-
Pathogens (Basel, Switzerland) Sep 2019Antimicrobial activities of phytochemicals--cinnamaldehyde (TC), ferulic acid (FA), -coumaric acid (-CA), caffeic acid (CA), chlorogenic acid (CHA), essential oil (TO),...
Antimicrobial activities of phytochemicals--cinnamaldehyde (TC), ferulic acid (FA), -coumaric acid (-CA), caffeic acid (CA), chlorogenic acid (CHA), essential oil (TO), essential oil (ECO), and oil (TTO) against species-were assessed. Growth of all subsp. and almost all strains was inhibited by TC at concentration 0.01 mg/mL, and for most strains minimal inhibitory concentrations (MIC) ranged from 0.01 to 0.19 mg/mL. The inhibitory effect of TC against subsp. was comparable to the effect of oxytetracycline, and in the case of subsp. and was higher compared to gentamicin. MIC of FA, -CA, and CA for most strains ranged from 1.56 to 3.12 mg/mL, and MIC values of TO for most strains ranged from 0.39 to 0.78 mg/mL. TO and TC at the concentrations below ½ MIC values used in mixtures exhibited strong synergism. ECO and TC showed synergy in mixture of ⅛ MIC of ECO and ¼ MIC of TC. TC and TO exhibited the strongest inhibitory and bactericidal effect against investigated species, and they are a promising alternative to the use of antibiotics in controlling the growth of these fish pathogens.
PubMed: 31500367
DOI: 10.3390/pathogens8030142 -
Journal of Wildlife Diseases Oct 2021The Lake Titicaca frog is endangered due to threats such as water pollution, introduced species, and overharversting for markets, where people consume them as frog...
The Lake Titicaca frog is endangered due to threats such as water pollution, introduced species, and overharversting for markets, where people consume them as frog juice. This study, conducted June to November 2012, aimed to determinate the bacteria microflora living on the skin of frogs confiscated from the La Parada market, Lima, Peru, and housed individually in the Laboratory of Wildlife at the Faculty of Veterinary Medicine and Zootechnic of the Universidad Peruana Cayetano Heredia in Lima, Peru. Samples collected with sterile swabs and cultured on blood, tryptic soy, and MacConkey agars were investigated using commercially available test kits, to investigate the commonly encountered bacterial and potentially zoonotic microorganisms associated with their consumption. We found three species of zoonotic concern in the genus Vibro: Vibrio alginolyticus, Vibro cholerae, and Vibro fluvialis. Other Gram-negative species cultured included two different colonies of Aeromonas hydrophila, or Aeromonas caviae or Aeromonas sobria; Pseudomona luteola; one example of Weeksella virosa or Empedobacter brevis; and Citrobacter freundii. Gram-positive bacteria detected were Staphylococcus spp., Micrococcus spp., and Erysipelothrix rhusiopathiae. We recommend against the consumption of this frog due to the pathogens it may carry that could cause serious illness among consumers and in vendors who handle animals.
Topics: Aeromonas hydrophila; Animals; Anura; Humans; Lakes; Peru; Staphylococcus
PubMed: 34424988
DOI: 10.7589/JWD-D-20-00076 -
Journal of Microbiological Methods Aug 2023Rapid and accurate detection of bacterial pathogens is critical in controlling disease outbreaks affecting farmed fish. The present study aimed to develop a novel...
