Distribution of extended-spectrum beta-lactamase genes using a commercial DNA micro-array system.

Extended-spectrum beta-lactamase (ESBL) genes are distributed worldwide and their epidemiology is complex. Using the Check-ESBL assay, the distribution of class A ESBL genes in clinical isolates of aerobic Gram-negative bacilli from three laboratories in the East of The Netherlands was determined. Four patient categories were distinguished: (i) patients admitted to an intensive care unit (ICU); (ii) non-ICU inpatients; (iii) outpatients admitted less than a year before collection of the isolate, (<1); (iv) outpatients admitted more than one-year prior to isolate collection or who had never been hospitalized (>1). From February 2009 until March 2010, out of 491 putative ESBL-positive isolates detected by the Vitek2 or Phoenix automated sensitivity testing systems, ESBL genes were detected in 247 (50.3%) by the Check-ESBL assay. Of these, 116 were from hospitalized patients (35 ICU, 81 non-ICU) and 131 were from outpatients (43 <1, 88 >1). In all, 274 ESBL genes were identified in these 247 isolates: 153 CTX-M-1 group (predominantly in E. coli and K. pneumoniae, 70.4% and 51.6% respectively), 67 CTX-M-9 group (predominantly in E. cloacae, 57.9%), 32 SHV, 14 TEM and 8 CTX-M-2 group. ESBL-producing E. cloacae were significantly more common in hospitalized patients than in outpatients, 20.7% and 3.8% respectively (P=0.001). CTX-M-9 group ESBLs were significantly more prevalent in ICU patients (P=0.003), whereas SHV ESBLs were more common in hospitalized patients than in outpatients (P<0.001). There was no significant difference in distribution of ESBL genes between the two outpatient groups.

Anti-HBs levels after hepatitis B immunisation depend on test reagents: routinely determined 10 and 100 IU/l seroprotection levels unreliable.

In a large series of post-vaccination samples we compared the result of three commercially available anti-HBs assays (AxSYM, Architect and Access) on the quantitation of anti-HBs after immunisation with Engerix-B (HBsAg/ad) and GenHevacB (HBsAg/ay) vaccine. Two of the assays (AxSYM, Architect: Abbott Laboratories) gave related but not identical results with HBsAg from different sources. The result of the third assay (Access, Beckman Coulter) was related to that of AxSYM and Architect only for GenHevacB anti-HBs but differed for Engerix-B anti-HBs (P<0.001). This vaccine dependent discrepancy was also observed with the Vidas anti-HBs assay (BioMerieux). An external WHO reference panel could harmonise geometric mean anti-HBs levels from the four assays for GenHevacB but not for Engerix-B vaccination sera. We conclude that the individually determined anti-HBs level (IU/l) strongly depend on the test reagents and the vaccine under study.

One-day detection of PCR amplified Chlamydia trachomatis DNA in clinical samples: ELISA versus Southern blot hybridisation.

AIMS: To compare ELISA and Southern blot hybridisation for the detection of PCR amplified Chlamydia trachomatis DNA extracted from clinical samples; to assess the value of the ELISA method in a clinical setting. METHODS: DNA was extracted from urogenital samples of 508 patients, purified and amplified using C trachomatis specific primers, one of which was endlabelled with biotin. Amplification products were detected by Streptavidin biotin based ELISA and non-radioactive Southern blotting. RESULTS: Of the 508 samples, 29 were positive and 479 negative by both methods. No discrepant results were observed. CONCLUSION: Streptavidin biotin based ELISA and Southern blotting were equally sensitive for detecting PCR amplified C trachomatis DNA. Using ELISA, test results could be generated within a single day.

Aseptic meningitis caused by the lymphocytic choriomeningitis virus.

We present a 38-year old man suffering from a biphasic illness with fever and malaise, who developed a mild aseptic meningitis during the second phase. Lymphocytic choriomeningitis virus was found to be the causative agent.

Qualitative and quantitative kinetics of submucosally administered antibody fragments in patients with rectal carcinoma: the detection of lymph node metastasis in relation to local tracer diffusion.

Immunoscintigraphy after submucosal administration of a mixture of 131I-anti-CEA and 131I-anti-CA-19-9 around the tumor in patients with rectal carcinoma may improve pre-operative staging and may contribute to the selection of patients eligible for local treatment. However, visual discrimination of local lymph node metastasis appears unreliable, partly because of scatter from the injection site and substantial diffusion of the radiotracer into the interstitium. Analysis of the diffusion profile, however, may improve the sensitivity and accuracy of this immunoscintigraphic approach.

Diagnosis of herpes simplex virus encephalitis by detection of virus-specific immunoglobulins A and G in serum and cerebrospinal fluid by using an antibody-capture enzyme-linked immunosorbent assay.

An enzyme-linked immunosorbent assay was evaluated for detection of intrathecal synthesis of immunoglobulin G (IgG) and IgA antibodies to herpes simplex virus (HSV) in patients with HSV encephalitis (HSVE). Since the antibody-capture principle was used and the assay was carried out at the saturation level of the anti-IgG- or anti-IgA-coated solid phase, correction for blood-brain barrier leakage was not needed. A total of 34 pairs of serum and cerebrospinal fluid specimens obtained from 20 patients with HSVE were examined. Intrathecal synthesis of HSV IgG and IgA was detected from day 7 after the onset of illness in patients with HSVE. Specimens from all 19 patients from whom paired serum and cerebrospinal fluid specimens were obtained at more than 10 days after the onset of illness were positive. Intrathecal synthesis of HSV IgG and IgA was not detected in patients with HSVE before day 7 of illness or in any of the 16 control patients with other causes of (meningo)encephalitis. Use of the antibody-capture enzyme-linked immunosorbent assay for HSV IgG and IgA allows the rapid diagnosis of HSVE during the second week of illness.