Biology subjects

Heikinheimo, A.

Publications and source records attributed to Heikinheimo, A..

2 recordsLinked to original sources

bioRxiv2026

Heavy metal resistance promotes higher biomass formation in multidrug-resistant wastewater Escherichia coli isolates from Finland

Antimicrobial resistance alone is a serious threat to global public health, but even more so when multidrug-resistant bacteria harbour heavy metal resistance genes, as these can drive co-selection of antibiotics and produce biofilms. The presence of such genes, combined with the bacterias ability to form biofilms, is strongly linked to treatment failure, persistent infections, and reduced therapeutic options. Here, we used the resazurin-crystal violet combination assay to screen a representative cohort of whole-genome sequenced Escherichia coli isolates (n=20) obtained from wastewater surveillance. The specific biofilm formation (SBF) index was used to grade the intensity of biofilm formation as strong, moderate, weak, and non-biofilm producers. Correlation analysis was used to test the association between the intensity of biofilm formation and genotypic features. The SBF index revealed that most of the wastewater E. coli isolates (n=13/20) were weak/non-biofilm producers, four isolates produced moderate biofilms, and three isolates (ST1434: A-O18ab:H55; ST401:A-H25; and ST399:A-O19:H12) produced strong biofilms. The diversity of virulence factors was similar in most of the isolates, except for the three isolates, which had fewer abundant virulence factors. The correlation analysis showed that there was no association between the expression of virulence genes and the formation of strong biofilms by the isolates (p > 0.05). Drug resistance profile was not correlated with higher biofilm production (p > 0.05), as 68.8% (n=11/16) of multi-drug resistant (MDR) and 50% (n=2/4) of non-MDR isolates had weak or no biofilm formation. Similarly, the SBF index was not associated with the number of plasmids in each of the E. coli genomes (p = 0.334). However, there was a positive association between the presence of two or more heavy metal resistance genes (HMRGs) and the strong biofilm formation in our isolates (p = 0.002). Our findings revealed the low occurrence of strong biofilm producers among wastewater E. coli isolates. Further studies are needed to evaluate the impact of the presence of HMRGs and their direct or indirect contribution to enhancing biofilm production and persistence in environmental reservoirs.

microbiology↗

bioRxiv2020

Baseline epidemiology and associated dog ecology study towards stepwise elimination of rabies in Kwara state, Nigeria

Understanding domestic dog population dynamics and ecology is necessary for any effective rabies control program. This study was conducted as part of the baseline epidemiological studies necessary for the establishment of the Kwara Rabies Rapid Alert System "KRRAS". The aim of this study was to determine the dog population structure of Kwara State by assessing the dog ownership, vaccination status, and prevalence of dog bites. A total of 1,460 questionnaires were administered to respondents in the three senatorial zones of the state using Open Data Kit (ODK) between June 2019 to January 2020. Of the 1460 households surveyed, 293 (20.1%) owned at least one dog with an average of 2.25 dogs per household. The male to female ratio was 2.2:1 and 85% (n=250/293) of the owned dogs were local breeds. A total of 785 dogs was enumerated (659 dogs from 293 households and 126 free-roaming dogs) and 7811 persons which resulted in a dog-human ratio of 1:9.95. The estimated dog population is 376,789 (95% CI: 343,700 - 379,878). The dog anti-rabies vaccination coverage was 31% (n=92/293). The prevalence of dog-bite was 13% (n=193/1460) of which only 27% of the victims (n=61/225) received post-exposure prophylaxis (PEP). The ethnicity of respondents had a significant impact on dog ownership. Yorubas more often (OR: 2.2-5; 95% CI: 1.2 - 12.4; p < 0.001) owned dogs than other tribes. The vaccination status of owned dogs was greatly impacted by the level of education of the respondents (OR: 5.03; 95% CI: 1.5073 - 16.8324; p < 0.001); the breed of the dog with exotic dogs being more vaccinated (OR: 2.8; 95% CI: 0.7150 - 10.857; p < 0.001) and the confinement of the dog (OR: 2.07; 95% CI: 1.1592 - 3.7037; p < 0.001). Always confined dogs were twice more vaccinated than non-confined dogs. The results of the study showed that the vaccination coverage needs to be increased, the number of dog bites needs to be reduced, the number of non-confined dogs needs to be reduced and stray dog control strategies need to be implemented. The findings of this study showed very low vaccination coverage for dogs which is below the 70-80% target recommended for herd immunity by the world health organization.

microbiology↗