## 4 Discussion  
EFB is endemic in most parts of the world [61; 62] except New Zealand [62]. For a long time the effects of the disease on colonies health have been underestimated and the prevalence has increased in the last decades in many countries such as Switzerland, UK, Netherlands and others [63; 64; 65; 66; 67; 68]. AFB disease is present wherever honey bees are reared and its economic impact is still one of the most important across brood diseases [69]. According to [PERSON] [5] two subspecies exist, belonging to four ERIC genotypes (ERIC I-IV), but only P. I. larvae (genotypes ERIC I and ERIC II) can be frequently isolated from foupl brood diseased colonies in Europe and on the American continent. The first EU-wide epidemiological dataset regarding fouplropods were obtained in 2012-2013, when 17 Member States took part to the first active epidemiological surveillance program on honeybee colony mortality in Europe (EPILOBEE) [66; 67; 68]. The overall clinical prevalence of AFB and EFB in 14 Member States was, respectively, lower than 12% for AFB and did not exceed 5% for EFB. In Italy, 1682 colonies have been put under observation in the EPILOBEE project: in regard to AFB, during the experimental period, the prevalence ranged from 2.7% before wintertime; 0% after wintertime to 2.2% during the active season. Similarly, in regard to EFB, the prevalence observed in Italy was 0% before wintertime and during the season and 1.1% after wintertime [68]. The Viterbo province presents 10,201 honeybee colonies, distributed in 169 apiaries (Italian National Bekekeeping Registry--December 2014). During our study, 979 colonies were monitored, the equivalent of 9.6% of the total amount of colonies in the whole province territory. The obtained prevalence of 5.1% for AFB and of 4.5% for EFB on 491 untreated colonies is the first data ever reported in Central Italy involving a substantial number of honey bee colonies. The majority of outbreaks occurred during spring (March-May 2014) when the brood coverage in colonies is developing and an imbalance between the number of larvae and nurse bees as well as food shortages, particularly of protein, can play an important role [69; 70]. Worldwide, the control of AFB and EFB relies on different strategies. In many countries, quarantine, incineration of symptomatic colonies or, alternatively, use of the shook swarm technique are considered priority measures regulated by health laws. _L. plantarum_ is widely used in the food industry. It is, in fact, a versatile bacterium living in several ecological niches, ranging from vegetable and plant fermentations to the human gastrointestinal tract. The EU Commission, by means of Regulation (EU) N. 93/2012, approves the use of _Lactobacillus plantarum_ (strains DSM 8862 and DSM 8866) as a feed additive for all animal species, without maximum residue limit. Several LAB species isolated from honey bees showed in laboratory conditions beneficial health effects at the individual bee level respect the AFB infection [52; 56; 71; 72], but in \begin{table}
\begin{tabular}{c c c} \hline \hline
**Day** & **Obs. Value** & **\(p\)-Value** \\ \hline
34 & 4.513 & 0.034 \\
36 & 3.078 & 0.079 \\
60 & 0.948 & 0.330 \\
65 & 3.254 & 0.071 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Log-Rank test values of EFB survival curves applied at different time-frames. literature no optimistic results have ever been obtained from trials on colonies [73]. The results obtained with the _L. plantarum_ strain tested in our study underline that, at the moment, the best practice to avoid the spread of AFB and the development of antibiotic resistance is the incineration of symptomatic colonies [10].