Antibiotic susceptibility of Lactobacillus strains isolated from domestic geese

Occurrence and spread of antibiotic-resistant bacteria on animal farms and in their vicinity in Poland and Ukraine-review

Intensive animal farming emits to the environment very high concentrations of bioaerosol, mainly composed of microorganisms, including antibiotics resistant strains, and their derivatives. Poland is a significant producer of poultry and swine in Europe; Ukraine is located in the immediate vicinity of Poland and the EU. Thus, the review focuses on the presence of potentially pathogenic and antimicrobial-resistant zoonotic bacteria and antimicrobial genes in the environment of farms and food of animal origin in Poland and Ukraine. Existing data confirms presence of these bacteria in the food animal origin chain environment in both countries. However, it is difficult to compare the scale of multidrug-resistant bacteria (e.g. MRSA, ESBL) dissemination in Poland and Ukraine with other EU countries due to lack of more extensive studies and large-scale monitoring in these two countries. A series of studies concerning resistance of pathogenic bacteria isolated from livestock environment have been published in Poland but usually on single farms with a very limited number of samples, and without a genotypic drug resistance marking. From Ukraine are available only few reports, but also disturbing. The risk of antibiotic-resistant bacteria transmission does not only concern animal farming, but also other facilities of animal origin food supply chains, especially slaughterhouses.

Anti-cancer Substances and Safety of Lactic Acid Bacteria in Clinical Treatment

Lactic acid bacteria (LAB) are a kind of Gram-positive bacteria which can colonize in the biological gastrointestinal tract and play a variety of probiotic roles. LAB have a wide range of applications in industry, animal husbandry, planting, food safety, and medical science fields. Previous studies on LAB have typically concentrated on their effects on improving the digestion and absorption of the gastrointestinal tract, regulating the balance of the microflora, and inhibiting the production and accumulation of toxic substances. The resistance of LAB to cancer is a topic of growing interest and relevance. This paper provided a summary of bio-active substances of LAB when they act against cancer, as well as the safety of LAB in clinical cancer treatment. Moreover, this paper further discussed several possible directions for future research and the potential application of LAB as anti-cancer therapy.

Assessing the Impact of Flavophospholipol and Virginiamycin Supplementation on the Broiler Microbiota: a Prospective Controlled Intervention Study

The antibiotic growth promoters (AGPs) flavophospholipol and virginiamycin have been widely used for decades in food animal production. AGP activity is believed to be partly modulated by gut microbial composition although exact AGP-induced changes remain unclear. In a controlled intervention study, we studied the effect of flavophospholipol and virginiamycin on the broiler chicken ileal microbiota spanning from birth to 39 days. Using 16S rRNA gene profiling and prediction of metabolic activity, we show that both AGPs result in dynamic microbial shifts that potentially increase anti-inflammatory mechanisms and bioavailability of several essential nutrients by decreasing degradation (flavophospholipol) or increasing biosynthesis (virginiamycin). Further, virginiamycin-supplemented broilers showed increased colonization with potentially pathogenic bacteria, Clostridium perfringens, Campylobacter, and Escherichia/Shigella spp. Overall, we show that both AGPs induce microbial changes potentially beneficial for growth. However, the increase in (foodborne) pathogens shown here with virginiamycin use could impact not only broiler mortality but also human health. IMPORTANCE Antibiotic growth promoters (AGPs) are commonly used within poultry farming to increase muscle growth. Microbial composition in the gut is known to be influenced by AGP use although exact AGP-induced changes remain unclear. Utilizing 16S rRNA gene profiling, this study provides a first head-to-head comparison of the effect of the two most commonly used AGPs, flavophospholipol and virginiamycin, on the broiler chicken ileum microbiota over time. We found that supplementation with both AGPs altered ileal microbial composition, thereby increasing potential bioavailability of essential nutrients and weight gain. Flavophospholipol showed a slight benefit over virginiamycin as the latter resulted in more extensive microbial perturbations including increased colonization by enteropathogens, which could impact broiler mortality.

