scholarly journals Antibiotic resistant bacteria and commensal fungi are common and conserved in the mosquito microbiome

2019 ◽  
Author(s):  
Josephine Hyde ◽  
Courtney Gorham ◽  
Doug E. Brackney ◽  
Blaire Steven

AbstractThe emerging and increasing prevalence of bacterial antibiotic resistance is a significant public health challenge. To begin to tackle this problem, it will be critical to not only understand the origins of this resistance but also document environmental reservoirs of antibiotic resistance. In this study we investigated the possibility that both colony and field caught mosquitoes could harbor antibiotic resistant bacteria. Specifically, we characterized the antibiotic resistant bacterial populations from colony-reared Aedes aegypti larvae and adults and two field caught mosquito species Coquillettidia perturbans and Ochlerotatus canadensis. The cultured bacterial populations were dominated by isolates belonging to the class Gammaproteobacteria. Among the antibiotic resistant populations, we found bacteria resistant to carbenicillin, kanamycin, and tetracycline, including bacteria resistant to a cocktail of all three antibiotics in combination. The antibiotic resistant bacteria were numerically rare, at most 5% of total cell counts. Isolates were characterized by 16S rRNA gene sequencing, and clustering into Operational Taxonomic Units (OTUs; 99% sequence identity). 27 antibiotic resistant OTUs were identified, although members of an OTU did not always share the same resistance profile. This suggests the clustering was either not sensitive enough to distinguish different bacteria taxa or different antibiotic resistant sub-populations exist within an OTU. Finally, the antibiotic selection opened up a niche to culture mosquito-associated fungi, and 10 fungal OTUs (28S rRNA gene sequencing) were identified. Two fungal OTUs both classified to the class Microbotryomycetes were commonly identified in the field-caught mosquitoes. Thus, in this study we demonstrate that antibiotic resistant bacteria and certain fungi are common and conserved mosquito microbiome members. These observations highlight the potential of invertebrates to serve as vehicles for the spread of antibiotic resistance throughout the environment.

2020 ◽  
Author(s):  
Jawad Ali ◽  
Malik Owais Ullah Awan ◽  
Gulcin Akca ◽  
Iftikhar Zeb ◽  
Bilal AZ Amin ◽  
...  

AbstractAntibiotics discovery was a significant breakthrough in the field of therapeutic medicines, but the over (mis)use of such antibiotics (n parallel) caused the increasing number of resistant bacterial species at an ever-higher rate. This study was thus devised to assess the multi-drug resistant bacteria present in sanitation-related facilities in human workplaces. In this regard, samples were collected from different gender, location, and source-based facilities, and subsequent antibiotic sensitivity testing was performed on isolated bacterial strains. Four classes of the most commonly used antibiotics i.e., β-lactam, Aminoglycosides, Macrolides, and Sulphonamides, were evaluated against the isolated bacteria.The antibiotic resistance profile of different (70) bacterial strains showed that the antibiotic resistance-based clusters also followed the grouping based on their isolation sources, mainly the gender. Twenty-three bacterial strains were further selected for their 16s rRNA gene based molecular identification and for phylogenetic analysis to evaluate the taxonomic evolution of antibiotic resistant bacteria. Moreover, the bacterial resistance to Sulphonamides and beta lactam was observed to be the most and to Aminoglycosides and macrolides as the least. Plasmid curing was also performed for MDR bacterial strains, which significantly abolished the resistance potential of bacterial strains for different antibiotics. These curing results suggested that the antibiotic resistance determinants in these purified bacterial strains are present on respective plasmids. Altogether, the data suggested that the human workplaces are the hotspot for the prevalence of MDR bacteria and thus may serve the source of horizontal gene transfer and further transmission to other environments.


2021 ◽  
Vol 11 (3) ◽  
pp. 285-297
Author(s):  
Mohd Suhaimi ◽  
◽  
Kam Yern ◽  
Mohd Kamaroddin ◽  
Syahidatul Rizal ◽  
...  

The emergence of antibiotic resistant bacteria in aquatic environment has led to an increase in waterborne health risks to an alarming extent. This study attempts to investigate the population of certain antibiotic resistant strains in Peninsular Malaysia. From the samples of 14 rivers from 7 different states in Peninsular Malaysia, a total of 203 isolates were successfully isolated. These are from rivers in Negeri Sembilan, Melaka, Selangor, Kuala Lumpur, Kedah, Kelantan and Terengganu with 35, 15, 37, 39, 24, 26 and 27 isolates, respectively. The isolates were tested for their susceptibility towards 6 broad spectrum of antibiotics which are gentamicin, ampicillin, rifampicin, chloramphenicol, tetracycline, and ciprofloxacin. A total of 117 isolates were identified to have more than 20% MAR index value with 47 of the isolates possess minimum MAR index value of 50%. Based on MAR index value, 59% of isolates are high risk threats indicating a serious emergence of antibiotic resistant bacteria in the rivers in Peninsular Malaysia. Isolates with MAR index value of more than 50% were selected for 16S rRNA gene sequencing for further identification.Based on 16s rRNA gene sequencing, the isolates are a mixture of pathogenic and commensals bacteria. This also implies that the environment especially rivers can be a reservoir for genetic jugglery


2013 ◽  
Vol 67 (7) ◽  
pp. 1534-1543 ◽  
Author(s):  
Jesus Sigala ◽  
Adrian Unc

