Short-term effect of oral amoxicillin treatment on the gut microbial community composition in farm mink (Neovison vison)

Rookery through rehabilitation: Microbial community assembly in newborn harbour seals after maternal separation

Microbial community assembly remains largely unexplored in marine mammals, despite its potential importance for conservation and management. Here, neonatal microbiota assembly was studied in harbour seals (Phoca vitulina richardii) at a rehabilitation facility soon after maternal separation, through weaning, to the time of release back to their native environment. We found that the gingival and rectal communities of rehabilitated harbour seals were distinct from the microbiotas of formula and pool water, and became increasingly diverse and dissimilar over time, ultimately resembling the gingival and rectal communities of local wild harbour seals. Harbour seal microbiota assembly was compared to that of human infants, revealing the rapid emergence of host specificity and evidence of phylosymbiosis even though these harbour seals had been raised by humans. Early life prophylactic antibiotics were associated with changes in the composition of the harbour seal gingival and rectal communities and surprisingly, with transient increases in alpha diversity, perhaps because of microbiota sharing during close cohabitation with other harbour seals. Antibiotic-associated effects dissipated over time. These results suggest that while early life maternal contact may provide seeding for microbial assembly, co-housing of conspecifics during rehabilitation may help neonatal mammals achieve a healthy host-specific microbiota with features of resilience.

Doxycycline Attenuates Pig Intestinal Microbial Interactions and Changes Microbial Metabolic Pathways

Doxycycline is a therapeutic veterinary antibiotic commonly used in pig breeding. In this study, 27 fattening pigs of 33.5 ± 0.72 kg were divided equally into 3 groups. Doxycycline at 0, 3, and 5 mg/kg body weight was added to the feed in groups CK, L and H. The medication and withdrawal periods were set at 5 and 28 days. The results showed that the doxycycline average concentrations in groups L and H during the medication period were 117.63 ± 13.54 and 202.03 ± 24.91 mg/kg dry matter, respectively. Doxycycline levels were lower than the detection limit after 20 days. Doxycycline did not affect the diversity of the intestinal microbial community structure. The relative abundances of Streptococcus were significantly higher in treatment groups than that in group CK, and Alishewanella, Vagococcus, Cloacibacterium, and Campylobacter abundances were significantly positively correlated with doxycycline concentration. Interestingly, the microbiota cooccurrence network suggested that high doxycycline concentration weakened the interactions among bacteria until day 33. Functional prediction showed that doxycycline significantly altered metabolic pathways related to the cell membrane. The results revealed that the use of doxycycline during pig breeding can affect bacterial abundance during the withdrawal period, and it may affect interactions among bacteria and change the intestinal metabolic pathways.

Impact of oral amoxicillin and amoxicillin/clavulanic acid treatment on bacterial diversity and β-lactam resistance in the canine faecal microbiota

BACKGROUND

Aminopenicillins with or without a β-lactamase inhibitor are widely used in both human and veterinary medicine. However, little is known about their differential impact on the gut microbiota and development of antimicrobial resistance.

OBJECTIVES

To investigate changes in the faecal microbiota of dogs treated with amoxicillin or amoxicillin/clavulanic acid.

METHODS

Faeces collected from 42 dogs (21 per treatment group) immediately before, during and 1 week after termination of oral treatment with amoxicillin or amoxicillin/clavulanic acid were analysed by culture and 16S rRNA gene sequence analysis.

RESULTS

In both groups, bacterial counts on ampicillin selective agar revealed an increase in the proportion of ampicillin-resistant Escherichia coli during treatment, and an increased occurrence and proportion of ampicillin-resistant enterococci during and after treatment. 16S rRNA gene analysis showed reductions in microbial richness and diversity during treatment followed by a return to pre-treatment conditions approximately 1 week after cessation of amoxicillin or amoxicillin/clavulanic acid treatment. While no significant differences were observed between the effects of amoxicillin and amoxicillin/clavulanic acid on microbial richness and diversity, treatment with amoxicillin/clavulanic acid reduced the abundance of taxa that are considered part of the beneficial microbiota (such as Roseburia, Dialister and Lachnospiraceae) and enriched Escherichia, although the latter result was not corroborated by phenotypic counts.

