Short communication: In vitro Evaluation of Resistance of Rhipicephalus (Boophilus) microplus against Three Widely Used Ixoidicides

Espinoza, Joseph; Flores, Byron; Jerez, Jeffery; Sheleby-Elías, Jessica

Veterinarija ir Zootechnika

Similar articles

Determination of STAT5 and GH Genes Polymorphisms and Their Influence on Productivity Traits of Beef Cattle Reared in Lithuania

Nijolė Pečiulaitienė Ramutė Mišeikienė Kristina Morkūnienė All authors (7)

Pub. online: 30 Nov 2024 Type: Article

Open Access

Journal: Veterinarija ir Zootechnika Volume 82, Issue 1 (2024): Veterinarija ir Zootechnika, pp. 42–46

Abstract

Investigations on Effect of Bacillus Licheniformis BL11 Probiotic Formula on Antimicrobial Resistance in Commensal Poultry E. Coli Isolates

Dima Dobreva Valentina Urumova

Pub. online: 22 Aug 2024 Type: Research Article

Open Access

Journal: Veterinarija ir Zootechnika Volume 81, Issue 2 (2023): Veterinarija ir Zootechnika, pp. 44–53

Abstract

The aim of the present study was to investigate phenotype resistance profiles and some

genetic determinants in resident E. coli bacteria isolated from broilers whose ration was supplemented

with a probiotic formula containing a Bacillus licheniformis BL11 strain (Huvepharma, Belgium).

For bacteriological examination, cloacal swabs were collected at various intervals throughout the

study: from day-old, 14-day-old and 28-day-old chickens. A total of 300 swabs were collected for

bacteriological examination: 150 from control and 150 from probiotic-supplemented chickens. The

total number of E. coli strains isolated from control and experimental broilers was 214: 107 strains

from the control group and another 107 from birds that received a probiotic with the feed.

Among E. coli isolates from day-old broilers in the experimental group, the highest resistance

rate was observed against gentamicin (69.0%), followed by that against ampicillin and amoxicillin/

clavulanic acid (52.4%). Escherichia coli isolated from probiotic-supplemented broilers at 14 days

of age demonstrated statistically significantly higher rate of resistance (P ≤ 0.05) against cefotaxime

(51.6%) and ceftazidime (38.7%) compared with isolates from the control group (12.0%). Also, the

prevalence of E. coli strains resistant against amoxicillin/clavulanic acid in supplemented broilers

(35.5%) was insignificantly lower than the respective rate in control chickens (48.0%). At 28 days

of age, the resistance against ciprofloxacin in poultry E. coli isolates in probiotic-fed broilers was

significantly higher (P ≤ 0.01) than the resistance rate in non-supplemented birds (85.3% and 52.7%,

respectively). The resistance to ampicillin among the isolates from experimental broilers was statistically

significantly more common (P ≤ 0.01), i.e., 82.3%, as well as against third generation cephalosporins

(44.1%, 41.2%). The genetic analysis of resistance in commensal E. coli isolates revealed the presence

of bla CTX-M-1, tetA and QnrS genes. In conclusion, we should note that in our study related to the use of

Bacillus licheniformis BL 11 strain, a probiotic formula in broilers, no basic differences were observed

both in terms of the prevalence of resistance to chemotherapeutics and in terms of economic indicators

in the broilers in the control and experimental groups.

Microbiological Studies on the Prevalence of Staphylococcus Spp., Involved in the Etiology of Mastitis in Cattle and their Susceptibility to Antimicrobial Agents

Mariana Nikolova Valentina Urumova

Pub. online: 27 Feb 2023 Type: Research Article

Open Access

Journal: Veterinarija ir Zootechnika Volume 80, Issue 2 (2022): Veterinarija ir Zootechnika, pp. 29–36

Abstract

For the period between June 2020 and -March 2022, a total of 8 dairy cattle farms were surveyed in terms of the prevalence of clinical and subclinical mastitis. Four of them were located in Northern Bulgaria (Targovishte, Shumen and Dobrich districts) and another four in Southern Bulgaria (Stara Zagora, Plovdiv and Haskovo districts). In these target farms, a rapid mastitis screening test was initially performed to detect the presence of subclinical mastitis or samples with high somatic cell counts. A total of 312 milk samples were obtained from milk quarters who reacted with 3+ or 4+ to which 34 samples of inflammatory exudate from cows with clinical mastitis were added. During the microbiological investigation of the 346 samples, 272 of them (79.1%) were bacteriologically positive. Streptococcus spp., were isolated from 151 samples (55.5%). The second most common species was Staphylococcus spp., detected in 110 (40.4%) of the tested samples. In total, the Grampositive cocci finding exceeded 95% of the microbial species. The remaining 11 (4.0%) isolates belonged

to another 6 taxa. These included four strains identified by prior phenotypic identification as Trueperella pyogenes, three Escherichia coli isolates, and one strain of each Pasteurella multocida, Nocardia asteroides, Klebsiella pneumoniae, and Acinetobacter spp. Staphylococci were also studied for their sensitivity to 11 chemotherapeutic agents. The highest percentage of resistance (50%) was determined to lincomycin, followed by that to tetracycline (37.3%), and beta-lactams ampicillin (24.5%), and oxacillin (13.6%). The resistance rates to cefoxitin and cephalotin were 5.5% and 0.9% respectively. Also, lower values of resistant strains were observed for the combination

of trimethoprim/sulfonamides (7.3%), ciprofloxacin (1.8%), and rifampicin (0.9%). Resistance to gentamicin and amoxicillin/ clavulanic acid was not established. Minimum inhibitory concentrations were determined for the studied chemotherapeutics, with the highest MIC90 values of 128 μg/mL and 2 μg/mL for tetracycline and lincomycin, and the lowest MIC90 values of 0.001 μg/mL for rifampicin and ciprofloxacin, respectively. A MIC90 of 0.125 μg/mL was obtained for oxacillin, 1.5 μg/mL for trimethoprim/sulfonamides and 1.0 μg/mL for ampicillin, cephalotin and cefoxitin.

RSS

Export citation

Copy and paste formatted citation

Download citation in file

Authors