A case of facial cellulitis caused by group B streptococcus in an extremely low birthweight infant.

Group B streptococcus (GBS) is an important pathogen that causes neonatal sepsis and meningitis, which have high mortality and morbidity. Cellulitis is a rare presentation of late-onset neonatal GBS infection. We report the case of an extremely low birthweight infant with facial cellulitis caused by late-onset GBS infection. A 590-g male neonate was delivered by Cesarean section at 23 gestational weeks due to intrauterine GBS infection. Although he was effectively treated with 2 weeks of antimicrobial therapy for early-onset GBS sepsis, he subsequently developed facial and submandibular cellulitis caused by GBS at 44 days of age. He was treated with debridement and antibiotic therapy, and after 2 months his facial involvement had improved, but cosmetic issues remained. Neonatal GBS infection requires a prompt sepsis workup followed by the initiation of empiric antibiotic therapy. Additionally, lifesaving surgical debridement is sometimes necessary for cellulitis, even in premature infants.

Comparative analysis of the catalytic components in the archaeal dye-linked L-proline dehydrogenase complexes.

Two types of hetero-oligomeric dye-linked L-proline dehydrogenases (α4ß4 and αßγδ types) are expressed in the hyperthermophilic archaea belonging to Thermococcales. In both enzymes, the ß subunit (PDHß) is responsible for catalyzing L-proline dehydrogenation. The genes encoding the two enzyme types form respective clusters that are completely conserved among Pyrococcus and Thermococcus strains. To compare the enzymatic properties of PDHßs from α4ß4- and αßγδ-type enzyme complexes, eight PDHßs (four of each type) from Pyrococcus furiosus DSM3638, Pyrococcus horikoshii OT-3, Thermococcus kodakaraensis KOD1 JCM12380 and Thermococcus profundus DSM9503 were expressed in Escherichia coli cells and purified to homogeneity using one-step Ni-chelating chromatography. The α4ß4-type PDHßs showed greater thermostability than most of the αßγδ-type PDHßs: the former retained more than 80 % of their activity after heating at 70 °C for 20 min, while the latter showed different thermostabilities under the same conditions. In addition, the α4ß4-type PDHßs utilized ferricyanide as the most preferable electron acceptor, whereas αßγδ-type PDHßs preferred 2, 6-dichloroindophenol, with one exception. These results indicate that the differences in the enzymatic properties of the PDHßs likely reflect whether they were from an αßγδ- or α4ß4-type complex, though the wider divergence observed within αßγδ-type PDHßs based on the phylogenetic analysis may also be responsible for their inconsistent enzymatic properties. By contrast, differences in the kinetic parameters among the PDHßs did not reflect the complex type. Interestingly, the k cat value for free α4ß4-type PDHß from P. horikoshii was much larger than the value for the same subunit within the α4ß4-complex. This indicates that the isolated PDHß could be a useful element for an electrochemical system for detection of L-proline.