scholarly journals Natural Antibiotic Susceptibilities ofEdwardsiella tarda, E. ictaluri, andE. hoshinae

2001 ◽  
Vol 45 (8) ◽  
pp. 2245-2255 ◽  
Author(s):  
Ingo Stock ◽  
Bernd Wiedemann

ABSTRACT The natural antibiotic susceptibilities to 71 antibiotics of 102Edwardsiella strains belonging to E. tarda (n = 42), E. ictaluri(n = 41), and E. hoshinae (n = 19) were investigated. MICs were determined using a microdilution procedure according to NCCLS criteria and German standards. All edwardsiellae were naturally sensitive to tetracyclines, aminoglycosides, most β-lactams, quinolones, antifolates, chloramphenicol, nitrofurantoin, and fosfomycin. Edwardsiella species were naturally resistant to macrolides, lincosamides, streptogramins, glycopeptides, rifampin, fusidic acid, and oxacillin. Although slight species-dependent differences in natural susceptibilities to some antibiotics (e.g., macrolides and cefaclor) were seen, differences in natural susceptibility affecting clinical assessment criteria were only seen with benzylpenicillin. Whereas E. tarda was naturally resistant to benzylpenicillin, E. hoshinae was naturally sensitive. Natural sensitivity and resistance to this penicillin were found among the strains of E. ictaluri.The observed oxacillin sensitivity of E. ictaluriwas attributed to the failure of the species to grow at higher salt concentrations found in oxacillin-containing microtiter plates. The present study describes a database concerning the natural susceptibility of Edwardsiella species to a wide range of antibiotics, which can be applied to validate forthcoming antibiotic susceptibility tests of these microorganisms.

2020 ◽  
Vol 13 (10) ◽  
pp. 2166-2171 ◽  
Author(s):  
Nurfarahin Ahmad Pauzi ◽  
Nurliyana Mohamad ◽  
Mohamad Azzam-Sayuti ◽  
Ina Salwany Md. Yasin ◽  
Mohd Zamri Saad ◽  
...  

Background and Aim: Aeromonas hydrophila is a major cause of bacterial infections affecting a wide range of warm water fishes worldwide. In Malaysia, A. hydrophila isolations from diseased fishes were previously reported; however, with limited information. The present study investigates the antibiotic susceptibility and pathogenicity of A. hydrophila isolated from farmed red hybrid tilapia (Oreochromis spp.) in Malaysia. Materials and Methods: A. hydrophila was biochemically identified and subjected to antibiotic susceptibility tests. The isolate was then intraperitoneally injected into red hybrid tilapia, and the mortality, clinicopathological changes, and LD50 were determined up to 240 h post-infection (hpi). Results: The isolate demonstrated multiple antibiotic resistances (MAR) toward amikacin, ampicillin, cefotaxime, amoxicillin, trimethoprim-sulfamethoxazole, erythromycin, and streptomycin, with a MAR index of 0.5. The experimental infection of A. hydrophila at 105 CFU/mL in the red hybrid tilapia resulted in 100% mortality at 240 hpi. The LD50 was determined at 1.1×104 CFU/mL. Infected fish demonstrated occasional erratic swimming patterns, localized hemorrhages and depigmentation on the body and operculum areas, fin erosion, enlargement of the gall bladder, and hemorrhage in internal organs. Microscopic observation of infected fish revealed brain congestion, tubular necrosis, and glomerular shrinkage in the kidneys, necrosis of hepatocytes, and congestion of blood vessels in the liver. Conclusion: The high virulence of A. hydrophila to the red hybrid tilapia emphasizes the importance of active, on-going monitoring of its prevalence in Malaysian tilapia farming.


2021 ◽  
Vol 12 ◽  
Author(s):  
Shahar Rotem ◽  
Ohad Shifman ◽  
Moshe Aftalion ◽  
David Gur ◽  
Tamar Aminov ◽  
...  

