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Microbiology Spectrum Aug 2023mosquitoes are the primary vectors for the transmission of malaria parasites, which poses a devastating burden on global public health and welfare. The recent invasion...
mosquitoes are the primary vectors for the transmission of malaria parasites, which poses a devastating burden on global public health and welfare. The recent invasion of Anopheles stephensi in Africa has made malaria eradication more challenging due to its outdoor biting behavior and widespread resistance to insecticides. To address this issue, we developed a new approach for mosquito larvae control using gut microbiota-mediated RNA interference (RNAi). We engineered a mosquito symbiotic gut bacterium, Serratia fonticola, by deleting its gene to produce double-stranded RNAs (dsRNAs) in the mosquito larval gut. We found that the engineered strains can stably colonize mosquito larval guts and produce dsRNAs ds or ds to activate RNAi and effectively suppress the expression of methoprene-tolerant gene and ecdysone receptor gene , which encode receptors for juvenile hormone and ecdysone pathways in mosquitoes, respectively. Importantly, the engineered strains markedly inhibit the development of A. stephensi larvae and leads to a high mortality, providing an effective dsRNA delivery system for silencing genes in insects and a novel RNAi-mediated pest control strategy. Collectively, our symbiont-mediated RNAi (smRNAi) approach offers an innovative and sustainable method for controlling mosquito larvae and provides a promising strategy for combating malaria. Mosquitoes are vectors for various diseases, imposing a significant threat to public health globally. The recent invasion of A. stephensi in Africa has made malaria eradication more challenging due to its outdoor biting behavior and widespread resistance to insecticides. RNA interference (RNAi) is a promising approach that uses dsRNA to silence specific genes in pests. This study presents the use of a gut symbiotic bacterium, Serratia fonticola, as an efficient delivery system of dsRNA for RNAi-mediated pest control. The knockout of , a dsRNA-specific endonuclease gene, in using CRISPR-Cas9 led to efficient dsRNA production. Engineered strains of can colonize the mosquito larval gut and effectively suppress the expression of two critical genes, and , which inhibit mosquito development and cause high mortality in mosquito larvae. This study highlights the potential of exploring the mosquito microbiota as a source of dsRNA for RNAi-based pest control.
Topics: Animals; RNA Interference; Anopheles; Larva; Insecticides; Ribonuclease III; Mosquito Vectors; RNA, Double-Stranded; Malaria
PubMed: 37458601
DOI: 10.1128/spectrum.01666-23 -
World Journal of Clinical Cases Oct 2022Diagnosis of emphysematous pyelonephritis has been described around the world for some decades, frequently associated with and other anaerobic, gas-forming bacteria and...
BACKGROUND
Diagnosis of emphysematous pyelonephritis has been described around the world for some decades, frequently associated with and other anaerobic, gas-forming bacteria and mostly in patients living with diabetes. We present a case report of emphysematous pyelonephritis in a non-diabetic patient caused by as well as a brief literature review to draw attention to this rare pathogen as a cause of pyelonephritis.
CASE SUMMARY
A 38-year-old female presented with fever, severe pain in the right flank and changes in urinary habits. She was admitted, and emphysematous pyelonephritis was confirmed by an abdominal computerized tomography and urine cultures; the latter showed as a single pathogen. After 3 d of being treated with piperacillin/tazobactam and percutaneous drainage she became afebrile, and the gas presence reduced.
CONCLUSION
Emphysematous pyelonephritis infections in non-diabetic patients are rare but can be severe and life-threatening. This case suggests that infection can occur in patients undergoing invasive or instrumented procedures.
PubMed: 36312511
DOI: 10.12998/wjcc.v10.i29.10600 -
Acta Biochimica Polonica Aug 2021Despite the fact that cephalosporins are rarely used in medical or veterinary treatment, the presence of Enterobacterales strains resistant to this group of...
Despite the fact that cephalosporins are rarely used in medical or veterinary treatment, the presence of Enterobacterales strains resistant to this group of anti-bacterial drugs (ESBL) is an important issue that requires attention. Between 2019 and 2021, 14 retention reservoirs, 12 streams, 3 rivers and 1 lake situated in the Tricity area (in northern Poland) were sampled for the presence of ESBL strains. Out of 40 water samples, characteristic growth (E. coli and the KESC group) on Chromagar ESBL plates was observed for 33 samples. The average number of ESBL E. coli was 42±132 CFU/100 ml, while the KESC group was 73±147 CFU/100 ml. Out of 33 positive samples, 57 ESBL Enterobacterales strains were isolated, of which the most abundant species were E. coli (13 isolates) and S. fonticola (23 isolates). The E. coli ESBL isolates not only showed resistance to third generation cephalosporins but also to antibiotics from other groups, such as fluoroquinolones, aminoglycosides and sulfonamides. The S. fonticola ESBL isolates were also found to be mainly resistant to the third generation cephalosporins, with the exception of 5 imipenem and 2 ertapenem-resistant strains. These strains presented highly diverse fingerprinting profiles, as well as significant differences in phenotypic traits helpful for survival in the environment, such as biofilm formation and motility. Moreover, biofilm formation and the swimming ability were species and temperature dependent. We confirmed the presence of highly diverse ESBL strains with multiple drug resistance patterns in the Tricity water reservoirs. This could possibly pose a threat to human health and create a suitable ground for acquiring antibiotics resistance in the natural environment.
