species (spp) are the most prevalent zoonotic pathogens that cause outbreaks of gastroenteritis worldwide. Therefore evaluation of the profile of antibiotic resistance, virulence factors, and plasmid ...replicon types in these bacteria is necessary to control and prevent the spread of potentially pathogenic and drug-resistant strains.
This study was performed on 39
spp. The antibacterial susceptibility of isolates to various antibiotic agents was determined using disk diffusion test. β-lactamases (
) including ESBLs, AmpC, MBLs, and virulence genes were detected by PCR methods. Plasmid incompatibility groups among the isolates were identified using PCR-based replicon typing (PBRT).
The most prevalent virulent gene was
(84.6%).
, and
were identified in 79.4% (n=31), 69.2% (n=27), and 2.5% (n=1) of the isolates, respectively. The antibiotic susceptibility testing showed that 30.7% of the isolates were ESBL-producing.
(41%; n=16) was the most frequent β-lactamase gene among the isolates followed by
(15.4%; n=6),
(7.7%; n=3), and
(1.5%; n=1). Six different plasmid replicon types, including IncP (n=9; 23%), IncFIC (n=3; 7.70%), IncY (n=3; 7.70%), IncI1-Iγ (n=2; 5.12%), IncFIIAs (n=1; 2.56%), and IncN (n=1; 2.56%) were observed among the isolates.
Our study showed the emergence of carbapenem-resistant and
among
spp. for the first time in Kerman, Iran. Since
spp. plays an important role in the transmission of resistance genes in livestock and humans in the food chains, so more stringent control policies are recommended to prevent the circulation of drug-resistant and potentially pathogenic strains from animals to humans.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Background
Escherichia coli
(
E. coli
) serves as a common indicator of gut microbiota and is utilized for monitoring antimicrobial resistance determinants in food-producing animals. This study aimed ...to investigate antimicrobial resistance patterns in virulence gene-positive
E. coli
isolates obtained from 340 healthy and diarrheic calves.
Methods and results
A total of 340 fecal swab samples were obtained from diarrheic (n = 170) and healthy (n = 170) calves for 12 months from different farms in Kerman, Iran. The samples were phenotypically analyzed to detect
E. coli
isolates and antibiotic resistance. Also, antimicrobial resistance genes, diarrheagenic
E. coli
pathotypes, and phylogenetic background were screened by PCR. Fifteen percent (51/340) of
E. coli
isolates were positive for at least one of the examined virulence genes (VGs); the prevalence of VGs in
E. coli
isolates from healthy calves (36/170; 21.17%) was higher than that in diarrheic cases (15/170; 8.82%). Out of the 51 VG-positive isolates, six pathotypes including Shiga toxin-producing
E. coli
(STEC; 27.45%), enterotoxigenic
E. coli
(ETEC; 23.52%), enterohemorrhagic
E. coli
(EHEC; 19.6%), necrotoxigenic
E. coli
(NTEC; 19.6%), enteropathogenic
E. coli
(EPEC; 15.68%), enteroinvasive
E. coli
(EIEC; 1.96%) and three hybrid pathotypes including ETEC/STEC, ETEC/EHEC, and STEC/EIEC were detected among the strains. Antimicrobial resistance (AR) was observed in 98.03% of the VG-positive isolates, which was the same for both healthy and diarrheic calves. The maximum prevalence rate of AR was found against trimethoprim/sulfamethoxazole (49.01%; 3/51), while the minimum prevalence rate was against gentamycin (5.88%; 25/51). Among the VG-positives, phylotype A was found to be the most prevalent followed by B1 and D phylotypes.
