Effects of Yarrow (Achillea millefolium) Essential Oil Compared with Growth Promoter Antibiotic and Probiotic on Growth Performance, Meat Quality, and Immune Response of Broiler Chickens

Introduction: Application of growth-promoting antibiotics in poultry nutrition improves growth, feed intake, feed conversion ratio and reduces mortality. But, due to their persistent effects and increased drug resistance to pathogenic bacteria and the transmission of bacteria to humans through the food chain, the European Union banned their use. One of the natural alternatives is medicinal plants. Because plant products for reasons such as availability, ease of use, reduction of side effects, antibacterial and antioxidant properties, were used to treat some diseases in humans and animals. Among these medicinal plants we can mention yarrow with the scientific name of Achillea millefolium. This plant in addition to high antimicrobial and antioxidant properties; has antifungal properties, stimulates appetite, improves digestion and feed intake, improves the condition of the gastrointestinal tract, etc. This plant also accelerates digestion and shortens the passage of food through the gastrointestinal tract by increasing bile production and enzymatic activity. On the other hand, probiotics are living microorganisms of a nonpathogenic and nontoxic in nature that improve gastrointestinal health and improve performance in birds by improving intestinal microbial balance. According to these cases, this study was performed to evaluate the effect of yarrow essential oil in comparison with a growth-promoting antibiotic and probiotic on performance of broiler chickens.Materials and Methods: A total of 200 day-old male broiler chicks (Ross 308) were studied in a completely randomized design with five treatments, and four replicates. Experimental diets were: 1) basal diet (control), 2 and 3) basal diets supplemented with 100 and 200 mg/kg of yarrow essential oil, respectively, 4) basal diet supplemented with 200 mg/kg probiotic, and 5) basal diet supplemented with 500 mg/kg antibiotic (flavophospholipol). Body weight and feed intake were measured at the end of each growing period and were used to calculate Performance parameters such as body weight gain, and feed conversion ratio. At the end of the experiment, one bird per each replicate was slaughtered for meat quality tests, including measurements of TBARS, pH, water holding capacity, dripping loss and antibody titer. For TBARS, the amount of fat oxidation of the sample was measured by measuring the amount of malondialdehyde and the microtiter hemagglutination method was used to determine the antibody titer produced against sheep erythrocytes.Results and Discussion: During the whole experimental period, birds received yarrow essential oil at 100 mg/kg diet, showed significantly higher body weight and lower FCR compared to the control group(P <0.05).  The lowest feed intake was observed in birds that were fed from the level of 200 mg/kg of yarrow essential oil. However, this effect was significant only in comparison with antibiotic treatment, which showed the highest feed intake (P <0.05). Different results have been reported in this regard which can be related to the type of plant, the amount of active ingredients, the level of the medicinal plant used and the interactions with other components of the diet. The TBARS index, indicating lipid oxidation of meat, in chickens fed with different levels of yarrow essential oil and probiotic were lower compared to the control group and antibiotics. In vitro, researchers have shown that plant essential oils, such as yarrow alkaloids, can reduce free radicals and can be a good alternative to synthetic antioxidants. Also in the study of using a mixture of plant extracts increased the concentration of phenols and decreased the amount of TBARS in the meat of broilers. pH, water holding capacity, dripping loss and cooking loss were not affected by the dietary treatments. The antibody titer against sheep red blood cell (SRBC) was lower in the control group in compare to those fed different levels of yarrow essential oil. In some studies, yarrow has increased humoral immunity with its antimicrobial and antioxidant properties; but, the amount used and the concentration of plant material were also effective.Conclusion: Based on the results, the use of 100 mg/kg yarrow essential oil increased body weight, improved feed conversion ratio and also increased antibody titer at 42 days of age. On the other hand, the TBARS index in chickens fed with different levels of yarrow essential oil was lower in compare to control group. Finally, according to the results, it can be concluded that the use of yarrow essential oil at the level of 100 mg/kg can be a good substitute to antibiotics in poultry nutrition

Prevalence of Resistance to Quinolone and Fluoroquinolone Antibiotics and Screening of qnr Genes Among Escherichia coli Isolates From Urinary Tract Infection

