Distribution of commensal rodents in rain-fed and irrigated areas of Swat district, Khyber Pakhtunkhwa, Pakistan

Distribution pattern and relative abundance of the agricultural rodent pests of rain-fed and irrigated areas of district Swat Khyber Pakhtunkhwa, Pakistan were recorded from April 2011 to November 2013 using wire mesh live traps. A total of 350 rodents (269 Rattus rattus and 81 Mus musculus) were captured under 2268 trap nights (trap success: 0.15). Regression of daily captures on cumulative captures revealed an estimate of 350 rodents from all the sampled structures with an average of 21.8 rodents per crop field. House rats (R. rattus; 76.8% of captures) were numerically dominant in almost all types of agricultural fields, and were significantly different from the mice (Mus musculus; 23.1% of captures). Both species were found together in some fields. The sex ratio revealed that males outnumbered the females in both of the reported species.

Occurrence of Hymenolepis diminuta: a potential helminth of zoonotic importance in murid rodents

The study reveals the prevalence of a potential rodent-borne zoonotic helminth species, Hymenolepis diminuta in commensal rodents caught from irrigated and rain-fed areas of Swat, Pakistan. Three hundred and fifty rodents (269 rats and 81 mice) trapped during vegetative, flowering/fruiting and mature/harvesting stages of crops were studied from 2011-2013. Hymenolepisdiminuta eggs were identified on the basis of their shape, size, colour and markings on the surface of the egg shell and three pairs of embryonic hook-lets. Overall prevalence of H. diminuta was 3.14% (n=11/350). The highest prevalence 3.49% (n=5/143) of H. diminuta was noted at harvesting stages of the crops whereas the lowest 2.59% (n=2/77) during vegetative stage. Infection was higher in males 3.25% (n=7/215) than females 2.96% (n=4/135). Adult rodents were highly infected while no sub-adult was found infected. Infection was higher in mice 3.70% (3/81) than rats 2.69% (8/269) while no significance (p=1.0000:0.1250 to 32.00 CI). Rats and mice appears to show the most suitable reservoirs by hosting H. diminuta a zoonotic helminth. The presence of these rodents in all possible habitats can act as a main channel of transferring parasites through various habitats and can pose a hazard to humans in the area.

Distribution of commensal rodents in some shops of three districts in Malakand region, Pakistan

Using wire mesh live traps distribution pattern of the Rattus rattus and Mus musculus in different shops of three districts of Malakand region, Pakistan were recorded from September 2014 to October 2015. Over all 103 rodents (Rattus rattus 86 and Mus musculus 17) were caught during in 0.04 trap success (2448 trap nights). Regression of daily captures on cumulative captures revealed an estimate of 103 rodents from all the sampled structures with an average of 3.55 rodents per shop. R. rattus; 83.4% of captures were numerically dominant in almost all types of shops sampled, and were significantly different than Mus musculus; 16.5% of captures. Both species were found together in some shops while they were mostly trapped from the separate shops. Male rodents outnumbered the females.

Occurrence and Genetic Correlations of Yersinia spp. Isolated from Commensal Rodents in Northeastern Poland

Rodents can be a potential Yersinia spp. vector responsible for farm facilities contamination. The aim of the study was to determine the prevalence of Yersinia spp. in commensal rodents found in the farms and fodder factory areas to characterize the obtained isolates and epidemiological risk. Intestinal samples were subjected to bacteriological, bioserotype, and PCR examination for virulence markers ail, ystA, ystB, and inv presence. Yersinia spp. was isolated from 43 out of 244 (17.6%) rodents (Apodemus agrarius n = 132, Mus musculus n = 102, Apodemus sylvaticus n = 8, Rattus norvegicus n = 2). Y. enterocolitica was isolated from 41 rodents (16.8%), and from one Y. pseudotuberculosis and one Y. kristensenii. In three cases, two Y. enterocolitica isolates were obtained from one rodent. All Y. enetrocolitica contained ystB and belonged to biotype 1A, considered as potentially pathogenic. One isolate additionally had the ail gene typical for pathogenic strains. The sequence analysis of the ystB, ail, and inv fragments showed a high similarity to those from clinical cases. The current study revealed a high prevalence of Y. enetrocolitica among commensal rodents, but the classification of all of Y. enterocolitica isolates into biotype 1A and the sporadic isolation of Y. pseudotuberculosis do not indicate a high epidemiological risk.

