ABSTRACT
Aims@#Several cockroach and ant species have been revealed to infest households with inadequate insect control and food storage practices. These household insects harbor countless bacteria species of public health, agricultural and industrial importance. Many studies have reported disease-causing bacteria from both cockroaches and ant’s species collected from hospitals and residential areas. The aim of this study was to characterize the culturable bacterial communities of two common household insects, big headed ants (Pheidole rugaticeps) and American cockroaches (Periplaneta americana) using 16S rRNA genes sequencing.@*Methodology and results@#A total of 64 bacterial sequences were obtained from P. rugaticeps (48.44%) and P. americana (51.56%) and Firmicutes was the most dominant phylum from both insect species. Bacillus was the most dominant bacterial genus from both cockroach and ant samples. Other important genera isolated were Pseudomonas and Stenotrophomonas which have previously been suggested to have members that are of biotechnological importance. Food poisoning bacterial species, B. cereus and other bacterial strains such as B. subtilis, Acinetobacter baumannii, Burkholderia cepacia, P. aeruginosa, Staphylococcus epidermidis, Serratia marcescens and S. pseudintermedius with the history of human infections were isolated from some of the insect’s specimens.@*Conclusion, significance and impact of study@#Thus, these household insect pests harbor bacterial species known to cause diseases of serious public health importance that needs serious attentions. Similarly, the insects harbor other bacteria species that may provide opportunities for biotechnological exploration.
Subject(s)
Ants , Periplaneta , Public HealthABSTRACT
Aims@#Wolbachia is an endosymbiont and a Gram-negative genus bacterium which has received the spotlight in the field of research studies due to its multiple capabilities to affect it hosts, including the bed bugs (Hemiptera: Cimcidae). While most investigations concentrated on the common bed bugs (Cimex lectularius), no published studies have yet to be done on molecular screenings of Wolbachia associated with tropical bed bugs (C. hemipterus). The present study was undertaken to screen Wolbachia infection from tropical bed bugs from Peninsular Malaysia. @*Methodology and results@#We attempted to screen and characterize Wolbachia infections in tropical bed bugs from 22 different localities throughout Peninsular Malaysia using a molecular approach; multiple Polymerase Chain Reaction (PCR) assays with four sets of primer sequences. @*Conclusion, significance and impact of study@#Our findings yielded negative results of Wolbachia infections and, therefore, further confirmed that all bed bug samples from all localities in Peninsular Malaysia are free from Wolbachia infections. Our findings also suggested that the prevalence of Wolbachia in tropical bed bug populations in Peninsular Malaysia is very unlikely.
ABSTRACT
Objective To test the effectiveness of conidial spore formulations [Aspergillus tubingensis (A. tubingensis) and Trichoderma harzianum (T. harzianum)] against tropical bed bugs, Cimex hemipterus. Methods Spore formulations were made from two fungal strains, T. harzianum and A. tubingensis. The bed bugs were exposed to the conidial spores placed soaked onto a fabric cloth for 1 h and the mortality counts were recorded daily until 14 days. Results Mean survival times based on Kaplan–Meier survival analysis showed no significant differences between all the concentrations in both the fungal isolates: T. harzianum and A. tubingensis. However, the evaluation of both the isolates in terms of virulence resulted in low lethal hours in all the concentrations except for the high concentration of A. tubingensis (LT
ABSTRACT
Objective: To investigate some morphological and molecular characteristics of fungal parasites isolated from wild tropical bed bug, Cimex hemipterus. Methods: A series of culture methods were used to obtain fungal isolates from field-collected bed bugs. Characteristics of the isolates such as colony appearance, mycelial texture and pigmentation were studied to explore their morphology. Isolates were also subjected to a PCR-based genotyping test. Results: There were noticeable differences in morphological characteristics among the four isolates. Conidial areas of one isolate were dark green, whereas those of the remaining colonies were olive-green, black or dark brown. Conidia of the dark green isolate were globose, while those of olive-green, black and dark brown isolates were globose to subglobose, globose to spherical and globose to subglobose/finely roughened, respectively. These morphological specificities and the molecular analyses showed that the fungal internal transcribed spacer ribosomal region and β-tubulin gene sequences of the isolates shared clade with Trichoderma and Aspergillus sequences. Conclusions: Overall, the new discovery of common pathogens in agricultural field developed in live bed bugs storage tank may initiate the use of biological agents in later years.