Sarcocystis neurona Transmission from Opossums to Marine Mammals in the Pacific Northwest

EcoHealth - Increasing reports of marine mammal deaths have been attributed to the parasite Sarcocystis neurona. Infected opossums, the only known definitive hosts, shed S. neurona sporocysts in...     

Antimicrobial Resistance of Enterococcus Species Isolated from Produce

The purpose of this study was to characterize the antibiotic resistance profiles of Enterococcus species isolated from fresh produce harvested in the southwestern United States. Among the 185 Enterococcus isolates obtained, 97 (52%) were Enterococcus faecium, 38 (21%) were Enterococcus faecalis, and 50 (27%) were other Enterococcus species. Of human clinical importance, E. faecium strains had a much higher prevalence of resistance to ciprofloxacin, tetracycline, and nitrofurantoin than E. faecalis. E. faecalis strains had a low prevalence of resistance to antibiotics used to treat E. faecalis infections of both clinical and of agricultural relevance, excluding its intrinsic resistance patterns. Thirty-four percent of the isolates had multiple-drug-resistance patterns, excluding intrinsic resistance. Data on the prevalence and types of antibiotic resistance in Enterococcus species isolated from fresh produce may be used to describe baseline antibiotic susceptibility profiles associated with Enterococcus spp. isolated from the environment. The data collected may also help elucidate the role of foods in the transmission of antibiotic-resistant strains to human populations.     

Antibiotic Resistance in Bacteria Isolated from the Deep Terrestrial Subsurface

Various natural environments have been examined for the presence of antibiotic-resistant bacteria and/or novel resistance mechanisms, but little is known about resistance in the terrestrial deep subsurface. This study examined two deep environments that differ in their known period of isolation from surface environments and the bacteria therein. One hundred fifty-four strains of bacteria were isolated from sediments located 170–259 m below land surface at the US Department of Energy Savannah River Site (SRS) in South Carolina and Hanford Site (HS) in Washington. Analyses of 16S rRNA gene sequences showed that both sets of strains were phylogenetically diverse and could be assigned to several genera in three to four phyla. All of the strains were screened for resistance to 13 antibiotics by plating on selective media and 90% were resistant to at least one antibiotic. Eighty-six percent of the SRS and 62% of the HS strains were resistant to more than one antibiotic. Resistance to nalidixic acid, mupirocin, or ampicillin was noted most frequently. The results indicate that antibiotic resistance is common among subsurface bacteria. The somewhat higher frequencies of resistance and multiple resistance at the SRS may, in part, be due to recent surface influence, such as exposure to antibiotics used in agriculture. However, the HS strains have never been exposed to anthropogenic antibiotics but still had a reasonably high frequency of resistance. Given their long period of isolation from surface influences, it is possible that they possess some novel antibiotic resistance genes and/or resistance mechanisms. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Combined Antimicrobial Resistance in Enterococcus faecium Isolated from Chickens

Nineteen E. faecium strains isolated from chicken caecum samples, collected in slaughterhouses and highly resistant to vancomycin or gentamicin, were coresistant to erythromycin, and/or tetracyclines, and/or streptogramins, and/or avilamycin. Multiple antibiotic resistance was related to the presence in various combinations of aac(6′)-aph(2"), erm(B), emtA, mef(A), tet(L), tet(M), and vanA genes.     

具抑菌活性海洋微生物的筛选

从上海郊区海域采集的海水、海泥样中分离出193株海洋细菌,对其进行抑菌活性菌株的筛选。对分离出的菌株分别利用琼脂块法和管碟法进行初筛和复筛,结果显示有29株海洋细菌具有抑菌活性,占总分离菌株的15%,其中抑菌能力较强的G4抑菌谱较广,同时能抑制革兰氏阳性和阴性指示菌。     

Basic Antibiotic Resistance of Bacteria Isolated from Different Biotopes

Microbiology - Soil is not only a habitat of antibiotic-resistant microorganisms and a natural source of antibiotic resistance genes, but also an environment in which clinical determinants of...     

Resistance to Antimicrobial Agents in Lactobacilli Isolated from Caper Fermentations

A collection of lactobacilli comprising species of Lactobacillus plantarum (43 isolates), Lactobacillus brevis (9 isolates) and Lactobacillus fermentum (6 isolates) obtained from spontaneous fermentations of capers (the fruits of Capparis spinosa) were investigated for resistance to antimicrobial agents. All isolates were resistant to vancomycin and teicoplanin (MIC > 16 μg/ml). Resistance to ciprofloxacin (MIC > 2 μg/ml) was detected in all isolates of L. brevis and L. fermentum as well as in most isolates of L. plantarum, whilst resistance to levofloxacin showed a much lower incidence. Among L. plantarum and L. brevis isolates, low levels of resistance to tetracycline and/or nitrofurantoin were detected. Higher resistance levels were also detected in some isolates. Resistance to penicillin and rifampicin were also detected among L. plantarum isolates. All isolates were sensitive to ampicillin, erythromycin, chloramphenicol, gentamicin, streptomycin, and quinupristin/dalfopristin.     