Topics: Anti-Bacterial Agents; Biofilms; Cephalosporins; Drug Resistance, Multiple, Bacterial; Environmental Microbiology; Escherichia coli; Humans; Microbial Sensitivity Tests; Poland; Rivers; Serratia; Water Microbiology; Water Supply; beta-Lactamases
PubMed: 34428264
DOI: 10.18388/abp.2020_5740 -
Microorganisms Jun 2022Histamine is a toxic biogenic amine commonly found in seafood products or their derivatives. This metabolite is produced by histamine-producing bacteria (HPB) such as ,... (Review)
Review
Histamine is a toxic biogenic amine commonly found in seafood products or their derivatives. This metabolite is produced by histamine-producing bacteria (HPB) such as , , , , , , , , spp., , , , , , , , , , spp., , , , , , and In this review, the role of these bacteria in histamine production in fish and seafood products with consequences for human food poisoning following consumption are discussed. In addition, methods to control their activity in countering histamine production are proposed.
PubMed: 35744715
DOI: 10.3390/microorganisms10061197 -
AMB Express Nov 2020Salmonella spp. is a high-risk bacterial pathogen that is monitored in imported animal-derived feedstuffs. Serratia fonticola is the bacterial species most frequently...
Salmonella spp. is a high-risk bacterial pathogen that is monitored in imported animal-derived feedstuffs. Serratia fonticola is the bacterial species most frequently confused with Salmonella spp. in traditional identification methods based on biochemical characteristics, which are time-consuming and labor-intensive, and thus unsuitable for daily inspection and quarantine work. In this study, we established a duplex real-time qPCR method with invA- and gyrB-specific primers and probes corresponding to Salmonella spp. and S. fonticola. The method could simultaneously detect both pathogens in imported feedstuffs, with a minimum limit of detection for Salmonella spp. and S. fonticola of 197 copies/μL and 145 copies/μL, respectively (correlation coefficient R = 0.999 in both cases). The amplification efficiency for Salmonella spp. and S. fonticola was 98.346% and 96.49%, respectively. Detection of fishmeal was consistent with method GB/T 13091-2018, and all seven artificially contaminated imported feed samples were positively identified. Thus, the developed duplex real-time qPCR assay displays high specificity and sensitivity, and can be used for the rapid and accurate detection of genomic DNA from Salmonella spp. and S. fonticola within hours. This represents a significant improvement in the efficiency of detection of both pathogens in imported feedstuffs.
PubMed: 33236244
DOI: 10.1186/s13568-020-01144-x -
Foods (Basel, Switzerland) Oct 2021Fresh vegetables are an essential part of a healthy diet, but microbial contamination of fruits and vegetables is a serious concern to human health, not only for the...
Fresh vegetables are an essential part of a healthy diet, but microbial contamination of fruits and vegetables is a serious concern to human health, not only for the presence of foodborne pathogens but because they can be a vehicle for the transmission of antibiotic-resistant bacteria. This work aimed to investigate the importance of fresh produce in the transmission of extended-spectrum β-lactamases (ESBL)-producing . A total of 174 samples of vegetables (117) and farm environment (57) were analysed to determine enterobacterial contamination and presence of ESBL-producing . Enterobacterial counts above the detection limit were found in 82.9% vegetable samples and 36.8% environmental samples. The average count was 4.2 log cfu/g or mL, with a maximum value of 6.2 log cfu/g in a parsley sample. Leafy vegetables showed statistically significant higher mean counts than other vegetables. A total of 15 ESBL-producing isolates were obtained from vegetables (14) and water (1) samples and were identified as (11) and (4). Five isolates of were considered multi-drug resistant. Even though their implication in human infections is rare, they can become an environmental reservoir of antibiotic-resistance genes that can be further disseminated along the food chain.
PubMed: 34828891
DOI: 10.3390/foods10112609 -
Molecules (Basel, Switzerland) Jun 2022The prevalence of cephalosporine-resistant (3GC-R) strains among United States community-related research samples ranged from 5.6 to 10.8%, while, in the European...
The prevalence of cephalosporine-resistant (3GC-R) strains among United States community-related research samples ranged from 5.6 to 10.8%, while, in the European countries, it was 1.2% to 10.1%. Several studies suggest that meat of animal origin could be one of the reservoirs of 3GC-R bacteria. Here, 86 raw meat samples (turkey, pork, chicken and beef) were collected randomly and verified for the presence of 3GC-R bacteria. The 3GC-R bacteria were isolated, identified and characterized phenotypically (antibiotic resistance, motility and biofilm) and genotypically (repetitive-sequence-based rep-PCR) to elucidate any correlations with principal component analysis (PCA). From 28 3GC-R positive samples, 41 strains were isolated, from which the majority belonged to (39%), followed by (19.5%), (17.1%) and (14.6%). The isolates of and presented diverse profiles in rep-PCR. Generally, 3GC-R strains were more resistant to antibiotics used in veterinary medicine than in human medicine. PCA derived from antibiotic resistance, motility and biofilm formation of and strains showed that resistance to beta-lactams was separated from the resistance to other antibiotic classes. Moreover, for the , and , the type of meat can create a specific tendency towards antibiotic resistance and phenotypic characteristics for , while these relationships were not found for other tested species.
