Bacterial biota associated with the invasive insect pest Tuta absoluta (Meyrick).

Tuta absoluta (the tomato pinworm) is an invasive insect pest with a highly damaging effect on tomatoes causing between 80 and 100% yield losses if left uncontrolled. Resistance to chemical pesticides have been reported in some T. absoluta populations. Insect microbiome plays an important role in the behavior, physiology, and survivability of their host. In a bid to explore and develop an alternative control method, the associated microbiome of this insect was studied. In this study, we unraveled the bacterial biota of T. absoluta larvae and adults by sequencing and analyzing the 16S rRNA V3-V4 gene regions using Illumina NovaSeq PE250. Out of 2,092,015 amplicon sequence variants (ASVs) recovered from 30 samples (15 larvae and 15 adults), 1,268,810 and 823,205 ASVs were obtained from the larvae and adults, respectively. A total of 433 bacterial genera were shared between the adults and larval samples while 264 and 139 genera were unique to the larvae and adults, respectively. Amplicon metagenomic analyses of the sequences showed the dominance of the phylum Proteobacteria in the adult samples while Firmicutes and Proteobacteria dominated in the larval samples. Linear discriminant analysis effect size (LEfSe) comparison revealed the genera Pseudomonas, Delftia and Ralstonia to be differentially enriched in the adult samples while Enterococcus, Enterobacter, Lactococcus, Klebsiella and Wiessella were differentially abundant in the larvae. The diversity indices showed that the bacterial communities were not different between the insect samples collected from different geographical regions. However, the bacterial communities significantly differed based on the sample type between larvae and adults. A co-occurrence network of significantly correlated taxa revealed a strong interaction between the microbial communities. The functional analysis of the microbiome using FAPROTAX showed that denitrification, arsenite oxidation, methylotrophy and methanotrophy as the active functional groups of the adult and larvae microbiomes. Our results have revealed the core taxonomic, functional, and interacting microbiota of T. absoluta and these indicate that the larvae and adults harbor a similar but transitory set of bacteria. The results provide a novel insight and a basis for exploring microbiome-based biocontrol strategy for this invasive insect pest as well as the ecological significance of some of the identified microbiota is discussed.

Vestibular disorders among adults in a tertiary hospital in Lagos, Nigeria.

Dizziness is not an uncommon complaint in the Otolaryngological clinics among other symptoms. To a large number of practitioners, the treatment of dizziness remains the same irrespective of the etiology, i.e., anti-vertiginous drugs. The objective of this study was to document the evaluation, causes and treatment of vestibular disorders among our patients. The design includes descriptive prospective study conducted in the Oto-rhino-laryngology and Orthopedic Clinics of Lagos University Teaching Hospital, Lagos and Nigerian Army Audiological Centre, 68 Nigerian Army Reference Hospital, Yaba, Lagos, Nigeria. Adult patients referred to the audiology clinic for dizziness had detailed history obtained by using structured questionnaire. General physical and neuro-otological examinations were done. Clinical diagnoses were made on standardized criteria. The patients had hearing evaluation, videonystagmography (VNG) evaluation using infrared videonystagmography system. X-ray of the cervical spine and computerized tomogram scan of internal auditory meatus and brain when indicated were done. A total of 102 patients were seen with age range between 21 and 90 years. Thirty patients (29.4%) recorded average duration of episode of vertiginous attacks in seconds, 69 (67.6%) recorded within minutes to hours and 3 (2.9%) with no definite pattern. Clinical signs on neuro-otological examination were elicited on 39 (38.2%) of the patients while on VNG the vestibular subtest mainly caloric test was abnormal unilaterally and bilaterally in 47 (46.1%) while with the oculomotor subtests, smooth pursuit tests were abnormal in 5 (6.9%), saccade tests were abnormal in 8 (7.8%) and OPK were abnormal in 9 (8.8%). Peripheral vestibular disorders are common of which benign paroxysmal positional vertigo (BPPV) was seen in 29 (28.4%), Meniere's disease in 22 (21.6%), recurrent vestibulopathy in 20 (19.6%), cervical vertigo in 18 (17.6%), psychogenic vertigo in 2 (2%), vestibular schwannoma, barotraumas and drug-induced vertigo in 1 (1%), respectively, central vestibular disorders of vascular origin 2 (2%), vertebrobasilar insufficiency in 1 (1%), post-traumatic vertigo in 3 (3%) and unknown in 2 (2%). In conclusion, peripheral vestibular disorders are common of which BPPV is the most prevalent. Pre-referral anti-vertiginous medication is common among general practitioners. The practising ORL/Head neck surgeon and orthopedic surgeons must be conversant with the tools of diagnosis, differential diagnosis and treatment.