Occurrence, effects and behaviour of the antibiotic lincomycin in the agricultural and aquatic environment - A review

Lincomycin, an antibiotic commonly used in veterinary medicine, is frequently detected within the agricultural environment. The active compound enters the aquatic environment after manure application via infiltration or surface run-off, where it may negatively affect non-target organisms and contribute to the development and spread of resistant genes. However, a review on the fate of lincomycin within the agricultural and aquatic environment is lacking. Hence, to provide an overview, the main part of this paper summarizes the current literature on the occurrence, effects and behaviour of lincomycin in all relevant environmental compartments, including manure, soil, surface water and groundwater. Lincomycin was regularly detected in all environmental compartments and even in the food chain, appeared to sorb temporarily and mainly in its cationic microspecies, and dissipated after time periods that could cover days, months, or years, depending on the compartment and conditions. As noticed during the literature research conducted, information on the attenuation of lincomycin in terms of biological degradation in the aquatic environment is widely lacking, although it seems that biodegradation is the major removal mechanism. Therefore, a laboratory study, implemented by means of batch experiments, was carried out in order to evaluate the biological degradation of lincomycin in the aquatic environment. First order degradation started after a start-up phase of 10-14 days with a degradation rate constant of 0.55 d^-1 and a half-life time of 30 h. Further, the degradation rate constant was found to be independent of initial concentrations as long as concentrations did not exceed a concentration level at which the bacteria were inhibited, as it was the case in this study at a concentration of 10 mg L^-1. Biodegradation was confirmed as an important degradation pathway for LIN in the aquatic environment.

Biodiversity of Ligilactobacillus salivarius Strains from Poultry and Domestic Pigeons

Simple Summary

Ligilactobcillus salivarius is a Gram-positive bacterium that commonly colonizes the mucous membranes of the digestive tracts of humans and animals, including birds. It belongs to the group of lactic acid bacteria which, by producing lactic acid, acidify the intestinal environment and limit the development of undesirable intestinal microflora. In addition, L. salivarius can produce other antimicrobial substances, such as bacteriocins and hydrogen peroxide. Due to limiting the development of unfavourable microflora and other health-promoting effects, L. salivarius bacteria are considered as potential probiotics that may increase animal health, and thus animal production indicators. In this work, we undertook research on the characteristics of L. salivarius strains from chickens, geese, turkeys and domestic pigeons. We showed great variation in phenotypic and genotypic traits between strains and the evolutionary adaptation of L. salivarius strains to the colonization of a specific host. The results of the study contribute to knowledge of the characteristics of the species L. salivarius and may be useful in the selection of probiotic strains.

Abstract

Ligilactobacillus salivarius is an important member of the human and animal gut microbiota, and selected strains are promising probiotics, but knowledge of the characteristics of avian isolates is still limited. In this study, we examined selected phenotypic and genotypic traits of 33 L. salivarius strains from geese, chickens, turkeys and pigeons. The strains varied in terms of cell size, colony morphology, broth growth characteristics, biofilm formation, tolerance to bile, hydrophobicity and phenotypic and genotypic antibiotic resistance profiles. Large variation among strains was noted for the utilization of sorbitol, salicin, trehalose, rhamnose, inulin and N-acetyl-D-glucosamine. The presence of genes related to sugar metabolism, i.e., mipB, tktA, rhaB and LSL_1894, was not always correlated with the biochemical phenotypic profile. Correlations were recorded between the host and utilization of certain sugars as well as tolerance to bile. The repA-type megaplasmid and genes coding for Abp118 bacteriocin were detected in 94% and 51.5% of L. salivarius strains, respectively. Phylogeny based on groEL gene sequences was partly correlated with the origin of the strains and revealed an evolutionary distance between L. salivarius strains from humans and birds. The results of the study contribute to knowledge of the characteristics of the species L. salivarius. Intraspecies variations of L. salivarius strains may affect their ability to colonize specific niches and utilize nutrients and reveal potential strain-dependent effects on host health.