Rapid antibiotic susceptibility tests, performed directly on whole blood samples, will offer great clinical advantages. This issue is of considerable importance when it comes to bioterror pathogens where prompt antibiotic treatment should be offered to infected patients as well as prophylaxis to suspected exposed individuals. Herein, we describe a novel and rapid method, named MAPt, that is based on the direct application of a blood sample onto solid agar that has been embedded with different concentrations of the tested antibiotic. Following a short incubation, bacterial growth is monitored by qPCR. The method was applied on blood cultures and whole blood samples inoculated with the Tier-1 pathogens Bacillus anthracis, Yersinia pestis, and Francisella tularensis. The use of agar medium, which better supports the growth of bacteria at low concentrations, together with the use of qPCR, which provides sensitivity and specificity, allowed minimal inhibitory concentration (MIC) determination to a wide range of bacterial concentrations, ranging from ∼5 × 102 cfu/ml up to 108 cfu/ml. The omission of the enrichment procedure in blood culture and the isolation step, both required in standard antibiotic susceptibility tests (ASTs), allowed a dramatic reduction in time to answer, from a few days to a few hours. The total time required for MIC determination was ∼6 h for fast-growing bacteria, such as B. anthracis, and 12–16 h for slow-growing bacteria, represented by Y. pestis and F. tularensis. Accordingly, MAPt may offer health authorities means for public preparedness in the case of a bioterror attack as well as prompt clinical treatment options in common blood stream infections.


2002 ◽  
Vol 30 (4) ◽  
pp. 422-427 ◽  
Author(s):  
I Balci ◽  
F Ekşi ◽  
A Bayram

We aimed to determine the types of corynebacteria isolated from the blood of patients at Gaziantep University Hospital, Turkey, and their antibiotic susceptibilities. Between February 1999 and June 2001, 3530 blood samples were cultured, of which 915 were found to be positive, and these were further investigated in the bacteriology laboratory. Among positive blood cultures, coryneform bacteria were identified in 31 (3.4%) isolates. Of these, 16 (51.6%) were Corynebacterium jeikeium, six (19.4%) were Corynebacterium striatum, four (12.9%) were Corynebacterium amycolatum, two (6.5%) were Cellulomonas species, two (6.5%) were Corynebacterium afermentans and one isolate (3.2%) was Corynebacterium propinquum. Antibiotic susceptibility tests showed that C. jeikeium was resistant to various antibiotics, whereas all isolates were susceptible to vancomycin and teicoplanin. This study illustrates the importance of taking coryneform bacteria into consideration when culturing blood samples. The need to identify the species and determine its antibiotic sensitivity is emphasized.


2011 ◽  
Vol 1 (1) ◽  
pp. 31-35
Author(s):  
Deepak Dwivedi ◽  
Tejram Kushwah ◽  
Mukesh Kushwah ◽  
Vinod Singh

Antibiotics to treat dental caries infection are routinely prescribed which led to the increased resistance against bacteria. The purpose of this investigation was to perform antibiotic susceptibility tests on a panel of pathogenic bacteria isolated from dental caries infection. Bacteria were isolated from caries site of patients and identified at the species level. Each of 150 species of bacteria was tested for antibiotics susceptibility to a five antibiotics using Etest. The antibiotics used were Amoxicillin, Cloxocillin, Erythromycin, Tetracycline and Penicillin‐V. The obtained resistance percentage for each antibiotic were Penicillin V: 72/150 (48%), Tetracycline: 99/150 (66%), Amoxicillin: 135/150 (90%), Cloxocillin: 117/150 (78%), and Erythromycin: 90/150 (60%) (Table 1). In case of combinatorial antibiotic exposure, the resistance percentage of Penicillin V/Amoxicillin and Amoxicillin/ Erythromycin was 39/150 (26%), and 45/150 (30%) respectively. The study has well demonstrated the clinical picture of antibiotic resistance and susceptibility pattern of bacteria causing dental caries. The obtained comprehensive data will allow investigating the spatial distribution of pathogenic, antibiotic resistant bacteria among dental caries patients which further may help into development of novel diagnostic and treatment approaches for the same.