Morphometric Study of Mus musculus, Rattus norvegicus, and Rattus rattus in Qatar

The current study was undertaken to estimate the morphometric pattern of three commensal rodents, i.e., Mus musculus, Rattus norvegicus, and Rattus rattus in Qatar. One hundred forty-eight rodents were captured from different facilities throughout Qatar. The captured rodents were used to identify the external body and cranio-mandibular morphometry. The study found that R. norvregicus was the most prevalent (n = 120, 81%, 95% CI: 73.83–87.05). Most of the rodents were collected from Al Rayan municipality (n = 92, 62%), were adults (n = 138, 93.2%, 95% CI: 87.92–96.71), and were from livestock farms (n = 79, 49%, 95% CI: 41.02–57.65). The rodents’ average body weights were 18.8 ± 2.2 gm, 264.3 ± 87.5 gm, and 130 ± 71.3 gm for M. musculus, R. norvegicus, and R. rattus, respectively. The research found that the studied rodents are smaller than those of other countries such as Turkey, Tunisia, and Iran. The study of morphometry is a useful tool for the traditional identification of small mammal species, including rodents. The average morphometric measurements of the external body and skull were normally distributed and can be used as a reference of R. norvegicus and R. rattus for Qatar. A further comprehensive study is required to investigate the rodent population index, eco-friendly control program, and public health importance in Qatar.

First record of 'tail-belting' in two species of free-ranging rodents (Apodemus flavicollis and Apodemus agrarius): Adaptation to prevent frostbite?

Rodents are among the most successful mammals because they have the ability to adapt to a broad range of environmental conditions. Here, we present the first record of a hitherto unknown thermal adaptation to low temperatures that repeatedly occurred in two species of non-commensal rodents (Apodemus flavicollis and Apodemus agrarius) between January 16 and February 11, 2021. The classic rodent literature implies that rodents prevent heat loss via a broad range of behavioral adaptations including sheltering, sitting on their tails, curling into a ball, or huddling with conspecifics. Yet, we have repeatedly observed an undescribed behavior which we refer to as tail-belting. The behavior was performed during the lowest temperatures, whereby animals - which were attracted out of their over-wintering burrows for a highly-palatable food reward - lift and curl the tail medially, before resting it on the dorsal, medial rump while feeding or resting between feeding bouts. We documented 115 instances of the tail-belting behavior; 38 in Apodemus agrarius, and 77 in Apodemus flavicollis. In A. flavicollis, this behavior was only observed below -6.9C, and occurred more often than in A. Agrarius. The latter only demonstrated the behavior below -9.5C. We further detail the environmental conditions under which the behavior is performed, and provide possible functions. We then set several directions for future research in this area.

Late Quaternary Environmental and Human Impacts on the Mitochondrial DNA Diversity of Four Commensal Rodents in Myanmar

We addressed the spatiotemporal characteristics of four commensal rodent species occurring in Myanmar in comparison with other areas of the Indo-Malayan region. We examined sequence variations of the mitochondrial cytochrome b gene (Cytb) in the Pacific rat (Rattus exulans), roof rat (Rattus rattus complex, RrC), lesser bandicoot rat (Bandicota bengalensis), and house mouse (Mus musculus) using the recently developed time-dependent evolutionary rates of mtDNA. The Cytb sequences of RrC from Myanmar were shown to belong to RrC Lineage II, and their level of genetic diversity was relatively high compared to those of the other three species. RrC was found to have experienced bottleneck and rapid expansion events at least twice in the late Pleistocene period in Myanmar and a nearby region. Accordingly, paleoclimatic environmental fluctuations were shown to be an important factor affecting rodents in the subtropics of the Indo-Malayan region. Our results show that human activities during the last 10,000 years of the Holocene period affected the population dynamics of the rodent species examined, including introducing them to Myanmar from neighboring countries. Further study of these four commensal rodents in other geographic areas of the Indo-Malayan region would allow us to better understand the factors that drove their evolution and their ecological trends.