Phenotypic and genotypic antimicrobial resistance profiles of fecal lactobacilli from domesticated pigeons in Poland

Lactobacillus species play an important role in the host and although they are non-pathogenic, they could act as reservoirs for antibiotic resistance genes, with the potential risk of transfer to other bacteria inhabiting the gastrointestinal tract. The aim of this study was to identify Lactobacillus species derived from feces of domesticated pigeons and to characterize their phenotypic and genotypic antimicrobial resistance (AMR) profiles. A total of 57 Lactobacillus isolates were classified into six species using the MALDI-TOF technique and 16S rDNA restriction analysis. Strains of L. ingluviei (31%), L. salivarius (28%) and L. agilis (23%) were the dominant species isolated. Determination of antimicrobial susceptibility by the microdilution broth method showed widespread resistance to kanamycin (89%), tetracycline (84%), streptomycin (63%), and enrofloxacin (37%). Less than 30% of the isolates were resistant to erythromycin, lincosamides, gentamycin, chloramphenicol and vancomycin. Over half (51%) of the lactobacilli were classified as multidrug resistant. Tet genes were detected in 79% of isolates; the lnuA, cat, ermB, ermC, ant(6)-Ia, ant(4')-Ia, and int-Tn genes were found at a lower frequency. Sequence analysis of the quinolone resistance-determining region (QRDR)of the gyrA gene showed that fluoroquinolone resistance in lactobacilli was the result of a mutation that lead to a change in the amino acid sequence (Ser83→Tyr/Leu/Phe). Domesticated pigeons could be a reservoir for AMR Lactobacillus strains and AMR genes.

Avian influenza virus transmission is suppressed in chickens fed Lactobacillus paracasei expressing the 3D8 single-chain variable fragment protein

The 3D8 single-chain variable fragment (scFv) is a mini-antibody sequence with independent nuclease activity that shows antiviral effects against all types of viruses in chickens and mice. In this study, chickens were treated daily with an oral dose of 10⁹ CFU Lactobacillus paracasei (L. paracasei) expressing either a secreted or anchored 3D8 scFv for three weeks. After L. paracasei administration, the chickens were challenged with avian influenza virus (AIV). From each experimental group, three chickens were directly infected with 100 µL of 10^7.5 EID₅₀/mL H9N2 AIV and seven chickens were indirectly challenged through contact transmission. oropharyngeal and cloacal swab samples were collected at 3, 5, 7, and 9 days post-inoculation (dpi) from AIV-challenged chickens, AIV Shedding titres were measured by quantitative real-time PCR. Contact transmission in the chickens that were fed 3D8 scFv-secreting L. paracasei showed a significant reduction in viral shedding when compared with other groups. These results suggest that L. paracasei secreting 3D8 provides a basis for the development of ingestible antiviral probiotics with activity against AIV.

Effective therapeutic regimens in two South Asian countries with high resistance to major Helicobacter pylori antibiotics

Background

Nepal and Bangladesh have a high prevalence of Helicobacter pylori with high resistance rates to clarithromycin, metronidazole, and levofloxacin. Here, we evaluated the susceptibility and genetic mutations of 5 alternative antibiotics against isolates from both countries to obtain an effective treatment regimen for H. pylori eradication.

Methods

We used the agar dilution method to determine the minimal inhibitory concentration of 5 alternative antibiotics against 42 strains from Nepal and 56 from Bangladesh and performed whole genome mutation analysis.

Results

No resistance to furazolidone or rifabutin and a high susceptibility of sitafloxacin (95.2% in Nepal and 98.2% in Bangladesh) were observed. In contrast, resistance to rifaximin (52.4% in Nepal and 64.3% in Bangladesh) was high. Moreover, resistance to garenoxacin was higher in Bangladesh (51.6%) than in Nepal (28.6%, P = 0.041), most likely due to its correlation with levofloxacin resistance (P = 0.03). Garenoxacin and rifaximin were significantly correlated in Bangladesh (P = 0.014) and occurred together with all sitafloxacin-resistant strains. Mutations of gyrA could play a significant role in garenoxacin resistance, and double mutations of A87 and D91 were associated with sitafloxacin resistance. Analysis of the rpoB gene demonstrated well-known mutations, such as V657I, and several novel mutations, including I2619V, V2592 L, T2537A, and F2538 L.

Conclusions

Rifabutin can be cautiously implemented as therapy for H. pylori infection due to its interaction with the tuberculosis endemic in Bangladesh. The high susceptibility of furazolidone and sitafloxacin suggests their possible future application in Nepal and Bangladesh.