Standard protocols for monitoring wastewater treatment efficacy target Escherichia coli and fecal coliforms. This might not accurately describe risks associated with antibiotic resistance in the bacterial population of treated wastewaters. We modified a standard agar recovery method by amending it with various antibiotics. The resulting bacterial colonies were submitted to 454 pyrosequencing; thus we identified the diversity of culturable antibiotic resistant bacteria from treated and raw wastewaters. This approach produced 209,706 high quality reads of >300 bp. Operational taxonomic units (OTUs) within Proteobacteria dominated the system. The Shannon–Wiener H′ index showed bacterial populations recovered on ciprofloxacin amended agars to be the least diverse. Principal component analysis of OTU distribution at phylum level showed that Proteobacteria accounted for most of the variability. The same analysis revealed most of the samples to have similar diversities at phylum level being dominated by Proteobacteria, though a few samples, typically recovered from ciprofloxacin or doxycycline amended agars were often dissimilar. Arcobacter spp. or E. coli were dominant in the bacterial communities recovered on agars amended with ciprofloxacin or doxycycline, respectively. Genera containing putative pathogens were mostly representatives of Gamma and Epsilon proteobacteria. Bacterial populations containing multiple antibiotic resistance (MAR) in the final treated effluent was a possibility.


Antibiotics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 575
Author(s):  
Emi Nishimura ◽  
Masateru Nishiyama ◽  
Kei Nukazawa ◽  
Yoshihiro Suzuki

Information on the actual existence of antibiotic-resistant bacteria in rivers where sewage, urban wastewater, and livestock wastewater do not load is essential to prevent the spread of antibiotic-resistant bacteria in water environments. This study compared the antibiotic resistance profile of Escherichia coli upstream and downstream of human habitation. The survey was conducted in the summer, winter, and spring seasons. Resistance to one or more antibiotics at upstream and downstream sites was on average 18% and 20%, respectively, and no significant difference was observed between the survey sites. The resistance rates at the upstream site (total of 98 isolated strains) to each antibiotic were cefazolin 17%, tetracycline 12%, and ampicillin 8%, in descending order. Conversely, for the downstream site (total of 89 isolated strains), the rates were ampicillin 16%, cefazolin 16%, and tetracycline 1% in descending order. The resistance rate of tetracycline in the downstream site was significantly lower than that of the upstream site. Furthermore, phylogenetic analysis revealed that many strains showed different resistance profiles even in the same cluster of the Pulsed-Field Gel Electrophoresis (PFGE) pattern. Moreover, the resistance profiles differed in the same cluster of the upstream and the downstream sites. In flowing from the upstream to the downstream site, it is plausible that E. coli transmitted or lacked the antibiotic resistance gene.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1841
Author(s):  
Thanaporn Chuen-Im ◽  
Korapan Sawetsuwannakun ◽  
Pimmnapar Neesanant ◽  
Nakarin Kitkumthorn

Antibiotic resistance of microorganisms is a serious health problem for both humans and animals. Infection of these bacteria may result in therapy failure, leading to high mortality rates. During an early intervention program process, the Sea Turtle Conservation Center of Thailand (STCCT) has faced high mortality rates due to bacterial infection. Previously, investigation of juvenile turtle carcasses found etiological agents in tissue lesions. Further determination of sea water in the turtle holding tanks revealed a prevalence of these causative agents in water samples, implying association of bacterial isolates in rearing water and infection in captive turtles. In this study, we examined the antibiotic resistance of bacteria in seawater from the turtle holding tank for a management plan of juvenile turtles with bacterial infection. The examination was carried out in three periods: 2015 to 2016, 2018, and 2019. The highest isolate numbers were resistant to beta-lactam, whilst low aminoglycoside resistance rates were observed. No gentamicin-resistant isolate was detected. Seventy-nine isolates (71.17%) were resistant to at least one antibiotic. Consideration of resistant bacterial and antibiotic numbers over three sampling periods indicated increased risk of antibiotic-resistant bacteria to sea turtle health. Essentially, this study emphasizes the importance of antibiotic-resistant bacterial assessment in rearing seawater for sea turtle husbandry.


Author(s):  
O. Aleruchi ◽  
O. Obire

This investigation focuses on molecular identification of antibiotic resistant bacteria isolated from petroleum producing vicinity using 16S rRNA sequencing based technique. The bacterial 16s rRNA gene sequences were amplified using polymerase chain reaction, sequenced,  characterized and compared by using primers which has been compared to national center for biotechnology information (NCBI) sequence database. The presence of the plasmid mediated antibiotic resistance determinants CTX-M and QNRB genes in the bacterial isolates were analyzed. A total of four bacterial isolates that were resistant to all the antibiotic agents used were identified molecularly. The BLAST results showed 100 % similarity and phylogenetic study indicated that the genes were evolutionarily related to Morganella morganii, Pseudomonas xiamenensis, Chryseobacterium cucumeris and Staphylococcus sp., respectively. The genes obtained were submitted to the NCBI gene bank and were assigned accession number; MN094330, MN094331, MN094332 and MN094333, respectively. CTX-M and QNRB genes were however absent in the bacterial isolates. The result identified some peculiar abilities of the bacterial isolates to be resistant to antibiotics and suggests a correlation with resistance and hydrocarbon utilizing bacteria. The level of resistance could be as a result of the disinfection process during wastewater treatment procedure or the same adaptive mechanisms possessed by the isolates to control the hydrocarbon concentration in their cell. The study also clearly indicates that these wastewaters, when discharged into the environment directly may pose a risk for the spread of antibiotic resistant bacteria.


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