## 4 Discussion  
Honeybees can be infected by three species of the _Nosema_ genus, i.e., _Nosema apis_, _N. ceranae_ and _N. neumanii_[3; 4; 5]. _Nosema apis_ was described in 1909 by the German biologist [PERSON] [3], _N. ceranae_ was originally detected in _Apis ceran_ in Asia in 1996 and again recently in _A. mellifera_[4], and _N. neumanni_ has presently only been observed in Uganda, but at a higher level than each of the other two _Nosema_ species [5]. Nevertheless, the course of these microglial infections is similar notwithstanding the species of the pathogens causing the infection. Pathogens from the _Nosema_ genus have a high tropism for the ventricular epithelium cells [24]. After the spores' ingestion, a spore polar tube punctures the epithelial cells and infectious sporoplasm enters the host's midgut [7; 25]. Next, the pathogen engages the substances and energy in the host's cells to promote its own proliferation, forming a greater number of spores, which are finally released into the intestine's lumen. The release of the spores can be connected with the cell burst of the infected intestine. At the same time, _N. ceranae_ inhibits host cell apoptosis to its own advantage, as this process is able to reduce the intensity of the infection [13; 26]. Furthermore, _N. ceranae_ infection negatively affects the intestine epithelium renewal rate and disrupts the signaling pathways responsible for maintaining homeostasis [27]. All these processes are the reason that microsporidian infection significantly increases the mortality of honeybee workers [7; 9; 10; 11; 12; 14; 17; 24; 26; 27]. _Nosema apis_ and _N. ceranae_ species were found to infect epithelial cells and clusters of regenerative cells in the honeybee midgut [24]. In this study, we indicated for the first time that the course of infection can lead to the formation of dead intestine cell spots, which can interrupt the host's intestinal continuity and cause severe damage to the host's intestine. This interruption of intestinal continuity is not connected with apoptotic changes, as nosemosis inhibits apoptosis [13], but is most probably associated with the necrosis of ventricular epithelial cells, as has been indicated in earlier studies [28]. This damage to the host's intestine during severe infection may explain why some studies report the presence of pathogenic DNA, not only in the intestine, where it multiplies, but also in other tissues, such as the hypopharyngeal glands, salivary glands, Malpighian tubules, and body fat [16; 29]. When spores enter the body cavity they can be transferred by the hemolymph, which flows freely inside the insect body and is in direct contact with organs and tissues. The presence of spores in glands and tissues can disturb their functions and increase the mortality rate of individual honeybees, as well as the whole honeybee colony. For example, the presence of spores in hypopharyngeal glands, which produce and secrete the components of royal jelly for brood and queen feeding, weakens the development and survival rate of the whole colony [29]. The presence of spores in the body fat [16], especially in winter bees that live from 4 to 9 months until spring, can heighten winter losses and reduce the chance of the infected honeybee colony surviving the winter. In conclusion, in \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Case**} & **Minimum** & **Maximum** & **Mean [\%]** & **SD [\%]** & **Variance** & **Skewness** & **Kurtosis** \\ \hline Healthy & 59.0 & 96.0 & 78.32 \({}^{\text{a}}\) & 6.37 & 40.52 & 0.10 & \(-0.11\) \\ \hline Infected & 26.0 & 56.0 & 41.05 \({}^{\text{b}}\) & 6.28 & 39.49 & \(-0.16\) & \(-0.58\) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Results of calculations and statistical analysis for the tested cases: healthy and infected honeybees.