Rapid and accurate detection of bacterial pathogens is critical in controlling disease outbreaks affecting farmed fish. The present study aimed to develop a novel serological diagnostic approach using nano‑silver based Enzyme-linked immunosorbent assay (ELISA) for speedy detection of Aeromonas veronii infections in Nile tilapia. A. veronii isolates used in ELISA assays were recovered from moribund Nile tilapia during a disease outbreak in a private fish farm in Egypt. A. veronii isolates were identified based on alignment analysis of the gyrB and 16S rRNA gene sequences. A. veronii antisera used in ELISA assays were prepared in tilapia, and the bacterial antigens were formalin-killed. The cut-off values were 0.46 and 0.48 in traditional and nano-based ELISA. There were no cross-reactions with bacterial isolates (Aeromonas hydrophila, Aeromonas caviae, Aeromonas sobria, Pseudomonas fluorescens, and Vibrio vulnificus). The lowest antigen concentration that produced positive results after checkerboard titration in indirect-ELISA (i-ELISA) and dot ELISA was 15 μg and 250 ng of prepared antigen, respectively. Nano-ELISA and nano-based dot-ELISA antigen concentration was 10 μg and 100 ng, respectively. Sera concentration was 1:100 in indirect-ELISA and dot-ELISA, while it was 1:50 in nano-based ELISA and nano dot-ELISA. The i-ELISA successfully detected anti-Aeromonas IgG antibodies with 83.33% sensitivity and 66.67% specificity, while in the dot-ELISA, the sensitivity and specificity were 83.33% and 100%, respectively. Nano dot-ELISA had 100% sensitivity, specificity, and accuracy. Nano dot-ELISA assays have higher specificity, sensitivity, and accuracy than traditional ELISAs in detecting A. veronii. Further studies are needed to develop a rapid test kit for on-site field diagnosis.
Topics: Animals; Aeromonas veronii; RNA, Ribosomal, 16S; Silver; Aeromonas hydrophila; Enzyme-Linked Immunosorbent Assay; Gram-Negative Bacterial Infections; Fish Diseases
PubMed: 37451347
DOI: 10.1016/j.mimet.2023.106782 -
MicrobiologyOpen Nov 2019Aeromonas is recognized as a human pathogen following ingestion of contaminated food and water. One major problem in Aeromonas identification is that certain species are...
Proteomic characterization and discrimination of Aeromonas species recovered from meat and water samples with a spotlight on the antimicrobial resistance of Aeromonas hydrophila.
Aeromonas is recognized as a human pathogen following ingestion of contaminated food and water. One major problem in Aeromonas identification is that certain species are phenotypically very similar. The antimicrobial resistance is another significant challenge worldwide. We therefore aimed to use mass spectrometry technology for identification and discrimination of Aeromonas species and to screen the antimicrobial resistance of Aeromonas hydrophila (A. hydrophila). A total of 150 chicken meat and water samples were cultured, and then, the isolates were identified biochemically by the Vitek 2 Compact system. Proteomic identification was performed by MALDI-TOF MS and confirmed by a microchannel fluidics electrophoresis assay. Principal component analysis (PCA) and single-peak analysis created by MALDI were also used to discriminate the Aeromonas species. The antimicrobial resistance of the A. hydrophila isolates was determined by Vitek 2 AST cards. In total, 43 samples were positive for Aeromonas and comprised 22 A. hydrophila, 12 Aeromonas caviae (A. caviae), and 9 Aeromonas sobria (A. sobria) isolates. Thirty-nine out of 43 (90.69%) Aeromonas isolates were identified by the Vitek 2 Compact system, whereas 100% of the Aeromonas isolates were correctly identified by MALDI-TOF MS with a score value ≥2.00. PCA successfully separated A. hydrophila, A. caviae and A. sobria isolates into two groups. Single-peak analysis revealed four discriminating peaks that separated A. hydrophila from A. caviae and A. sobria isolates. The resistance of A. hydrophila to antibiotics was 95.46% for ampicillin, 50% for cefotaxime, 45.45% for norfloxacin and pefloxacin, 36.36% for ceftazidime and ciprofloxacin, 31.81% for ofloxacin and 27.27% for nalidixic acid and tobramycin. In conclusion, chicken meat and water were tainted with Aeromonas spp., with a high occurrence of A. hydrophila. MALDI-TOF MS is a powerful technique for characterizing aeromonads at the genus and species levels. Future studies should investigate the resistance of A. hydrophila to various antimicrobial agents.
Topics: Aeromonas; Aeromonas caviae; Aeromonas hydrophila; Animals; Anti-Bacterial Agents; Bacterial Proteins; Bacterial Typing Techniques; Chickens; Drug Resistance, Bacterial; Humans; Meat; Microbial Sensitivity Tests; Proteome; Proteomics; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Water Microbiology
PubMed: 30614207
DOI: 10.1002/mbo3.782 -
Veterinary World Aug 2021The emergence of antibiotic-resistant bacterial pathogens has been increasingly reported, which has resulted in a decreasing ability to treat bacterial infections....
