Nasopharyngeal colonization at birth and the development of early-onset neonatal sepsis

Background Neonatal sepsis is one of the major causes of morbidity and mortality in neonates. Exposure to maternal bacteria during pregnancy or delivery allows for colonization of the normal upper airway. Such bacteria become the major ecological species in the infant. If the colonizing bacteria invade the bloodstream, early-onset neonatal sepsis (EONS) could occur. Objective To evaluate for an association between colonization of the newborn nasopharynx and EONS, as well as for agreement between nasopharyngeal swab culture and blood culture isolate results. Methods This prospective cohort study was conducted in Dr. Wahidin Sudirohusodo General Hospital and Ibnu Sina Hospital, Makassar, South Sulawesi. Nasopharyngeal swab culture was taken within 2 hours of life from newborns who met the inclusion criteria, then they were followed up for signs of EONS. Blood culture was taken from subject with EONS. Results Of the 100 newborns, 69 (69%) had nasopharyngeal bacterial colonization, of whom 5.8% (4/69) experienced EONS. Of the remaining 31 (31%) without colonization, 9.7% (3/31) experienced EONS. There was no significant difference in frequency of EONS between newborns with and without nasopharyngeal colonization. Although Gram-negative bacteria were predominant among colonized newborns, there was no significant difference to numbers of Gram-positive bacteria as a causative agent of EONS. Only one patient with EONS had the same bacterial species in both the nasopharynx and blood culture isolate. Conclusion Newborn nasopharyngeal colonization at birth is not associated with EONS.

Molecular Characterization of a Catalase-Negative Staphylococcus aureus Blood Culture Isolate: TABLE 1

Here we report a catalase-negative methicillin-sensitiveStaphylococcus aureusisolate collected from a blood culture. Sequencing through the gene encoding catalase,katA, demonstrated a 2-bp insertion. The resulting frameshift mutation generates a protein that has lost 26 amino acids (aa) at its C-terminal domain.

Development of a sensitive, multiplexed immunoassay using xMAP beads for detection of serotype-specific Streptococcus pneumoniae antigen in urine samples

In support of the surveillance of pneumococcal infections in the era of conjugate vaccines, a sensitive and specific multiplex immunoassay using xMAP beads has been developed for direct detection of pneumococcal serotype-specific polysaccharides in clinical samples, particularly urine. The assay was tested on panels of spiked urine specimens, clinical urine specimens and bacterial isolates. Each of the 14 serotypes in the multiplex assay can be detected to 0.1 ng purified polysaccharide ml−1, or less. Testing of a panel of urine specimens from patients with culture-confirmed pneumococcal or non-pneumococcal disease indicated that the multiplex assay is both sensitive and specific. The correct pneumococcal serotype was identified directly from urine in 46/58 (79.3 %) patients who had a contemporaneous blood culture isolate of a multiplex assay serotype. Furthermore, the specificity of the assay on this panel of samples was 99.3 % (145/146). This multiplex assay could be useful, in conjunction with the pneumococcal screening test Binax NOW, in urine for diagnosis of pneumococcal disease and the identification of the aetiological serotype, and potentially be of benefit in culture-negative patients.

Endocarditis caused by Propionibacterium species: a report of three cases and a review of clinical features and diagnostic difficulties

Propionibacterium species are members of the normal flora of skin and the mouth but their pathogenic potential is often overlooked. Three fatal cases of endocarditis caused by Propionibacterium species over an 8-year period are reported, and a review is presented of a further 33 cases from the world literature. In most cases, infection was protracted, with minimal signs in the early stages. Fourteen cases (42.4 %) involved native valves, 16 (48.5 %) involved prosthetic valves and three (9.1 %) were associated with other intracardiac prosthetic material. Intracardiac abscesses were commonly encountered, with Propionibacterium endocarditis occurring in 28.6 % of native valve infections and 52.9 % of prosthetic valve infections. A very high proportion of all of the cases (70.6 %) required surgical intervention. Several factors appeared to delay institution of appropriate therapy and may have contributed to abscess formation, including an indolent clinical course, negative or delayed culture results, and the tendency to consider this organism as a blood-culture contaminant. The authors recommend careful clinical evaluation before disregarding a blood-culture isolate of Propionibacterium spp. as a skin contaminant, and consideration of this bacterium as a potential cause of apparently culture-negative endocarditis.