Incidence of bacterial coinfection with respiratory syncytial virus bronchopulmonary infection in pediatric inpatients.

Bacterial coinfection occurs in pediatric bronchopulmonary infections caused by respiratory syncytial virus (RSV), but the incidence is uncertain. Our subjects are 188 pediatric inpatients having RSV bronchopulmonary infection in two hospitals in Chiba Prefecture between 2005 and 2007. On admission, antigen detection kits using nasopharyngeal aspirate were performed to detect RSV infection and washed sputum bacterial culture was performed to detect bacterial infection. Of the 188 pediatric inpatients with RSV bronchopulmonary infection, 95 (50.5%) patients were aged less than 1 year, 57 (30.3%) were aged 1-2 years, and 36 (19.1%) were aged 2 years or more. Thirty-six (19.1%) patients were associated with bronchial asthma attacks. Pathogenic bacteria were predominantly isolated from 43.6% of the patients. The three most frequently isolated bacteria were Haemophilus influenzae (43.9%), Streptococcus pneumoniae (36.6%), and Moraxella catarrhalis (29.3%). We found that 38.9% of H. influenzae strains were ß-lactamase-nonproducing ampicillin-resistant strains. All S. pneumoniae strains were penicillin G (PcG) sensitive. However, 21.9% of S. pneumoniae strains showed PcG minimum inhibitory concentration values of 2 µg/ml. RSV bronchopulmonary infections in hospitalized children are often associated with antimicrobial-resistant bacterial infection in their lower airways. These results indicate that we should be aware of bacterial coinfections in the management of pediatric inpatients with RSV bronchopulmonary infection.

[Incidence of community-acquired pneumonia and pneumococcal pneumonia, among children in Chiba City, Japan].

Population-based studies on community-acquired pneumonia (CAP) are rare in Japan. Among 984 Chiba City children admitted with CAP to 19 local hospitals in 2005, 854 were younger than 5 years old. The annual CAP incidence among children < 5 years old was 19.7 per 1,000. Five, 4 of whom were under 5 years old, had pneumococcus isolated from blood. The incidence of CAP with pneumococcal bacteremia was 9.21 per 100,000 among those < 5 years old.

Biotransformation of arsenic species by activated sludge and removal of bio-oxidised arsenate from wastewater by coagulation with ferric chloride.

The potential of activated sludge to catalyse bio-oxidation of arsenite [As(III)] to arsenate [As(V)] and bio-reduction of As(V) to As(III) was investigated. In batch experiments (pH 7, 25 degrees C) using activated sludge taken from a treatment plant receiving municipal wastewater non-contaminated with As, As(III) and As(V) were rapidly biotransformed to As(V) under aerobic condition and As(III) under anaerobic one without acclimatisation, respectively. Sub-culture of the activated sludge using a minimal liquid medium containing 100mg As(III)/L and no organic carbon source showed that aerobic arsenic-resistant bacteria were present in the activated sludge and one of the isolated bacteria was able to chemoautotrophically oxidise As(III) to As(V). Analysis of arsenic species in a full-scale oxidation ditch plant receiving As-contaminated wastewater revealed that both As(III) and As(V) were present in the influent, As(III) was almost completely oxidised to As(V) after supply of oxygen by the aerator in the oxidation ditch, As(V) oxidised was reduced to As(III) in the anaerobic zone in the ditch and in the return sludge pipe, and As(V) was the dominant species in the effluent. Furthermore, co-precipitation of As(V) bio-oxidised by activated sludge in the plant with ferric hydroxide was assessed by jar tests. It was shown that the addition of ferric chloride to mixed liquor as well as effluent achieved high removal efficiencies (>95%) of As and could decrease the residual total As concentrations in the supernatant from about 200 microg/L to less than 5 microg/L. It was concluded that a treatment process combining bio-oxidation with activated sludge and coagulation with ferric chloride could be applied as an alternative technology to treat As-contaminated wastewater.

[Studies of treatment for Haemophilus influenzae type b meningitis in children].

We summarize 41 cases of bacterial meningitis in the last 11 years caused by Haemophilus influenzae. All isolates were serotype b strain (Hib). Initial chemotherapy was started with ceftriaxone (CTRX) in 22 cases, ampicillin plus cefotaxime (CTX) in 9, CTRX plus panipenem/betamipron in 5, and CTX in 2. Some 31 cases were treated mainly with CTRX. Although therapeutic antibiotics showed good susceptibility for isolates, 8 complicated cases (19.5%) occurred. Sequalae were observed in 7 (17.1%) but none were fatal. Five strains with elevated MIC of CTX (0.12 to 1 microg/mL) recovered after 2001, and 3 of 5 strains also showed elevated MIC of CTRX (0.12 to 0.5 microg/mL), but all were cured completely with CTRX. At present, no treatment failures due to antibiotic resistance have been observed, and CTRX remains suitable as initial therapy for Hib meningitis. A decline in susceptibility for third-generation cephalosporin against beta-lactamase-nonproducing ampicillin-resistant H. influenzae is emerging, however, so it will be necessary to consider combination therapy with CTRX given the foreseeable trend in MICs.

Influence of water and sediment quality on benthic biota in an acidified river.

Water and sediment quality and benthic biota were investigated in all seasons during three years in the River Akagawa that receives the effluent from a mine drainage treatment plant at its upstream site. The upper reaches kept the low pH, the comparatively high concentrations of metals and a large amount of iron deposited on the riverbed. The predominant macroinvertebrates were Protonemura sp., Capnidae, Nemoura sp. and Chironomidae in the upper and middle reaches. In the lowest reaches, the community structure of the macroinvertebrate changed into Chironomidae, Trichoptera (Hydropsychidae) and Ephemeroptera (Baetis sp.) as the pH was increased. From the results of multivariate analyses, it was found that the restoration of pH and attached algae and the increase in the concentrations of nutrients and organic matter promoted the inhabitation of Chironomidae and Hydropsychidae, whereas the dissolved metals in the river water inhibited the inhabitation of these families. Moreover, the sedimentation of metals would cause a severe damage to the inhabitation of Hydropsychidae compared with that of Chironomidae.