# Influence of _Eisenia fetida_ on the Nematode Populations during Vermicomposting Process
## 3 Results and Discussion
Figure 3: _Cont._  
_Acrostichus_ is a genus with species inhabiting various habitats. They have been found to inhabit soil [38,39] dead wood [40] leafs, dung, and polluted water. Most species are bacteriophages but may also feed on protozoa, fungi, and nematodes [41]. Our data are inline with previously published. Unexpectedly, the analyzed compost samples detected the presence of sequences reads of _Acrostichus floridensis_, which occurrence previously had been reported only in Florida [42]. BLASTn analysis of the randomly selected 100 OTU assigned to this species showed that most of them had 100% identity with reference sequences from the GenBank database. This suggests that the range of this species is most likely much wider. Panagrolaimidae can live in extreme conditions, including desiccation [43,44] freezing [45] and an unusual range of pH conditions [46]. Introduction into the compost _E. fetida_ led to a noticeable reduction in _H. gingivalis_ and _H._ cf. _gingivalis_, which also belongs to the Panagrolaimidae family (Figure 3). This species has been described as saprophyic bacteriovorous [47], which was detected in potting soil in Germany, in vegetable compost pile in the USA [48], in soil samples from the paddocks and meadows surrounding the stables and manure heap in Belgium [49] and in compost in Belgium [50]. It is referred to as a facultative parasite which infects horses [51, 52, 53, 54], zebras (_Equus greryn_) [55], humans [56,57] and some other species [52], causing granulomatous and neurological lesions. It has been detected worldwide but the majority of the reports in humans and equids so far come in Europe, North America and North East Asia [52]. Several routes of infection have been described, including the oral route via the ingestion of contaminated plant material [53], the respiratory route via inhalation of nematodes [52], and cutaneous infection [58]. Although _H. gingivalis_ is a facultative parasite, infection from it is usually fatal. So far, treatment has been reported to be successful in only a few cases [47,58]. Moreover, it is tolerant to commonly use anthelmintic drugs, which does not allow us to expect better results of the therapy [49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59]. Halicephalobiosis, considered rare, can be a fatal disease that can result in mortality and morbidity in horses and humans, respectively. Our data align with those previously obtained [47,50], offering quantitative insights into the abundance and its alterations throughout the maturation of compost. Based on our experience, the incorporation of _E. fetida_ leads to a decrease in _H. gingivalis_ in all compost variants below 0.1% (Figure 4). Figure 3: The nematode density per 200 cc compost sample at the level of five trophic group: bacterioves, fungivores, plant-parasitic nematodes (PPN), omnivores and predators in three compost variants without earthworms: C1 (**A**), C2 (**B**), C3 (**C**), and three compost variants with _Eisenia fetida_: C4 (**D**),C5 (**E**), C6 (**F**) during the fourth data collection period (Pi- on the initial day of composting, Pf1- on the 30 th day of composting, Pf2- on the 60 th day of composting, and Pf3- on the 90 th day of composting) (n = 3). The presence of E. _fetida_ in the compost significantly increased abundance of Diplogasteridae. In the compost without _E. ftida_, the amount of Diplodasteridae exceeds 0.1% only after the 30 th (C3) or the 60 th (C1, C2) day of composoting, while in the compost with _E.fetida_ they are present in large amounts (11.0-28.0%) already on the 30 th day of composoting (Figure 5).