Hospital-acquired Sphingomonas paucimobilis Infection in a Neonate: A Case Report

Introduction: The organism Sphingomonas paucimobilis formerly known as Pseudomonas paucimobilis is a strict aerobe, motile, non-spore forming, non-fermentative, Gram-negative bacillus, characterized by catalase and oxidase activities. It is an opportunistic pathogen that causes infection in healthy and immunocompromised individuals. Sphingomonas paucimobilis is ubiquitous and has been isolated from diverse sources including the hospital environment. Presentation of Case: We describe the clinical characteristics, manifestations, laboratory findings and management of hospital-acquired Sphingomonas paucimobilis sepsis in a neonate, delivered through caesarean section and brought in from postnatal ward to special care baby unit of the University of Abuja Teaching Hospital, Gwagwalada, Abuja, Nigeria. Discussion: The laboratory findings showed normal values for complete blood count, electrolytes, urea and creatinine but positive blood culture. Sphingomonas paucimobilis isolated from the blood was susceptible to Imipenem, Ampicilin-sulbatam, Azithromycin, Lincomycin, Ofloxacin, Ciprofloxacin and Sparfloxacin but resistant to Cefuroxime, Ceftazidime, Augumentin and Ampicillin. The isolation of this organism from the newborn whose laboratory tests were within normal acceptable values, and from the hospital environment is a case of hospital-acquired infection. The patient recovered and was discharged because of adequate treatment by the managing team and also low virulence of this organism. Conclusion: The study thereby recommends adequate and consistent cleaning of the newborn and maternity units of the hospital, in particular, the entire hospital equipment and its environment using a potent disinfectant to minimize the risk of hospital-acquired infections.

Rapid Detection of Pectolytic Erwinia sp. in Aglaonema sp.

The purpose of this research was to develop a rapid microplate assay for detecting and presumptively identifying pathogenic pectolytic Erwinia sp. in ornamental propagative stock and to readily distinguish them from nonpathogenic bacteria associated with Aglaonema. The assay was developed by modifying an existing crystal violet-sodium polypectate (CVP) medium to visualize the depolymerization of pectate by addition of bromcresol purple (BCP), then acidifying with a dilute hydrochloric acid (HCl) solution. The assay was sufficiently sensitive to detect latent (symptomless) infections in small sections of leaf or stem tissue. Based on inoculum titration assays, 40 to 600 colony-forming units (CFU) of Erwinia chrysanthemi (Burkholder et al.) were required to produce symptoms in Aglaonema stems and leaves, respectively. The microplate assay was able to detect the pathogen at low levels (40 to 60 CFU) in tissue segments of ≈1 cm2. In tests of bacterial strains isolated from 211 samples from Aglaonema `Silver Queen', `Emerald Beauty', and `San Luis' grown in Hawaii, only the pectolytic and pathogenic Erwinia sp. reacted positively in the microplate assay. Other bacteria associated with Aglaonema, including Pseudomonas paucimobilis (Holmes), P. vesicularis (Galarneault and Leifson), and nonpectolytic Erwinia sp., were not detected by the assay. Pectolytic strains of Ralstonia (Pseudomonas) solanacearum (Smith) were differentiated from pectolytic Erwinia sp. by the yellow color that developed in wells of the latter strains after acidification of the medium with dilute HCl. The test is visual and can be performed with minimal equipment and cost.

Cloning and Sequencing of theSphingomonas (Pseudomonas)paucimobilis Gene Essential for the O Demethylation of Vanillate and Syringate

ABSTRACT Sphingomonas (Pseudomonas)paucimobilis SYK-6 is able to grow on 5,5′-dehydrodivanillic acid (DDVA), syringate, vanillate, and other dimeric model compounds of lignin as a sole carbon source. Nitrosoguanidine mutagenesis of S. paucimobilis SYK-6 was performed, and two mutants with altered DDVA degradation pathways were isolated. The mutant strain NT-1 could not degrade DDVA, but could degrade syringate, vanillate, and 2,2′,3′-trihydroxy-3-methoxy-5,5′-dicarboxybiphenyl (OH-DDVA). Strain DC-49 could slowly assimilate DDVA, but could degrade neither vanillate nor syringate, although it could degrade protocatechuate and 3-O-methylgallate. A complementing DNA fragment of strain DC-49 was isolated from the cosmid library of strain SYK-6. The minimum DNA fragment complementing DC-49 was determined to be the 1.8-kbp insert of pKEX2.0. Sequencing analysis showed an open reading frame of 1,671 bp in this fragment, and a similarity search indicated that the deduced amino acid sequence of this open reading frame had significant similarity (60%) to the formyltetrahydrofolate synthetase ofClostridium thermoaceticum.