates that corynebacteria are an increasingly important cause of endocarditis. Problems in identification and treatment remain. Techniques for the culture and quick identification of these organisms and effective regimens for treatment of the infections they cause are needed.

[Mycetoma of the foot; a disease from the tropics]

Two patients, a Surinamese man aged 50 and a Surinamese woman aged 56 exhibited a mycetoma of the foot, 30 and 28 years, respectively, after a local injury. Pathological examination revealed an aspecific chronic granulomatous inflammation. As causative agents a Fusarium species and a Cladosporium normodendrum, respectively, were cultured. The treatment consisted of curettage of fistulous ducts and administration of itraconazole.

[A patient with chronic mucormycosis]

Rhinocerebral mucormycosis was diagnosed in a 75-year-old woman with a history of type II diabetes mellitus. This rare opportunistic infection is caused by fungi belonging to the order of Mucorales. The patient had a severe osteomyelitis of the base of the skull, resulting in complaints of headache and diplopia. She was treated with intravenous colloidal amphotericin B, surgical excision, and later with liposomal amphotericin B. She died of respiratory failure. Mucormycosis is usually a rapidly fulminant infection. This patient showed a remarkably chronic course.

[An unusual hospital infection: Aeromonas hydrophila infection due to the use of leeches]

A patient is described with an infection with Aeromonas hydrophila after the use of medical leeches to improve the circulation of a congested region of surgery. The use of medical leeches and the treatment of a leech-related infection are discussed.

Procoagulant activity of endocardial vegetations and blood monocytes in rabbits with Streptococcus sanguis endocarditis

To investigate activation of the coagulation system in bacterial endocarditis, we determined the procoagulant activity of blood monocytes isolated from rabbits with Streptococcus sanguis-infected or sterile catheter-induced endocardial vegetations. This activity was determined directly after isolation from the peripheral blood and after stimulation in vitro by either endotoxin or by phagocytosis of S. sanguis. The procoagulant activity of the vegetations of these rabbits was also determined. The procoagulant activity of blood monocytes of rabbits with S. sanguis endocarditis was found to be similar to the activity of monocytes of rabbits with sterile vegetations, both at the time of isolation and after stimulation in vitro by exposure to endotoxin or phagocytosis of bacteria. The procoagulant activity of infected vegetations was significantly higher than that of sterile vegetations. We conclude that in bacterial endocarditis the coagulation system is activated locally at the site of the vegetation. Triggering probably occurs by thromboplastin generated by monocytes activated by phagocytosis of bacteria on the vegetational surface.

Effects of tissue-type plasminogen activator (t-PA) on Streptococcus sanguis-infected endocardial vegetations in vitro

The effects were studied of in-vitro exposure to tissue-type plasminogen activator (t-PA) on endocardial vegetations isolated from rabbits with Streptococcus sanguis endocarditis as well as on Str. sanguis-infected plasma clots. For both vegetations and clots t-PA induced lysis of the infected fibrin matrix, demonstrated by a release of streptococci into the incubation medium and by an increase in the concentration of fibrin degradation products. The clots decreased in weight, whereas only partial lysis of the vegetations was obtained. Addition of plasminogen to the incubation medium did not enhance the effect of t-PA on vegetations. Fibrinolysis by t-PA did not interfere with the antimicrobial action of benzylpenicillin on the bacteria in a fibrin matrix. It is concluded that t-PA can degrade the fibrin matrices of infected endocardial vegetations and plasma clots. Reduction of vegetation size by t-PA may prove to be useful in the treatment of bacterial endocarditis.

Effects of tissue-type plasminogen activator on Staphylococcus epidermidis--infected plasma clots as a model of infected endocardial vegetations

The ability of tissue-type plasminogen activator (t-PA) to enhance the effect of antibiotics in the treatment of bacterial endocarditis was studied using plasma clots infected with Staphylococcus epidermidis as a model of infected endocardial vegetations. A concentration-dependent lysis of the infected plasma clots was induced by t-PA, as shown by the decrease in the weight of the clots, a decrease in the amount of incorporated 125I fibrin, as well as the release of staphylococci from the clots into the incubation fluid. The addition of cloxacillin to the incubation medium in various concentrations led to a concentration-dependent decrease of the number of S. epidermidis in the clots. The presence of t-PA did not enhance the antibacterial effect of cloxacillin. It is concluded that the lysis induced by t-PA might enhance the effect of treatment of endocarditis by reducing the size of endocardial vegetations but not by enhancement of the effect of antibiotics on the bacteria embedded in the vegetations.