The development of chronic inflammatory periodontal diseases is strongly correlated with the growth and maturation of subgingival bacterial colonies. Consequently a major preventive goal should be the control of plaque formation. We conducted a randomized, controlled trial to examine the short-term effect of an intensive instructional program without professional prophylaxis on the gingival health of 240, 11-14 year old school children. Plaque index (PlI), gingival index (GI), bleeding index (BI) and probing pocket depth (PD) were examined 4 x by 1 examiner blinded to the instruction. During the period of instruction, subjects in the experimental groups were involved in a plaque and gingivitis prevention program provided in separate educational sessions. One of the experimental groups (E-1; n = 80) was provided with a new toothbrush, toothpaste and instruction while the second experimental group (E-2; n = 80) was provided with toothbrush, toothpaste, dental floss and instruction. In the control group (C; n = 80) only dental examinations were provided: no preventive program or oral health measures were conducted. Examinations were conducted every 3 months during the instructional period and at 6 months following the completion of the active preventive programme. During the experimental period there was a significant decrease (p < 0.001) in the mean PlI, GI and BI of the experimental groups following the program while in controls there was a slight but not significant increase of mean values (p > 0.05). During the preventive program experimental groups exhibited small but not significant (p > 0.05) reductions of PD. Experimental group 1 showed similar PlI, GI, BI and PD scores as experimental group 2 during the study. After the instructional program was completed and a period of 6 months had passed, there was a large and significant (p < 0.001) increase of mean PlI, GI and BI scores in both experimental groups back to the baseline levels. We conclude that a short-term preventative program without professional instrumentation induces a transient improvement of gingival health of schoolchildren but only during the instructional period. The maintenance of improved gingival health over longer time periods requires prolonged, repeated instruction by professionals. These measures may be difficult to institute and are of questionable cost-effectiveness.

Xanthomonas euvesicatoria phage KΦ1, a member of Myoviridae family, was isolated from the rhizosphere of pepper plants showing symptoms of bacterial spot. The phage strain expressed antibacterial activity to all X. euvesicatoria strains tested and did not lyse other Xanthomonas spp., nor other less related bacterial species. The genome of KΦ1 is double-stranded DNA of 46.077 bp including 66 open reading frames and an average GC content of 62.9%, representing the first complete genome sequence published for a phage infecting xanthomonads associated with pepper or tomato. The highest genome similarity was observed between phage KΦ1 and the Xanthomonas oryzae pv. oryzae specific phage OP2. On the other hand, when compared with other members of the genus Bcep78virus, the genome similarity was lower. Forty-four (67%) predicted KΦ1 proteins shared homology with Xanthomonas phage OP2, while 20 genes (30%) were unique to KΦ1. Phage KΦ1, which is chloroform resistant and stable in different media and in the pH range 5-11, showed a high titer storage ability for at least 2 years at +4°C. Copper-hydroxide and copper-oxychloride reduced phage activity proportionally to the used concentrations and the exposure time. UV light was detrimental to the phage strain, but skim milk plus sucrose formulation extended its survival in vitro. The phages survived for at least 7 days on the surface of pepper leaves in the greenhouse, showing the ability to persist on the plant tissue without the presence of the host bacterium. Results of three repeated experiments showed that foliar applications of the unformulated KΦ1 phage suspension effectively controlled pepper bacterial spot compared to the standard treatment and the untreated control. The integration of the phage KΦ1 and copper-hydroxide treatments resulted in an increased efficacy compared to the copper-hydroxide alone.

Sooty blotch and flyspeck (SBFS) fungi colonize the surface wax layer of the fruit of apple, pear, persimmon, banana, orange, papaya, and several other cultivated tree and vine crops. In addition to colonizing cultivated fruit crops, SBFS fungi also grow on the surfaces of stems, twigs, leaves, and fruit of a wide range of wild plants. The disease occurs worldwide in regions with moist growing seasons. SBFS is regarded as a serious disease by fruit growers and plant pathologists because it can cause substantial economic damage. The smudges and stipples of SBFS often result in downgrading of fruit from premium fresh-market grade to processing use. This review describes the major shifts that have occurred during the past decade in understanding the genetic diversity of the SBFS complex, clarifying its biogeography and environmental biology, and developing improved management strategies.

The molecular identification and characterization of phytoplasmas from infected grapevines in four locations in Serbia are reported. Phytoplasmas were detected and identified by restriction fragment length polymorphism (RFLP) analysis of polymerase chain reaction (PCR) amplified 16S rDNA. Grapevine yellows were associated with three molecularly distinguishable phytoplasmas: Flavescence dore´e phytoplasmas (elm yellows group: 16SrV-C subgroup) were present only in the Ž upa Aleksandrovac region; Bois noir phytoplasmas (stolbur group: 16SrXII-A subgroup) were detected in the other surveyed regions; a mixed infection of European stone fruit yellows (apple proliferation group: 16SrX-B subgroup) and Bois noir phytoplasmas was identified in one sample. A finer molecular characterization by RFLP analysis of rpS3 and SecY genes of Flavescence dore´e phytoplasmas from Ž upa Aleksandrovac confirmed that the Serbian genotype is indistinguishable from a strain from the Veneto region, Italy. Characterization of the tuf gene of Bois noir phytoplasmas showed lack of amplification of samples from Erdevik. HpaII profiles of tuf gene PCR products of samples from Pali and Radmilovac were identical, and were indistinguishable from one of the two profiles produced by samples from Italian grapevines used as reference strains.

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