Author(s):  
Amina Ojochide Hassan ◽  
Innocent Okonkwo Ogbonna ◽  
Victor Ugochukwu Obisike

Microbial resistance to antibiotics and biofilm formation ability of food-borne pathogens are major global health challenges. Most milk and milk products (Madara and Nono) could be vehicles for the transmission of multidrug resistant genes among any community. This study was aimed at determining the antibiotic susceptibility patterns and biofilm forming ability of some food-borne pathogens isolated from common dairy products: Madara and Nono in Makurdi metropolis. Two hundred and forty (240) samples comprising of one hundred and twenty (120) each of Madara (fresh raw milk from cow “FRM”)) and Nono (chance fermented cow milk “CFM”) were examined for the presence of pathogens. Antibiogram of bacterial isolates (Staphylococcus aureus, Escherichia coli, Shigella spp., Salmonella spp. and Klebsiella spp.) using the disc diffusion method revealed that susceptibility for Ampicillin (86.9%), Streptomycin (83.9%) and Ciprofloxacin (75.0%). Resistance was shown (26.7%) to Nalidixic acid, a commonly used antibiotic reflecting a public health concern. Most resistant isolates had a multiple antibiotics index of 0.3 (27.54%) with a least multiple antibiotics resistance index of 0.6 (0.85%). Detection of biofilm formation of isolates was done by Tube method. The study also revealed that out the total of 236 isolates tested for biofilm formation, 67 (28.4%) isolates were non or weak biofilm producers, 77 (32.6%) isolates were moderate biofilm producers and 92 (39%) isolates were strong biofilm producers. Findings of this research show high presence of a wide range of microorganisms, particularly enteric pathogens and enterotoxigenic strains of S. aureus which portrayed multidrug resistance and biofilm formation suggesting that FRM (Madara) and CRM (Nono) products might be important sources of food-borne infections and intoxication.


2011 ◽  
Vol 5 (3) ◽  
pp. 56-65
Author(s):  
Samira Y. Yousif ◽  
Rasha Abid Ali Al-Khalidi

Total of 507 samples (clinical, environmental, food) were collected from different hospitals in Baghdad, water, soil, and different food stuffs. Biochemical and morphological characterization tests showed that seventeen isolates were identified as Aeromonas spp.These were farther characterized as Aeromonas hydrophila 10 isolates, Aeromonas sobria 2 isolates, Aeromonas eucrenophila 3 isolates, one isolate belongs to Aeromonas caviae and another one belongs to Aeromonas schubertii. Antibiotic susceptibility tests of all the isolates towards fifteen antibiotics agents were carried out and results showed that all isolates 100% were resistant to penicillin, ampicillin, ampiclox, 99% were resistant to lincomycin, 76.7% to cephalothin, 52.9% to cefotaxime. All isolates except one isolate of Aeromonas eucrenophila were sensitive to meropenem.


2019 ◽  
Vol 9 (2) ◽  
pp. 385-392
Author(s):  
A. S. Gur’ev ◽  
O. Yu. Shalatova ◽  
E. V. Rusanova ◽  
I. V. Vasilenko ◽  
A. Yu. Volkov

In this article data concerning coherent fluctuation nephelometry (CFN) use in clinical microbiology is presented. CFN-analyzer allows to solve two important problems – fast urine screening for bacteriuria within 2-4 hours and antibiotic susceptibility testing within 3-6 hours. Altogether more than 650 urine samples were tested, and the effectivity of CFN-analyzer for preliminary selection of samples for further analysis was shown. Method allows to detect negative samples, reducing the number of urine analyses by 70-80%. Simultaneous analysis of growth curves and concentration of microorganisms shows high sensitivity and specificity (95.2% и 96.9%). Also more than 250 antibiotic susceptibility tests were performed using CFN-analyzer to show its effectiveness for determination of resistant properties of both pure cultures and urine microflora without isolation of bacteria. The agreement with traditional methods was from 84% to 88%. The use of CFN-analyzer with express methods of identification of microorganisms (chromogenic nutrient broths or mass-spectrometry) allows to make full urine analysis within 1-2 days. In the future CFN-analyzer gives an opportunity to screen different human biological liquids, and finds an application for other microbiological tasks, including standardization and speeding-up in sanitary bacteriology.


2020 ◽  
Vol 11 (25) ◽  
pp. 6352-6361 ◽  
Author(s):  
Kaixiang Zhang ◽  
Shangshang Qin ◽  
Sixuan Wu ◽  
Yan Liang ◽  
Jinghong Li

Recent developments of microfluidics-based antibiotic susceptibility tests (ASTs) at the single-cell or single-molecule level are summarized for guiding antibiotic treatment.


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