Topics: Animals; Anti-Bacterial Agents; Cattle; Cephalosporins; Drug Resistance, Multiple, Bacterial; Escherichia coli; Humans; Meat; beta-Lactamases
PubMed: 35807396
DOI: 10.3390/molecules27134151 -
IDCases 2016Serratia fonticola is an unusual human pathogen, previously described primarily as causing skin and soft tissue infections following trauma. There is little information...
Serratia fonticola is an unusual human pathogen, previously described primarily as causing skin and soft tissue infections following trauma. There is little information in the literature about its treatment or susceptibilities. We describe the case of a 67-year-old male with paraplegia who developed urosepsis due to S. fonticola. Blood and urine cultures obtained prior to the initiation of antimicrobials both grew S. fonticola. The patient completed a 15-day course of antimicrobials and had an uneventful recovery. We reviewed 17 other patients with clinical cultures positive for S. fonticola. Of these, 11 isolates were from the genitourinary system, most often as part of a polymicrobial culture. The majority of the other organisms recovered were recognized pathogens from the Enterobacteriaceae family. The cases suggest that when recovered in conjunction with other organisms, S. fonticola does not lead to enhanced virulence or worse clinical outcomes and may be a bystander. When detected alone, which is a rare occurrence, S. fonticola may function as a human pathogen.
PubMed: 27347484
DOI: 10.1016/j.idcr.2016.05.003 -
Scientific Reports Nov 2020The use of microorganisms that allows the recovery of critical high-tech elements such as gallium (Ga) and indium (In) has been considered an excellent eco-strategy. In...
The use of microorganisms that allows the recovery of critical high-tech elements such as gallium (Ga) and indium (In) has been considered an excellent eco-strategy. In this perspective, it is relevant to understand the strategies of Ga and In resistant strains to cope with these critical metals. This study aimed to explore the effect of these metals on two Ga/In resistant strains and to scrutinize the biological processes behind the oxidative stress in response to exposure to these critical metals. Two strains of Serratia fonticola, A3242 and B2A1Ga1, with high resistance to Ga and In, were submitted to metal stress and their protein profiles showed an overexpressed Superoxide Dismutase (SOD) in presence of In. Results of inhibitor-protein native gel incubations identified the overexpressed enzyme as a Fe-SOD. Both strains exhibited a huge increase of oxidative stress when exposed to indium, visible by an extreme high amount of reactive oxygen species (ROS) production. The toxicity induced by indium triggered biological mechanisms of stress control namely, the decrease in reduced glutathione/total glutathione levels and an increase in the SOD activity. The effect of gallium in cells was not so boisterous, visible only by the decrease of reduced glutathione levels. Analysis of the cellular metabolic viability revealed that each strain was affected differently by the critical metals, which could be related to the distinct metal uptakes. Strain A3242 accumulated more Ga and In in comparison to strain B2A1Ga1, and showed lower metabolic activity. Understanding the biological response of the two metal resistant strains of S. fonticola to stress induced by Ga and In will tackle the current gap of information related with bacteria-critical metals interactions.
Topics: Bacterial Proteins; Electronics; Environmental Pollutants; Gallium; Humans; Indium; Microbial Sensitivity Tests; Oxidative Stress; Reactive Oxygen Species; Serratia; Superoxide Dismutase
PubMed: 33230153
DOI: 10.1038/s41598-020-77447-7 -
Japanese Journal of Infectious Diseases Jan 2021Five novel strains of Serratia fonticola that produce FONA, a minor extended-spectrum beta-lactamase (ESBL), were isolated during routine surveillance of ESBL-producing...
Five novel strains of Serratia fonticola that produce FONA, a minor extended-spectrum beta-lactamase (ESBL), were isolated during routine surveillance of ESBL-producing Enterobacteriaceae in imported chicken meat in Japan in 2017 and 2018. These strains exhibited a clear ESBL phenotype in susceptibility tests carried out in the presence of clavulanic acid; however, all strains tested negative in a multiplex polymerase chain reaction assay used to detect TEM, SHV, and CTX-M β-lactamase genes. After identification of the bacterial species as S. fonticola, full length bla genes were amplified and the DNA sequences were determined. The bla genes from all 5 strains were different from those previously reported (bla to bla); they clustered close to one another but were distinct from previously reported bla genes in a phylogenic analysis based on amino acid sequences.
Topics: Animals; Bacterial Proteins; Chickens; Enterobacteriaceae; Enterobacteriaceae Infections; Food Contamination; Food Microbiology; Humans; Japan; Meat; Microbial Sensitivity Tests; Serratia; beta-Lactamases
PubMed: 32741928
DOI: 10.7883/yoken.JJID.2020.114