BACKGROUND AND AIM
The emergence of antibiotic-resistant bacterial pathogens has been increasingly reported, which has resulted in a decreasing ability to treat bacterial infections. Therefore, this study investigated the presence of spp., including its antibiotic resistance in various fish samples, spp., , and , obtained from Kelantan and Terengganu, Malaysia.
MATERIALS AND METHODS
In this study, 221 fish samples, of which 108 ( spp., n=38; , n=35; and , n=35) were from Kelantan and 113 ( spp., n=38; , n=35; and , n=40) were from Terengganu, were caught using cast nets. Then, samples from their kidneys were cultured on a Rimler Shott agar to isolate spp. Polymerase chain reaction (PCR) was used to confirm this isolation using specific gene primers for species identification. Subsequently, the isolates were tested for their sensitivity to 14 antibiotics using the Kirby-Bauer method, after which the PCR was conducted again to detect resistance genes: , -, , , , -, and .
RESULTS
From the results, 61 isolates were identified as being from the genus using PCR, of which 28 were , 19 were , seven were , and seven were . Moreover, 8, 12, and 8 of ; 4, 3, and 12 of ; 6, 0, and 1 of ; and 3, 3, and 1 of were obtained from spp., , and , respectively. In addition, the isolates showed the highest level of resistance to ampicillin (100%), followed by streptomycin (59.0%), each kanamycin and nalidixic acid (41.0%), neomycin (36.1%), tetracycline (19.7%), sulfamethoxazole (14.8%), and oxytetracycline (13.1%). Resistance to gentamicin and ciprofloxacin both had the same percentage (9.8%), whereas isolates showed the lowest resistance to norfloxacin (8.2%) and doxycycline (1.6%). Notably, all isolates were susceptible to chloramphenicol and nitrofurantoin. Results also revealed that the multiple antibiotic resistances index of the isolates ranged from 0.07 to 0.64, suggesting that the farmed fish in these areas were introduced to the logged antibiotics indiscriminately and constantly during their cultivation stages. Results also revealed that the gene was detected in 19.7% of the isolates, whereas the tetracycline resistance genes, and , were detected in 27.9% and 4.9% of the isolates, respectively. However, β-lactam resistance genes, and , were found in 44.3% and 13.1% of isolates, respectively, whereas and genes were found in 3.3% and 13.1% of the isolates, respectively.
CONCLUSION
This study, therefore, calls for continuous surveillance of antibiotic-resistant spp. in cultured freshwater fish to aid disease management and better understand their implications to public health.
PubMed: 34566322
DOI: 10.14202/vetworld.2021.2064-2072 -
Annals of Agricultural and... Jun 2023The aims of this study were to search for the presence of bacteria in sea snails () by using culturomics and Matrix-assisted laser desorption/ionization time-of-flight...
INTRODUCTION AND OBJECTIVE
The aims of this study were to search for the presence of bacteria in sea snails () by using culturomics and Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and the antibiotic resistance/susceptibility of the sea snails.
MATERIAL AND METHODS
The anti-microbial susceptibilities of Gram-negative bacteriawas assessed by the Kirby-Bauer disk diffusion method, the presence of the genes (mcr-1 to -5), the major carbapenemase and β-lactamase resistant genes in Gram-negative bacteria, using mPCR method and 16S rRNA sequence analysis of isolates.
RESULTS
Bacterial growth accounted for 100% and 94.2% in the samples of intestine and meat, respectively, in the snails. The main organisms identified by MALDI-TOF MS were subsp. salmonicida at 33.7%, followed by at 9.6% (10/104) and at 7.7% in meat and intestine samples. and are intrinsic or chromosomally-mediated resistant against ampicillin. No genes (-1 to -5), the major carbapenemase and β-lactamase resistant genes were found. subsp. showed very low levofloxacin and meropenem resistance levels at 2.9%. When the sequence was searched in the Blast database, the genome of isolate showed high similarity with the sequences.