Background: Antibiotic resistance (AR) is an important challenge in prevention, treatment and control of infectious diseases and is a public health threat for human. Escherichia coli strains are the major causes of urinary tract infections (UTIs). Objective: This research aimed to determine prevalence of resistance to quinolone and fluoroquinolone antibiotics and screen qnr genes among E. coli isolates from UTIs. Materials and Methods: A total of 105 E. coli isolates were obtained from UTI cases in Bojnord city (northeast of Iran) and confirmed by biochemical tests. All strains were studied to determine their resistance to 3 antibiotics including ciprofloxacin, nalidixic acid, and levofloxacin via disk diffusion method. Moreover, the frequency of qnrA, qnrB and qnrS genes and phylogroups was studied by conventional Polymerase chain reaction (PCR). Results: In this study, prevalence of phenotypic AR to ciprofloxacin, nalidixic acid and levofloxacin was 47.6%, 44.8% and 38.1%, respectively. Three isolates were positive for qnrS and 1 isolate was positive for qnrA. Seven phylogenetic groups were also identified as follows: 18% A0, 6.7% A1, 7.6% B1, 1.9% B22, 23.8% B23, 15.3% D1 and 26.7% D2. Conclusion: Prevalence of qnr genes was very low; thus, other types of qnr and plasmid-mediated quinolone resistance genes were probably responsible for the resistance. Phenotypic AR to the 3 antibiotics was found in approximately half of E. coli strains. It is strongly recommended that antibiogram tests should be done before prescribing the ciprofloxacin, nalidixic acid and levofloxacin for UTIs

Detection of Fimbrial Genes, Antibiotic Resistance Profile and Phylogenetic Background of Uropathogenic E. coli Isolated from Clinical Samples in Karaj City, Iran

Background:   The aim of the present study was to determine the prevalence of phylogenetic groups/subgroups, fimbrial genes, and antibiotic susceptibility of E. coli isolated from urinary tract infections in Karaj city, Iran. Methods:  A total of 107 E. coli isolates were confirmed by standard bacteriological tests. The phylogenetic group, fimbrial genes and antibiotic resistance genes was determined by PCR method. Antibiotic resistance of all the isolated E.coli against nine antimicrobial agents was determined by disk diffusion method. Results:   PCR assays showed the prevalence of fimbrial genes among the studied isolates were 31.7% and 9.3% for papEF and afaBC, respectively. Most of papEF genes were placed in D phylogroup (18.6%) and D1 subgroup (14.01%) and the percentage of afaBC (2.8%) were similar in B1, B2 and D phylogroups. The frequency of tetA and tetB genes were 22.4% and 17.7%. Isolates which contained tetA were distributed mainly in D group (14.01%) and those which contained tetB were divided in D group (7.48%). Antimicrobial susceptibility testing showed the maximum resistance rate to cephalexin (CN: 100%) and the minimum resistance level to ciprofloxacin (CP: 36.5%). Conclusion:   The present study showed that phylogenetic groups A and D were predominant. Virulence factors such as papEF and afaBC belonged to D phylogenetic group. Multidrug resistance E. coli isolates tends to be in the non-B2 phylogenetic groups. Due to high antibiotic resistance, appropriate control should be considered in medicine to control the development of novel resistant isolates

Molecular screening of SARS‐CoV‐2 in dogs and cats from households with infected owners diagnosed with COVID‐19 during Delta and Omicron variant waves in Iran

Abstract Objective The emergence of SARS‐CoV‐2 infection in dogs and cats in different countries worldwide raises concerns that pets are at a higher risk for spreading or transmitting of SARS‐CoV‐2 to humans and other pets and increased the research works about the zoonotic aspects and natural routes of infection in companion animals. The current study aimed to detect the SARS‐CoV‐2 in household dogs and cats living with COVID‐19 positive owners. Methods Deep oropharyngeal and rectal swabs were collected from 30 household pets (20 cats and 10 dogs) living with COVID‐19 positive owners from April 2021 to 2022 in Kerman, Iran. All dogs’ and cats’ samples were tested by real‐time reverse transcription polymerase chain reaction for detection of SARS‐CoV‐2. Results Two household cats out of 20 examined (10%) were positive for SARS‐CoV‐2, whereas none of the examined dogs were positive for SARS‐CoV‐2. The two cats positive for SARS‐CoV‐2 were symptomatic and suffered from severe anorexia with maximum contact with their infected owners. Conclusion This study reported the presence of SARS‐CoV‐2 in household cats in close contact with COVID‐19 positive owners during the circulation of new SARS‐CoV‐2 variants (Delta and Omicron) in Iran and suggested that the transmission may have occurred from owners to their cats. Therefore, infected owners should eagerly limit close contact with their pets during COVID‐19 illness