CONCLUSIONS

Our results suggest a limited effect of clavulanic acid on selection of antimicrobial resistance and microbial richness when administered orally in combination with amoxicillin. However, combination with this β-lactamase inhibitor appears to broaden the spectrum of amoxicillin, with potential negative consequences on gut health.

Effects of health related farm-level factors on skin size and quality in commercial mink (Neovison vison) production

This study investigated the potential effects of management and health related factors on the productivity in the commercial mink production, during 2015-2018. Data were available from the database at Kopenhagen Fur, the national veterinary prescription database, VetStat, and the laboratory database at the Center for Diagnostics, Technological University of Denmark. A cross-sectional study, including 1.464 min. farms grouped into 1.187 epidemiological units, was applied. Data were analyzed in two models with different outcomes representing productivity on the mink farms, namely skin size and economical value (value sum) of the produced skin. The studied risk factors included use of vaccines and antibacterials, herd size, associated feed producer, purchases and sales of live animals, breeding results (litter size after weaning), Aleutian mink disease virus antibody (AMDV status) and stamping out, and laboratory test results. Vaccination against mink enteritis parvovirus and high breeding results were found to have a positive association with both outcomes, skin size and value sum. Both outcomes also varied significantly between farm clusters associated with different feed producers. Significant effects of antibacterial treatment were found, but the results were complex with both positive and negative associations with the outcome variables, depending on season and interactions with feed producer. Positive effects on antibacterial prescription on skin size were observed, except for farms associated with two small feed producers, known to have a variable microbiological feed quality. In farms receiving feed of very high quality, the positive effect of antibacterial prescription was marginal. CONCLUSIONS: The use of mink data has allowed us to assess the impact of feed quality as well as antibacterial prescription on productivity. The results showed a positive quantitative effect of vaccination against mink enteritis parvovirus on skin size and value, with an optimal effect by vaccination of the whole litter. Antibacterial prescription in the growth period, particularly around weaning, was found to have a positive quantitative effect on productivity in some farms, and the results suggest that the effect was associated with the feed quality. Use of antibacterials to counteract negative effects of low feed quality is not in accordance with principles for prudent use of antibacterials.

The microbiota of farmed mink (Neovison vison) follows a successional development and is affected by early life antibiotic exposure

On many mink farms, antibiotics are used extensively during the lactation period to reduce the prevalence and severity of pre-weaning diarrhoea (PWD) in mink kits (also referred to as greasy kit syndrome). Concerns have been raised, that routine treatment of PWD with antibiotics could affect the natural successional development of the gut microbiota, which may have long lasting consequences. Here we investigated the effects of early life antibiotic treatment administered for 1 week (postnatal days 13–20). Two routes of antibiotic administration were compared to a non-treated control group (CTR, n = 24). Routes of administration included indirect treatment, through the milk from dams receiving antibiotics by intramuscular administration (ABX_D, n = 24) and direct treatment by intramuscular administration to the kits (ABX_K, n = 24). A tendency for slightly increased weight at termination (Day 205) was observed in the ABX_K group. The gut microbiota composition was profiled by 16S rRNA gene sequencing at eight time points between Day 7 and Day 205. A clear successional development of the gut microbiota composition was observed and both treatment regimens caused detectable changes in the gut microbiota until at least eight days after treatment ceased. At termination, a significant positive correlation was identified between microbial diversity and animal weight.

Evaluation of antibiotic-induced behavioral changes in mice

Gut microbiota (GM) plays a critical role in health maintenance. Previous reports connected GM with metabolic, immunologic and neurologic pathways. The main purpose of the current investigation was to study whether antibiotic-induced disturbances of GM affects psychological or behavioral conditions on mice as animal model. Mice were exposed to clindamycin or amoxicillin, and their behaviors were evaluated. Antibiotic-treated groups displayed reduced recognition memory and increased depression. No significant changes in the locomotor activity and anxiety were observed. Our data suggested that changes in GM composition by antibiotics may lead to the cognitive and behavioral deficit.

