Paenibacillus lautus, an opportunistic bacterial pathogen, isolated from Ixodes granulatus Supino (Acari: Ixodidae) collected from a Müller’s giant Sunda rat (Sundamys muelleri)

Abstract

Wild rodents are carriers of ectoparasites such as ticks that are vectors of infectious diseases with human and veterinary significances. Due to their close association with human dwellings, synanthropic wild rodents may aid the spread and transmission of tick-borne pathogens. In light of this, an effort was initiated to study the cultivable bacteria within ticks collected from wild rodents trapped in Sungai Congkak Recreational Forest, Selangor. Ticks collected from four different rodent species; Sundamys muelleri, Maxomys whiteheadi, Maxomys rajah and Rattus rattus, were sterilely homogenized and cultured. One unique bacterial isolate originating from an engorged adult female Ixodes granulatus Supino collected off a Sundamys muelleri rat was identified as Paenibacilus lautus via 16S rDNA, ctpA sequencing and biochemical tests. Antimicrobial susceptibility testing revealed that the P. lautus isolate was resistant to ampicillin, penicillin, clindamycin, chloramphenicol, rifampicin and trimethoprim-sulfamethoxazole, mirroring the antimicrobial susceptibility profiles of clinical strains. Recovery of this opportunistic bacterial pathogen from the tick suggests that it may be transmitted to humans or other hosts through tick bites and cause disease once it enters the bloodstream. Therefore, it is important to remain vigilant due to its pathogenic potential and improve our waste disposal practices to avoid attracting rodents.

Determination of Antibiotic and Heavy Metal Resistance in Paenibacillus lautus 51ATA

“…Ampicillin, Penicillin and Cephalexin resistance of P. lautus is previously reported, which is in line with our finding (Bhullar et al, 2012, Celandroni et al, 2016, Loong et al, 2018. On the other hand, some findings are contradictory to our results, as some isolates of P. lautus were resistant against Clindamycin, Chloramphenicol and Erythromycin, which our isolate was sensitive to (Bhullar et al, 2012, Loong et al, 2018. In addition, resistance against Daptomycin, Telithromycin, and Piperacillin is also reported (Bhullar et al, 2012).…”

Prevalence of on-host ticks (Acari: Ixodidae) in small mammals collected from forest near to human vicinity in Selangor, Malaysia

“…To date, there is still lack of information on the behaviour of this rodent species, especially its ranging and nesting patterns, although numerous studies have reported their wide distribution across Malaysia and the Southeast Asian region (Lynam & Billick 1999;Esselstyn et al 2004;Paramasvaran et al 2005;Charles & Ang 2010). Loong et al (2018) has successfully cultured an opportunistic bacterial pathogen (Paenibacillus lautus) from ticks collected from this species. These opportunistic bacteria may be transmitted to humans and other host through tick bites and cause disease.…”

Culturable pathogenic bacteria in ticks parasitizing farm animals and rodents in Malaysia

“…We employed a non-selective bacterial culture method in this study, previously shown to enable isolation of rare and pathogenic bacteria species from tick specimens such as Corynebacterium lactis (Lim et al, 2018) and P. lautus (Loong et al, 2018a). Even though no bacterial growth was observed for some tick specimens, we suggest that it was not due to the limitation of the agar culture media but the method employed for bacterial isolation (Stewart, 2012).…”

“…All ticks were stored in 70% ethanol prior to transportation to the laboratory for analyses. In the laboratory, collected ticks were surface sterilized with 70% ethanol and rinsed thoroughly with nuclease-free water to remove all possible environmental contaminants (Loong et al, 2018a). Adult ticks were then sorted according to species, host, sex and blood meal status into pools of between 1 and Table 2.…”

“…Amongst the bacterial species found within ticks, those in the genera of Rickettsia, Anaplasma, Coxiella and Ehrlichia that are commonly associated with human and animal infections (Khoo et al, 2016) are obligate intracellular pathogens incapable of growing on artificial nutrient culture. As disease transmission from ticks to humans occur through tick bites (Loong et al, 2018a), there is also risk of transmission of other pathogens carried within the ticks. To date, little is known on the prevalence of culturable pathogenic bacteria harbored within ticks.…”