Identification and antibiotic susceptibility of lactobacilli isolated from turkeys

Background

The aim of this study was to identify Lactobacillus isolates derived from turkeys from six Polish farms and to characterize their phenotypic and genotypic antibiotic resistance profiles.

Results

Among 62 isolates identified by MALDI-TOF mass spectrometry and restriction analysis of 16S rDNA, the dominant species was L. salivarius (35%), followed by L. crispatus (21%), L. ingluviei (14.5%) and L. johnsonii (10%). A high prevalence of resistance to tetracycline (68% resistant isolates), lincomycin (64.5%) and enrofloxacin (60%) among the lactobacilli tested was observed. Fewer than 50% isolates were resistant to ampicillin (47%), erythromycin (45%), streptomycin (31%), chloramphenicol (29%) and gentamicin (10%). As many as 64,5% of the isolates showed multidrug resistance. High MIC values for ampicillin (≥64 μg/ml) were usually accompanied by elevated MICs for cephalosporins (≥16 μg/ml) and high MICs for tiamulin, i.e. ≥32 μg/ml, were noted in most of the turkey lactobacilli (61%). The occurrence of resistance genes was associated with phenotypic resistance, with the exception of five phenotypically susceptible isolates that contained the tetM, tetL, ermC, ermB or cat genes. The most frequently identified were ermB (45% isolates), tetL (40%), tetW (37%) and tetM (29%), and the occurrence of lnuA (18%), cat (10%), ermC (6%), ant(6)-Ia (5%) and aadE (5%) was less frequent. The mechanism of ampicillin resistance has not been elucidated, but the results of nitrocefin test confirmed that it is not involved in the production of beta-lactamases.

Conclusions

The high rate of antibiotic resistance observed in this study indicates the need to implement the principles of rational use of antibiotics in poultry. The presence of transmissible resistant genes in lactobacilli may contribute to the development of antibiotic resistant pathogenic strains that pose a threat to both poultry and consumers. The results of these studies may be useful for committees providing guidance on antibiotic susceptibility of microorganisms in order to revise and supplement current microbiological cut-offs values within the genus Lactobacillus.

Electronic supplementary material

The online version of this article (10.1186/s12866-018-1269-6) contains supplementary material, which is available to authorized users.

Assessment of antibiotic susceptibility in Lactobacillus isolates from chickens

BACKGROUND

The aim of this study was to determine the susceptibility of 88 Lactobacillus isolates derived from chickens to antibiotic substances and to detect drug-resistance genes.

RESULTS

The minimal inhibitory concentration of 13 antimicrobial substances was determined by the broth microdilution method, and resistance genes were detected by PCR. We recorded a high prevalence of resistance to tiamulin (90% resistant isolates), tetracyclines (74%) and lincomycin (70%), and a moderately high frequency of resistance to enrofloxacin (48%), macrolides (42%), aminoglycosides (12.5-31%), ampicillin (26%) and chloramphenicol (23%). Multi-drug resistance was observed in 79.5% of isolates. The presence of resistance genes was generally correlated with phenotypic resistance, but some molecular determinants were also recorded in susceptible isolates. Among tetracycline resistance genes, the most frequently identified was tetW (45% isolates), followed by tetM (26%) and tetL (24%). The ermB, ermC and lnuA genes, associated with resistance to macrolides and lincosamides, were observed in 39, 12 and 39% of isolates, respectively. Among genes determining resistance to aminoglycoside antibiotics, we identified ant(6)-Ia (10% of isolates), aac(6')-Ie-aph(2')-Ia (8%), aph(2″)-Ic (6%) and aadE (4.5%). The cat gene was present in 32 isolates, including 8 of 20 found to be resistant to chloramphenicol. Two genes encoding efflux pumps were identified-the acrA gene was present in all isolates tested, and 10 of 79 lactobacilli determined to be phenotypically resistant to tiamulin contained the lsaE gene. We were unable to explain the resistance mechanism of Lactobacillus isolates to ampicillin, but showed that it did not involve the production of β-lactamases.

CONCLUSIONS

Our findings indicate that intestinal lactobacilli should be considered a reservoir of resistance genes and that antibiotics must be used prudently in poultry production. The data derived from this study can be used as a basis for reviewing current microbiological breakpoints for categorization of susceptible and resistant strains within the genus Lactobacillus.