Stability of antibacterial and coccidiostat drugs on chicken meat burgers upon cooking and in vitro digestion

The impact of culinary practices - oven or microwave cooking combined with herbs and/or beer - on antibacterial and coccidiostat drugs stability and bioaccessibility in chicken meat was evaluated. Fourteen compounds from 6 classes (β-lactams, tetracyclines, sulfonamides, fluoroquinolones, macrolides, and coccidiostats) were monitored after cooking and in vitro digestion (INFOGEST protocol) at two fortification levels. Depending on their reduction, the presence of transformation products derived from cooking or digestion was investigated. In general, compounds were stable during cooking except amoxicillin, chlortetracycline and tylosin (reductions > 50%). Molecular rearrangement and dechlorination reactions are the most probable transformations derived from cooking. Adding herbs/beer does not benefit their reductions. During in vitro digestion, maximum bioaccessibilities of 60% were observed for all quantified compounds. As drugs and bile salts interact, increasing the absorption of lipophilic drugs, their bioaccessibility predictions must not be based only on the determination of their free form using LC-MS/MS.

Compositional alterations of gut microbiota in children with primary nephrotic syndrome after initial therapy

Background

Primary nephrotic syndrome (PNS) is a common glomerular disease in children. T cell dysfunction plays a crucial role in the pathogenesis of PNS. Moreover, dysbiosis of gut microbiota contributes to immunological disorders. Whether the initial therapy of PNS affects gut microbiota remains an important question. Our study investigated compositional changes of gut microbiota after initial therapy.

Methods

Fecal samples of 20 children with PNS were collected before and after 4-week initial therapy. Total bacteria DNA were extracted and the V3-V4 regions of bacteria 16S ribosomal RNA gene were sequenced. The composition of gut microbiota before and after initial therapy was analyzed by bioinformatics methods. The function of altered gut microbiota was predicted with PICRUSt method.

Results

The richness and diversity of gut microbiota were similar before and after 4-week initial therapy. Gut microbiota at the phylum level was dominated by four phyla including Firmicutes, Proteobacteria, Bacteroidetes and Actinobacteria, but the increased relative abundance after initial therapy was found in Deinococcus-Thermus and Acidobacteria. At the genus level, the increased abundance of gut microbiota after initial therapy was observed in short chain fat acids (SCFA)-producing bacteria including Romboutsia, Stomatobaculum and Cloacibacillus (p < 0.05). Moreover, the predicted functional profile of gut microbiota showed that selenocompound metabolism, isoflavonoid biosynthesis and phosphatidylinositol signaling system weakened after initial therapy of PNS.

Conclusions

Initial therapy of PNS increased SCFA-producing gut microbiota, but might diminish selenocompound metabolism, isoflavonoid biosynthesis and phosphatidylinositol signaling system in children.

Antibiotic-Induced Perturbations Are Manifested in the Dominant Intestinal Bacterial Phyla of Atlantic Salmon

The intestinal microbiota of certain farmed fish are often exposed to antimicrobial substances, such as antibiotics, that are used to prevent and treat bacterial diseases. Antibiotics that kill or inhibit the growth of harmful microbes can rapidly alter intestinal microbial diversity and composition, with potential effects on the host health. In this study, we have elucidated the impact of two antibiotics, florfenicol and oxolinic acid, by employing a high-throughput 16S rRNA gene amplicon sequencing technique on the distal and mid intestinal microbial communities of Atlantic salmon (Salmo salar). For this, Atlantic salmon were offered diets with or without antibiotics. We then investigated the bacterial communities in the intestinal mucus of the fish. Our results showed that antibiotic exposure shifts the intestinal microbial profile differentially. In addition, the bacterial compositions of the control and antibiotic-fed groups were significantly different. Antibiotic feeding altered the composition and abundance of the dominant bacterial phyla, namely Proteobacteria, Actinobacteria, Firmicutes, Spirochaetes, Bacteroidetes, Tenericutes, and Thermotogae. The bacterial association network analysis also indicated the differential pattern of co-occurrence of bacteria in the three study groups. The results regarding the differences in the structure and association of the intestinal microbiota of Atlantic salmon after florfenicol and oxolinic acid feeding can be employed to attenuate the adverse effects of antibiotic feeding on fish.