CONCLUSIONS
Conclusions. The findings obtained not only provide data about the proportion of bacteria in the gut and meat of the sea snails and their antibiotic resistance/susceptibility, but also show the absence of carbapenemase, colistin, and β-lactamase resistant genes among bacterial isolates from sea snail gut microbes.
Topics: Animals; Anti-Bacterial Agents; RNA, Ribosomal, 16S; Drug Resistance, Bacterial; Anti-Infective Agents; Snails
PubMed: 37387372
DOI: 10.26444/aaem/163582 -
Animals : An Open Access Journal From... Feb 2023Plant extracts are a phytochemically-rich alternative to antibiotic and synthetic feed additives, with high systemic bioactivity in animals. The present study aimed to...
Plant extracts are a phytochemically-rich alternative to antibiotic and synthetic feed additives, with high systemic bioactivity in animals. The present study aimed to evaluate the effect of a hydroalcoholic extract of custard apple () leaf (ASLE) on the growth, hematobiochemical parameters, digestive enzyme activities, redox status, nonspecific immune response, and cold and bacterial infection tolerance in Nile tilapia (). A total of 300 Nile tilapia fingerlings (11.87 ± 0.48 g) were fed ASLE-supplemented diets at increasing levels of 0, 5, 10, 15, and 20 g/kg for 60 days. At the end of the feeding period, the fish were experimentally challenged with cold water stress or , and mortalities were recorded for 10 days. The results revealed that the growth performance and feed conversion ratio were significantly improved with an increasing level of ASLE supplementation. The hematologic profile and hepato-renal functions were retained within a healthy range in the various groups supplemented with an ASLE diet. Antioxidant status was significantly improved in the serum of fish fed ASLE-supplemented diets, in terms of superoxide dismutase (SOD), catalase (CAT) activities, reduced glutathione, and total antioxidant capacity. Meanwhile, the myeloperoxidase (MPO) and malondialdehyde (MDA) levels decreased significantly. Similarly, there was a noticeable improvement in the hepatic CAT and SOD activities and a reduction of hepatic MDA. Marked improvements in lysozyme activity, nitric oxide production, complement3 level, and phagocytic activity were recorded in groups fed ASLE-supplemented diets, which peaked with the 20 g ASLE/kg diet. Moreover, the serum glucose and cortisol levels significantly declined in groups fed ASLE at levels of 15-20 g/kg compared to the other groups. Supplementation with ASLE increased the activities of protease, lipase, and α-amylase. ASLE supplementation at a concentration of 10-20 g/kg diet enhanced the resistance of Nile tilapia to infection. According to this study, ASLE supplementation enhanced the antioxidant balance, non-specific immune response, physiological status, resistance against infection, and growth performance of Nile tilapia at supplementation levels of 10-20 g/kg diet.
PubMed: 36830534
DOI: 10.3390/ani13040746 -
Animals : An Open Access Journal From... Dec 2020In recent times, nutraceuticals have been used extensively to identify promising feed additives for the improvement of the aquaculture industry through the enhancement...
In recent times, nutraceuticals have been used extensively to identify promising feed additives for the improvement of the aquaculture industry through the enhancement of growth and survival rates, potentiation of the immune responses, and fortification of the resistance against infectious bacterial diseases. In this study, Nile tilapia () were fed with diets supplemented with quinoa seeds (QU) or prickly pear fruit peel (PP) at the dose levels of 10% or 20% of the diet. After 45 days of the feeding trial, the fish were exposed to challenge. The pre-challenge indices indicated that both supplements mediated a significant improvement in most of the estimated parameters, including survival rate, antioxidant status, hematological and immunological indices, and hepatoprotective potential. These effects were recorded in the groups fed with high doses of the supplements (20%). The least changes were observed in the QU-supplemented fish. In the spleen tissue, the gene was upregulated in the PP-, PP- and QU-supplemented groups, while the expression of the gene remained unaffected in all the supplemented groups, except for the PP-supplemented group, which showed an upregulation. After the challenge with , the relative survival percentage was improved by the supplementation of PP and QU, particularly in the PP-supplemented group, possibly via the promotion of immunological responses, hepatoprotective potency, and modulation of the studied genes. Moreover, the morphological structure of the tissues showed marked recovery. The findings suggest that Nile tilapia fed with different levels of PP peel and QU seeds, particularly at the level of 20%, enhanced the immune response in fish and improved their resistance against infection.
