First Report of Leaf Spot of Kentucky Bluegrass (Poa pratensis) Caused by Nigrospora oryzae in Ontario

Kentucky bluegrass (Poa pratensis L.) is an important cool-season perennial grass in Ontario. It is native to Europe and can form an attractive and durable turf. In late September 2011, distinct leaf spots were observed on a Kentucky bluegrass lawn in Guelph, ON. Symptoms ranged from small lesions that were chocolate brown and oval or circular up to withered leaves. On potato dextrose agar (PDA) amended with streptomycin and tetracycline, a fungus was consistently recovered from symptomatic leaf samples after surface sterilization for 1 min in 1% sodium hypochlorite. On PDA, cultures were gray with an irregularly distributed, wool-like, fastgrowing aerial mycelium, showing a dark back side as the colony changed to darker brown after 7 days at 25°C. On diseased leaves, conidia were observed after moist incubation, borne on a hyaline vesicle at the tip of each conidiophore. Conidia were single celled, black, smooth, spherical, and 11.2 to 15.5 μm (average 13.8 μm) in diameter. The pathogen was identified as Nigrospora oryzae based on previous descriptions (1,2). Genomic DNA was extracted from a representative isolate, 11201, and the internal transcribed spacer (ITS) region of the ribosomal DNA was amplified by the primers ITS1 and ITS4 (4). The ITS sequence showed 99.8% similarity in the overlapping 508-bp portion with N. oryzae (GenBank No. GQ328855). Pathogenicity tests were performed in the laboratory with the isolate on 3-week-old, sand-based, Magenta box-grown plants of three cool-season turfgrass species, P. pratensis, Agrostis stolonifera, and Lolium perenne, by inoculating with fungal plugs. A 5-mm-diameter plug from 5-day-old PDA cultures was directly placed onto leaves in each of four replicate boxes per species, and then removed after 48 h of incubation. Plants treated with sterile agar plugs served as controls. Magenta boxes containing treated turf were covered loosely with their plastic lids and incubated at 23°C. Three days after inoculation and 1 day after inoculum removal, typical chocolate brown spots were observed on inoculated leaves from all three turfgrass species, but no symptoms were seen on agar plug-treated control plants. Koch's postulates were fulfilled by reisolation of N. oryzae from diseased leaves. The pathogenicity tests were carried out twice with the same results. This is an indication that N. oryzae causing leaf spot of Kentucky bluegrass in Ontario was not hostspecific, and could potentially affect other cool-season turfgrass species. Review of the literature revealed that N. oryzae is known as a pathogen on maize, rice, sorghum, cotton, weeds, and several other hosts, but has not been reported on any species of turfgrass (3). To our knowledge, this is the first report of N. oryzae infecting Kentucky bluegrass in Ontario or worldwide. References: (1) M. B. Ellis. Dematiaceous Hyphomycetes, CAB, Kew, Surrey, England, 1971. (2) H. J. Hudson. Trans. Brit. Mycol. Soc. 46:355, 1963. (3) R. W. Smiley et al. Compendium of Turfgrass Diseases. 3rd ed. APS Press, St Paul, MN, 2005. (4) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

Long-term impact of liver transplantation on respiratory function and nutritional status in children and adults with cystic fibrosis

Early liver transplant (LT) has been advocated for patients with cystic fibrosis liver disease (CFLD) and evidence of deterioration in nutritional state and respiratory function to prevent further decline. However, the impact of single LT on long-term respiratory function and nutritional status has not been adequately addressed. We performed a retrospective analysis of the outcomes of 40 (21 adult/19 pediatric) patients with CFLD transplanted between 1987 and 2009 with median follow-up of 47.8 months (range 4-180). One and five-year actuarial survival rates were 85%/64% for adult and 90%/85% for pediatric LT cohorts, respectively. Lung function remained stable until 4 years (FEV(1) % predicted; pretransplant 48.4% vs. 45.9%, 4 years posttransplant) but declined by 5 years (42.4%). Up to 4 years posttransplant mean annual decline in FEV(1) % was lower (0.74%; p = 0.04) compared with the predicted 3% annual decline in CF patients with comorbidity including diabetes. Number of courses of intravenous antibiotics was reduced following LT, from 3.9/year pretransplant to 1.1/year, 5 years posttransplant. Body mass index was preserved posttransplant; 18.0 kg/m(2) (range 15-24.3) pretransplant versus 19.6 kg/m(2) (range 16.4-22.7) 5 years posttransplant. In conclusion, LT is an effective treatment for selected patients with cirrhosis due to CFLD, stabilizing aspects of long-term lung function and preserving nutritional status.

Prevention of Staphylococcus aureus biofilm formation and reduction in established biofilm density using a combination of phage K and modified derivatives

AIMS

To investigate the ability of a mixture of phage K and six of its modified derivatives to prevent biofilm formation by Staphylococcus aureus and also to reduce the established biofilm density.

