The use of typing methods and infection prevention measures to control a bullous impetigo outbreak on a neonatal ward

<p>Abstract</p> <p>Background</p> <p>We describe an outbreak of Bullous Impetigo (BI), caused by a (methicillin susceptible, fusidic acid resistant) <it>Staphylococcus aureus</it> (SA) strain, <it>spa-</it>type t408, at the neonatal and gynaecology ward of the Jeroen Bosch hospital in the Netherlands, from March-November 2011.</p> <p>Methods</p> <p>We performed an outbreak investigation with revision of the hygienic protocols, MSSA colonization surveillance and environmental sampling for MSSA including detailed typing of <it>SA</it> isolates. <it>Spa</it> typing was performed to discriminate between the SA isolates. In addition, Raman-typing was performed on all t408 isolates.</p> <p>Results</p> <p>Nineteen cases of BI were confirmed by SA positive cultures. A cluster of nine neonates and three health care workers (HCW) with <it>SA</it> t408 was detected. These strains were MecA^-, PVL^-, Exfoliative Toxin (ET)A^-, ETB⁺, ETAD^-, fusidic acid-resistant and methicillin susceptible. Eight out of nine neonates and two out of three HCW t408 strains yielded a similar Raman type. Positive t408 HCW were treated and infection control procedures were reinforced. These measures stopped the outbreak.</p> <p>Conclusions</p> <p>We conclude that treatment of patients and HCW carrying a predominant SA t408, and re-implementing and emphasising hygienic measures were effective to control the outbreak of SA t408 among neonates.</p

Loop-Mediated Isothermal Amplification Test for Detection of Neisseria gonorrhoeae in Urine Samples and Tolerance of the Assay to the Presence of Urea

A loop-mediated isothermal amplification (LAMP) assay for open reading frame 1 (ORF1) of the glutamine synthetase gene of Neisseria gonorrhoeae was able to tolerate urea concentrations of ≤1.8 M, compared with a PCR assay that was functional at concentrations of <100 mM. The LAMP assay was as sensitive as the PCR assay while being faster and simpler to perform

Specific and Sensitive Detection of Neisseria gonorrhoeae in Clinical Specimens by Real-Time PCR

Early diagnosis of Neisseria gonorrhoeae infections is important with regard to patients' health and infectivity. We report the development of a specific and sensitive TaqMan assay for the detection of N. gonorrhoeae in clinical samples. The target sequence is a 76-bp fragment of the 5′ untranslated region of the opa genes that encode opacity proteins. A panel of 448 well-defined N. gonorrhoeae isolates was used to evaluate and optimize the assay. The method employs two minor-groove binding probes, one of them recognizing a newly identified sequence in the opa genes. Testing a large panel of related and unrelated microorganisms revealed that other Neisseria strains and other microorganisms tested negative in the opa test. With a lower detection limit of one genome per reaction, the opa test appeared more sensitive than both the COBAS AMPLICOR (Roche Diagnostics Nederland BV, Almere, The Netherlands) and a LightCycler 16S rRNA test. Analysis of a panel of 122 COBAS AMPLICOR-positive samples revealed that 68% were negative in both the 16S rRNA test and the opa assay (confirming that the COBAS AMPLICOR test produces false positives), while 30% were positive in both assays. Three samples were opa positive and 16S rRNA negative, which may be due to the higher sensitivity of the opa assay. We conclude that the opa gene-based real-time amplification assay offers a sensitive, specific, semiquantitative, and reliable assay suitable for the detection of N. gonorrhoeae in clinical specimens and/or for confirmation of less specific tests

A Fast Real-Time Polymerase Chain Reaction Method for Sensitive and Specific Detection of the Neisseria gonorrhoeae porA Pseudogene

Ever since the advent of molecular methods, the diagnostics of Neisseria gonorrhoeae has been troubled by false negative and false positive results compared with culture. Commensal Neisseria species and Neisseria meningitidis are closely related to N. gonorrhoeae and may cross-react when using molecular tests comprising too-low specificity. We have devised a real-time polymerase chain reaction (PCR), including an internal amplification control, that targets the N. gonorrhoeae porA pseudogene. DNA was automatically isolated on a BioRobot M48. Our subsequent PCR method amplified all of the different N. gonorrhoeae international reference strains (n = 34) and N. gonorrhoeae clinical isolates (n = 176) but not isolates of the 13 different nongonococcal Neisseria species (n = 68) that we tested. Furthermore, a panel of gram-negative bacterial (n = 18), gram-positive bacterial (n = 23), fungal (n = 1), and viral (n = 4) as well as human DNA did not amplify. The limit of detection was determined to be less than 7.5 genome equivalents/PCR reaction. In conclusion, the N. gonorrhoeae porA pseudogene real-time PCR developed in the present study is highly sensitive, specific, robust, rapid and reproducible, making it suitable for diagnosis of N. gonorrhoeae infection