Conclusions
The prevalence of VG-positive
E. coli
isolates was higher in healthy calves compared to diarrheic cases. AR was widespread among VG-positive isolates. These findings suggest that calves may serve as potential reservoirs of antimicrobial-resistant hybrid pathotypes of
E. coli
.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Three hundred fifteen bacteriological samples were obtained from feces and both external and visceral cavity surfaces of carcasses of 105 healthy buffalo slaughtered in southwest of Iran. Confirmed
...Escherichia coli
isolates were examined for antimicrobial resistance phenotypically and were screened for
stx
1
,
stx
2
, and
eae
genes and their subtypes and assessment of antimicrobial resistance genes by regular PCR and RFLP techniques. One hundred forty-five
E. coli
were isolated from feces (96 isolates) and external (37) and internal (12) surfaces of carcasses. Results showed that the prevalence of STEC, EPEC, and EHEC pathotypes was 2.8%, 0.7%, and 0.7% respectively. Among 6 (4.13%) positive isolates for examined genes, 4 (2.8%) isolates were positive for
stx1
, 3 (2.1%) for
stx2
, and 2 (1.4%) for
eae
gene. The detected genes were classified into
stx
1
a
(4 isolates),
stx
2
a
,
stx
2
b
,
stx
2
c
,
eae
-β, and unknown subtypes. The most prevalent antibiotic resistance gene was
sulII
(11.03%). The
tetB
,
qnrB
,
floR
,
bla
TEM
,
bla
SHV
, and
aad
A
genes were found to a lesser extent, and all isolates were negative for
bla
CTX-15
,
bla
OXA
,
aac(3)-I
,
tetA
,
cat1
,
qnrA
,
sulI
,
dhfrI
, and
dhfrV
genes. Twelve combination patterns of antibiotic-resistant genes were observed. Maximum phenotypically resistance rate was against doxycycline (91.83%), and the minimum was against ceftazidime and florfenicol (2.75%).
E. coli
isolates from feces and carcasses of slaughtered buffalo can be considered a mild reservoir for
stx
and
eae
genes. However, healthy buffaloes could be considered a potential reservoir of multiple antibiotic resistance genes in
E. coli
isolates
.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Three 20-day-old female Cashmere (Raini) goat kids were presented in a sternal recumbency status with 3 weeks history of bilateral mucopurulent nasal discharge, anorexia, lethargy, and jugular ...distention hemato-biochemical profile showed leukocytosis (monocytosis, neutrophilia with bandemia) and a significant increase (
p
< 0.05) in the serum concentrations of total protein and fibrinogen. The goats died 1 week after treatment because of the severity of the disease. At necropsy, multiple pyogenic abscesses in the liver, myocardial abscesses, and fibrous pleural adhesions were observed. Histopathological examination revealed supportive hepatitis, formation of granulation tissue in the epicardial and myocardial layer of the heart and chronic suppurative bronchopneumonia with granulation tissue in the pleura. In bacteriological examination,
Trueperella pyogenes
(
T. pyogenes
) was isolated from the abscess and confirmed by PCR. The isolated bacteria showed the most susceptibility to the cefotaxime and the less susceptibility to oxytetracycline and gentamycin. Overall, this is the first report, which offered this bacterium as a causative agent of the wide ranges of pathological conditions in Cashmere goats. Suitable antimicrobial therapy of which the Clinician should be aware.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Dielectrophoresis (DEP), a precision nonlinear electrokinetic tool utilized within microfluidic devices, can induce bioparticle polarization that manifests as motion in the electric field; this ...phenomenon has been leveraged for phenotypic cellular and biomolecular detection, making DEP invaluable for diagnostic applications. As device operation times lengthen, reproducibility and precision decrease, which has been postulated to be caused by ion gradients within the supporting electrolyte medium. This research focuses on characterizing pH gradients above, at, and below the electrode charging frequency (0.2–1.4 times charging frequency) in an aqueous electrolyte solution in order to extend the parameter space for which microdevice-imposed artifacts on cells in clinical diagnostic devices have been characterized. The nonlinear alternating current (AC) electric fields (0.07 Vpp/μm) required for DEP were generated via planar T-shaped and star-shaped microelectrodes overlaid by a 70 μm high microfluidic chamber. The experiments were designed to quantify pH changes temporally and spatially in the two microelectrode geometries. In parallel, a 50 nm hafnium oxide (HfO2) thin film on the microelectrodes was tested to provide insights into the role of Faradaic surface reactions on the pH. Electric field simulations were conducted to provide insights into the gradient shape within the microelectrode geometries. Frequency dependence was also examined to ascertain ion electromigration effects above, at, and below the electrode charging frequency. The results revealed Faradaic reactions above, at, and below the electrode charging frequency. Comparison experiments further demonstrated that pH changes caused by Faradaic reactions increased inversely with frequency and were more pronounced in the star-shaped geometry. Finally, HfO2 films demonstrated frequency-dependent properties, impeding Faradaic reactions.