METHODS AND RESULTS

The bioluminescence-producing Staph. aureus Xen29 strain was used in the study, and incubation of this strain in static microtitre plates at 37°C for 48 h confirmed its strong biofilm-forming capacity. Subsequently, removal of established biofilms of Staph. aureus Xen29 with the high-titre phage combination was investigated over time periods of 24 h, 48 h and 72 h. Results suggested that these biofilms were eliminated in a time-dependent manner, with biofilm biomass reduction significantly greater after 72 h than after 24-48 h. In addition, initial challenge of Staph. aureus Xen29 with the phage cocktail resulted in the complete inhibition of biofilm formation over a 48-h period with no appearance of phage resistance.

CONCLUSIONS

In general, our findings demonstrate the potential use of a modified phage combination for the prevention and successful treatment of Staph. aureus biofilms, which are implicated in several antibiotic-resistant infections.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study highlights the first use of phage K for the successful removal and prevention of biofilms of Staph. aureus.

Staged abdominal closure after small bowel or multivisceral transplantation

Following paediatric SBMT, size discrepancy between the recipient's abdomen and the graft may lead to ACS, graft dysfunction, and death. We report our experience with SAC in these patients. Between 04/1993 and 03/2009, 57 children underwent 62 SBMTs. When abdominal wall tension seemed excessive for safe PAC, SAC was performed, using a Silastic® sheet and a vacuum occlusive dressing. Transplantations with SAC (23 combined liver and small bowel [CLB]) were compared with those with PAC [14 ISB and 25 CLB]. Indications for transplantation, preoperative status (after stratification for ISB/CLB transplants), age at transplantation, donor-to-recipient weight ratio, reduction in bowel and/or liver, and incidence of wound complications were not different in both groups. Post-operative intubation, stay in intensive care unit, and hospital stay were prolonged after SAC. Two deaths were related to ACS after PAC, none after SAC. Since 2000, one-yr patient survival is 73% after ISB transplantation and 57% vs. 75% after CLB transplantation with PAC vs. SAC, respectively (NS). SAC safely reduces severe ACS after paediatric SBMT and can be combined with graft reduction for transplantation of small recipients.

How children die: classifying child deaths

AIM

To validate a descriptive tool for the causes of child death, which was designed to circumvent problems posed by the analysis of a confidential enquiry.

METHOD

3 participants from different healthcare backgrounds used clinical data, including the entries on the medical certificate of the cause of death, to classify the root cause of 783 deaths from the Confidential Enquiry into Maternal and Child Health child death review. A bespoke hierarchical system was used. Unanimity of allocation within categories and inter-rater and intra-rater agreement were assessed. Two methods for treating disagreements were compared by assessing their effect upon the apparent incidence of different causes of death.

RESULTS

The participants were most consistent in grouping deaths due to trauma, malignancy and sudden infant death. Each was highly consistent in allocating cases to groups (κ 0.85-0.99), but the agreement between participants, although "good", was worse (κ 0.66-0.78). The greatest number of discrepancies was between diseases identified as congenital by the doctor and as chronic medical conditions by others. The method for treating disagreement between participants does not affect the commonest cause of death (trauma) but alters the ranking of the subordinate causes.

CONCLUSION

Agreement within diagnostic categories might be improved by greater training of assessors in the use of the technique. This level of performance compares well with that of other coding systems upon their target groups.

Why children die: avoidable factors associated with child deaths

AIM

To describe the avoidable factors associated with child deaths identified by a confidential enquiry.

METHOD

In the Centre for Maternal and Child Enquiries confidential enquiry, a sample (13%) of cases was subjected to case note review by multidisciplinary panels attempting to identify avoidable factors associated with the deaths. Cases were selected blindly but in equal numbers from predetermined age bands and participating regions. The anonymised records were reviewed in regions remote to where the child lived and died. Panel composition, conduct and reporting were standardised.

RESULTS

119 of 126 cases reviewed by enquiry panels had sufficient information to determine avoidable factors. These cases were comparable with the whole dataset in terms of sex and causes of death. 31 (26%) of 119 had avoidable factors that were predominantly related to individuals or agencies with a direct responsibility to the child. 51 (43%) of 119 were defined as potentially avoidable. In all, 130 factors were considered in relation to these 82 cases, and 64% of the factors were healthcare related. Avoidable factors were more likely where life-limiting illness was not present. Recurring avoidable factors included failure to recognise serious illness at the point of presentation and death occurring in children who had been lost to follow-up.

CONCLUSION

Child Death Overview Panels now have the responsibility to review child deaths using similar methods but relying upon data forms rather than the case record. Analysis of contributory factors on a national scale has the potential to improve understanding of why children die and indicate strategies to reduce child mortality.