Comparing the treatment effect of narrow spectrum antimicrobial, probiotic and fluid with amoxicillin in mink kits (Neovison vison) with pre-weaning diarrhea

Pre-weaning diarrhea in mink kits (PWD), also known as "sticky kits" is a multifactorial syndrome of considerable concern in the mink production. Evidence based treatment protocols are not available, and treatment is therefore empirical and often based on the use of antimicrobials. The purpose of the study was to test the effect of 3 alternative treatments to a standard antibiotic treatment, to characterize the study groups microbiologically, and finally to compare the intestinal microbiota of the different treatment groups at the age of 42 days. In total, 226 one to three week old mink kits with PWD from 36 litters were treated with either 1) Lactobacillus reuteri, 2) benzylpenicillin, 3) Ringer lactate or 4) amoxicillin (controls). Effects of the treatments were measured as weight gain from day 0 to day 15 and mortality. Multivariable linear mixed model regression showed no significant difference in weight gain between probiotic-, penicillin or fluid-treated mink kits and the amoxicillin treated controls. There was also no significant difference in mortality risk between the treatment groups. Bacterial culture and next generation sequencing of the viral contents showed that the study groups were uniform with a high frequency of Staphylococcus intermedius group (SIG) bacteria, Escherichia coli, Enterococcus hirae, Mamastrovirus and Sapovirus which were representative for mink kits with PWD. 16S sequencing results of the bacterial microbiota, when the kits were 42 days old were dominated by clostridia in all groups and showed no clear differences in the bacterial composition between the different treatment groups.

Transfer of amoxicillin to suckling mink (Neovison vison) kits via the milk from dams treated orally or intra-muscularly

Treatment of mink kits with pre-weaning diarrhea (PWD) can be time-consuming and expensive for the farmer, and the efficacy of the treatment procedure may be questioned. Evidence-based treatment protocols for application on affected animals at farms with outbreaks of PWD are lacking. In Denmark, the dams are sometimes treated with amoxicillin, however, it is unknown if it is passed on to the mink kits via the milk. The aim of the present study was to investigate if amoxicillin is transferred via the milk to the kits after oral (PO) and intramuscular (IM) treatment, respectively, of the dam. Moreover, we estimated the concentrations of amoxicillin continuously in serum from the kits up to 8 h after administration. The concentration of amoxicillin was not affected by the route of administration (P = .64) and serum reached the highest level after 8 h (34 ng/mL, CI_95% = [24.3-47.7]). The serum concentrations of amoxicillin in the mink kits achieved within 8 h were judged too low to exert antimicrobial impact on relevant bacterial species.

Investigation of the viral and bacterial microbiota in intestinal samples from mink (Neovison vison) with pre-weaning diarrhea syndrome using next generation sequencing

Pre-weaning diarrhea (PWD) in mink kits is a common multifactorial syndrome on commercial mink farms. Several potential pathogens such as astroviruses, caliciviruses, Escherichia coli and Staphylococcus delphini have been studied, but the etiology of the syndrome seems complex. In pooled samples from 38 diarrheic and 42 non-diarrheic litters, each comprising of intestinal contents from 2-3 mink kits from the same litter, the bacterial populations were studied using Illumina Next Generation Sequencing technology and targeted 16S amplicon sequencing. In addition, we used deep sequencing to determine and compare the viral intestinal content in 31 healthy non-diarrheic and 30 diarrheic pooled samples (2-3 mink kits from the same litter per pool). The results showed high variations in composition of the bacterial species between the pools. Enterococci, staphylococci and streptococci dominated in both diarrheic and non-diarrheic pools. However, enterococci accounted for 70% of the reads in the diarrheic group compared to 50% in the non-diarrheic group and this increase was at the expense of staphylococci and streptococci which together accounted for 45% and 17% of the reads in the non-diarrheic and diarrheic group, respectively. Moreover, in the diarrheic pools there were more reads assigned to Clostridia, Escherichia-Shigella and Enterobacter compared to the non-diarrheic pools. The taxonomically categorized sequences from the virome showed that the most prevalent viruses in all pools were caliciviruses and mamastroviruses (almost exclusively type 10). However, the numbers of reads assigned to caliciviruses were almost 3 times higher in the diarrheic pools compared the non-diarrheic pools and Sapporo-like caliciviruses were more abundant than the Norwalk-like caliciviruses. The results from this study have contributed to the insight into the changes in the intestinal microbiota associated with the PWD syndrome of mink.