PubMed: 33271917
DOI: 10.3390/ani10122266 -
Acta Veterinaria Scandinavica Jan 2020Antimicrobial resistant bacteria are emerging biological contaminants of the environment. In aquatic ecosystems, they originate mainly from hospitals, livestock manure...
BACKGROUND
Antimicrobial resistant bacteria are emerging biological contaminants of the environment. In aquatic ecosystems, they originate mainly from hospitals, livestock manure and private households sewage water, which could contain antimicrobial agents and resistant microorganisms. Aeromonas spp. occur ubiquitously in aquatic environments and they cause disease in fish. Motile aeromonads are also associated with human gastrointestinal and wound infections and fish can act as a transmission route of antimicrobial resistance (AMR) aeromonads to humans. The environmental ubiquity, the natural susceptibility to antimicrobials and the zoonotic potential of Aeromonas spp. make them optimal candidates for studying the AMR in aquatic ecosystems.
RESULTS
The AMR patterns of 95 motile aeromonads isolated from freshwater fish during 2013 and 2016 were analyzed. All samples from fish came from farms and natural water bodies located in northern Italy, which is an area characterized by high anthropic impact on the environment. The isolates were biochemically identified as Aeromonas hydrophila, Aeromonas sobria or Aeromonas caviae and AMR was determined by the standard disk diffusion method. All isolates were resistant to cloxacillin, spiramycin and tilmicosin. High AMR frequencies (> 95%) were detected for tylosin, penicillin and sulfadiazine. AMR to danofloxacin, enrofloxacin, flumequine, ceftiofur, aminosidine, colistin, doxycycline, gentamicin, marbocyl and florfenicol was observed at low levels (< 10%). No AMR to cefquinome was found. Logistic regression showed several differences in antimicrobial activity between complexes. According to the source of aeromonads, only few differences in AMR between isolates from farmed and wild fish were observed.
CONCLUSIONS
Our data revealed an increasing trend of AMR to neomycin and apramycin among Aeromonas isolates during the study period, while resistance to erythromycin, tetracycline and thiamphenicol decreased. All isolates were multidrug resistance (MDR), but A. caviae showed the highest number of MDR per isolate. In most isolates, various degrees of MDR were detected to macrolides, quinolones, fluoroquinolones, polymyxins and cephalosporins (third and fourth generations), which are listed, by the World Health Organisation, to be among the highest priority and critically important antimicrobials in human medicine. Our findings underlined that freshwater fish can act as potential source of MDR motile aeromonads. Due to their zoonotic potential, this can pose serious threat to human health.
Topics: Aeromonas; Animals; Anti-Bacterial Agents; Drug Resistance, Bacterial; Fish Diseases; Fisheries; Fresh Water; Gram-Negative Bacterial Infections; Italy
PubMed: 31973764
DOI: 10.1186/s13028-020-0504-y -
Indian Journal of Medical Microbiology Jul 2021Aeromonas species can cause gastroenteritis, soft tissue infections, hepatobiliary tract and other infections. While most reported soft tissue infections have been...
Aeromonas species can cause gastroenteritis, soft tissue infections, hepatobiliary tract and other infections. While most reported soft tissue infections have been attributed to Aeromonas hydrophila, we report a case of necrotizing fasciitis caused by Aeromonas veronii biovar sobria. Prompt and accurate diagnosis cum treatment could help save children with Aeromonas soft tissue infections from developing a bacteremia with extended morbidity and mortality.
Topics: Aeromonas; Child; Cholangitis, Sclerosing; Fasciitis, Necrotizing; Gram-Negative Bacterial Infections; Humans; Infant, Newborn; Soft Tissue Infections
PubMed: 33810916
DOI: 10.1016/j.ijmmb.2021.03.012