Differential detection of Bartonella species and strains in cat scratch disease diagnostics by polymerase chain reaction amplification of 16S ribosomal RNA gene.

Cat scratch disease (CSD) has been difficult to diagnose in animals because of the protracted clinical course of infection and the quiescent phases when the microbial culprit lies dormant. The causative agent in CSD appears to be multiple species and strains of Bartonella. Using polymerase chain reaction (PCR) techniques for amplification of highly variable regions of the 16S ribosomal RNA (rRNA) gene sequence, a very sensitive species- and strain-specific assay for CSD-causing Bartonella species was developed. PCR primers were designed to specifically amplify the 16S rRNA gene of Bartonella species but not of other microbial pathogens. This initial PCR was multiplexed with a universal primer set, based on conserved sequence regions in the 16S rRNA gene, that provides a 162-bp fragment in all species tested. Subsequently, 3 distinct nested PCR primer sets enabled the individual amplification and specific detection of Bartonella henselae type 1, B. henselae type II, and B. clarridgeae. Thus, this 2-step PCR procedure enabled the sensitive detection and identification of these species and the B. henselae genotype by exploiting minor sequences differences. Verification of these results were demonstrated with both sequencing and ligase chain reaction techniques. The diagnostic usefulness of this CSD test has been demonstrated by the analysis of specimens from control and infected cats. The diagnosis was confirmed and the specific B. henselae strain was correctly identified in peripheral blood specimens obtained from control and strain-specific CSD-infected cats. Such an accurate and sensitive diagnostic tool for the detection and identification of CSD causative agents should be a useful for the medical, veterinary, and scientific communities.

Evaluation and use of a nested polymerase chain reaction assay in cats experimentally infected with Bartonella henselae genotype I and Bartonella henselae genotype II.

Cats have been shown to be infected with Bartonella henselae genotype I, B. henselae genotype II, and B. clarridgeiae. Feline bartonellosis infections and the strains involved in these infections are important in both veterinary and human medicine. Nucleic acid amplification methods such as polymerase chain reaction (PCR) are being used in both research and diagnostics as tools for understanding many infectious diseases. Bartonella bacteremia in cats is detected by blood culture; however, because of the limitations of culture (delayed turnaround time and sensitivity limits), PCR may be a more efficient method for identifying infected cats. Three distinct PCR assays that could differentiate among B. henselae genotype I, B. henselae genotype II. and B. clarridgeiae were developed and used to detect as few as 3.2 organisms. Fourteen cats experimentally infected with B. henselae genotype I and B. henselae genotype II were followed by bacterial culture and PCR through the course of infection, including periods of primary and relapsing bacteremia. The PCR assay was positive in 11 of the 14 cats for periods of 1-9 weeks after culture became negative. Of the 223 blood specimens that were culture negative, the PCR assay was positive in 38 (17%) of the specimens. Two of the 14 cats developed relapsing bacteremia. The 2 B. henselae genotypes were amplified in the cats and the bacteremic phase of these infections as determined by PCR lasted for a longer period than previously determined by culture. Using laboratory assays such as PCR to understand the strains involved in feline bartonellosis and the course of the infection is important in the understanding of these zoonotic agents.

Assessing elderly acute care services: improving quality amid chaos.

Elderly service delivery within the medical-surgical division of a large midwestern tertiary care center was assessed to explore how to meet better the special needs and address the complex situations that older adults present. Twenty-seven nursing staff members working in the four medical-surgical units and the medical intensive care unit were interviewed using participant observation and unstructured interviewing methods as they delivered care to older adults. The following categories emerged from the qualitative data analysis: problems related to the care of older adults, causes of confusion, effective and potentially effective interventions for older patients, and staff educational needs. A major suggestion was to develop an interdisciplinary seniors team to provide consultation on issues related to older adults to nursing staff, medical staff, and other interdisciplinary staff involved in patient care. The team would evaluate the appropriateness of interventions, equipment, and personnel use related to older adults as well as identify and develop quality assurance activities to monitor and evaluate the care delivered to older adults.