High prevalence of β-lactam and fluoroquinolone resistance in various phylotypes of Escherichia coli isolates from urinary tract infections in Jiroft city, Iran

Abstract Background Urinary tract infection (UTI) is one of the most prevalent infectious diseases with worldwide health threatening. Antimicrobial resistant strains of Escherichia coli (E. coli) are a common cause of UTI which were identified as a treatment challenge. This study aimed to assay the prevalence of common β-lactam resistance genes including bla TEM, bla SHV, bla CTX-M and bla CMY and phenotypic resistance to commonly used β-lactam and fluoroquinolone antibiotics in UTIs. These factors were evaluated in various phylogenetic groups (phylotypes) of E. coli isolates. Real-time PCR was applied to detect β-lactam resistance genes and conventional PCR was used to determine the phylotypes. Phenotypic resistance against β-lactams (ceftazidime, cefotaxime, aztreonam and ceftriaxone) and fluoroquinolones (ciprofloxacin) were identified by the disc diffusion technique. The ability of extended spectrum β-lactamases (ESBLs) production in E. coli isolates was detected using the combined disc diffusion method. Results The prevalence of resistance genes were 89.6% for bla TEM, 44.3% for bla CTX-M, 6.6% for bla SHV and 0.9% for bla CMY. The two high prevalent phylotypes were B2 (29.2%) and D (17.9%) followed by E (14.1%), F (9.4%), C (6.6%) and 10.3% of isolates were unknown in phylotyping. Disc diffusion results showed high prevalence of antibiotic resistance to cefotaxime (88.6%), aztreonam (83%), ceftireaxon (77.3%), ceftazidime (76.4%) and ciprofloxacin (55.6%). Totally, 52.8% of isolates were found as phenotypical ESBL-producers. Conclusions This study’s results confirmed an explosion of antibiotic resistance amongst E. coli isolates from UTI against β-lactams and fluoroquinolones. Findings explain the necessity of deep changes in quantity and quality of drug resistance diagnosis and antibiotic therapy strategies. More studies are suggested to better and confident evaluations

Pathogenic potential of Shiga toxin-producing Escherichia coli strains of caprine origin: virulence genes, Shiga toxin subtypes, phylogenetic background and clonal relatedness

Abstract Background All over the world, Shiga toxin-producing Escherichia coli (STEC) are considered as important zoonotic pathogens. Eight serogroups have the greatest role in the outbreaks and diseases caused by STEC which include O26, O45, O103, O111, O113, O121, O145 and O157. Ruminants, especially cattle are the main reservoirs but the role of small ruminants in the epidemiology of human infections has not been thoroughly assessed in many countries. The objective of this research was to investigate the pathogenic potential of the STEC strains isolated from slaughtered goats. In this study, a total of 57 STEC strains were recovered from 450 goats and characterized by subtyping of stx genes, O-serogrouping, phylo-typing and DNA fingerprinting. Results Amongst 57 STEC strains isolated from goats, the prevalence of stx1 was significantly more than stx2 (98.2% vs. 24.5%; P ≤ 0.05), and 22.8% of strains harbored both stx1 and stx2 genes. Three (5.2%) isolates were characterized as EHEC, which carried both eae and stx genes. A total of five stx-subtypes were recognized namely: stx1c (94.7%), stx1a (53.7%), stx2d (21%), stx2c (17.5%), and stx2a (15.7%). In some parts of the world, these subtypes have been reported in relation with severe human infections. The stx subtypes predominantly occurred in four combinations, including stx1a/stx1c (35%), stx1c (31.5%), stx1c/stx2a/stx2c/stx2d (5.2%) and stx1c/stx2c/stx2d (%5.2%). In serogrouping, the majority of STECs from goats did not belong to the top 8 serogroups but two strains belonged to O113, which has been recognized as an important pathogenic STEC in Australia. Interestingly, none of stx + eae + isolates belonged to the tested serogroups. In phylo-typing the isolates mostly belonged to phylo-group B1 (82.4%), followed by phylo-group A (12.3%). STEC strains showed a substantial diversity in DNA fingerprinting; there were 24 unique ERIC-types (with a ≥95% similarity) among the isolates. Conclusions Despite the fact that the top 8 STEC serogroups were uncommon in caprine strains, the presence of highly pathogenic stx subtypes indicates that small ruminants and their products can be considered as an overlooked public health risk for humans, especially in developing countries which consume traditional products