Production of Antimicrobial Substances by Bacteria Isolated from Fermented Table Olives

Summary The production of antimicrobial substances was studied among 195 bacterial isolates from retail table olives. A total 86 isolates tested positive, and they clustered in 10 groups according to their inhibitory spectra. Many isolates (38.37%) produced strong inhibition against all bacteria tested (Listeria innocua, Lactococcus lactis, Bacillus cereus, B. megaterium, Staphylococcus aureus, Micrococcus luteus, Enterococcus faecalis, and Escherichia coli). The selected bacterial isolates were Gram-positive bacteria with rod morphology (62.67%), short rods (26.65%) or cocci (10.67%). Isolates producing antimicrobial substances may be useful as starters to enhance control of table olive fermentation and improve the safety of retail table olives.     

High Prevalence of Multidrug-Tolerant Bacteria and Associated Antimicrobial Resistance Genes Isolated from Ornamental Fish and Their Carriage Water

Background

Antimicrobials are used to directly control bacterial infections in pet (ornamental) fish and are routinely added to the water these fish are shipped in to suppress the growth of potential pathogens during transport.

Methodology/Principal Findings

To assess the potential effects of this sustained selection pressure, 127 Aeromonas spp. isolated from warm and cold water ornamental fish species were screened for tolerance to 34 antimicrobials. Representative isolates were also examined for the presence of 54 resistance genes by a combination of miniaturized microarray and conventional PCR. Forty-seven of 94 Aeromonas spp. isolates recovered from tropical ornamental fish and their carriage water were tolerant to ≥15 antibiotics, representing seven or more different classes of antimicrobial. The quinolone and fluoroquinolone resistance gene, qnrS2, was detected at high frequency (37% tested recent isolates were positive by PCR). Class 1 integrons, IncA/C broad host range plasmids and a range of other antibiotic resistance genes, including floR, bla _TEM−1, tet(A), tet(D), tet(E), qacE2, sul1, and a number of different dihydrofolate reductase and aminoglycoside transferase coding genes were also detected in carriage water samples and bacterial isolates.

Conclusions

These data suggest that ornamental fish and their carriage water act as a reservoir for both multi-resistant bacteria and resistance genes.     

Antimicrobial Activity of Bacteria Isolated from the Millipedes Nedyopus dawydoffiae and Orthomorpha sp.

Microbiology - From the intestines of millipedes of the species Nedyopus dawydoffiae and Orthomorpha sp. (class Diplopoda) and from their food substrates (plant residues), 72 bacterial strains...     

Uterine Microbiology and Antimicrobial Susceptibility in Isolated Bacteria from Mares with Fertility Problems

Uterine microbiology and antimicrobial susceptibility was investigated in 239 mares with fertility problems in a prospective study in Sweden. Uterine swab samples were collected with double guarded swabs and transported overnight before being cultured. The Minimum Inhibitory Concentrations (MIC) was determined for a panel of antimicrobials. From 152 of the 239 mares at least one bacterial species was isolated, most frequently E. coli (104 isolates), β -haemolytic streptococci (31) and fungi (16). β -haemolytic streptococci were more frequently (p < 0.01) associated with clinical endometritis than with repeat breeding. The opposite was true for E. coli (p < 0.01). Among β -haemolytic streptococcal isolates some resistance was noted for 4 of 11 tested antibiotics, however, all isolates were susceptible to the widely used penicillin G. Among E. coli isolates enrofloxacin was the only of the 10 tested antibiotics for which no resistance was noted. Resistance was most commonly noted to cephalothin (39% of the isolates), streptomycin (22%), trimethoprim/sulphamethoxazole (15%) and ampicillin (11%). In conclusion, we show that both E. coli and β -haemolytic streptococci are frequently associated with fertility problems in mares and that antimicrobial resistance is a common feature of E. coli but also recognised for β -haemolytic streptococcal uterine isolates.     

The Incidence of Antibiotic Resistance among Coliform Bacteria Isolated from Food

Three-hundred-and-seventy-eight strains of coliform bacteria were isolated from specimens of commonly sold milk and food products. Klebsiella and Enterobacter spp. were predominating. Resistance to sulphonamides, streptomycin, and chloramphenicol occurred in only 5, 1, and 2 strains, respectively. No tetracycline-resistant strains were found. Two-hundred-and-two strains (54 %) were resistant to ampicillin. In genetic crosses with a sensitive strain of E. coli Κ 12 W 3132 transmissible R factors could not be demonstrated in any of the resistant coliform strains. It is concluded that food is not a significant source of antibiotic resistant enteric bacteria. It may, however, be suggested that food is a source of potentially pathogenic gram-negative bacteria which points out the importance of strict hygienic surveillance of food production.     

Bacteriophages Isolated from Chicken Meat and the Horizontal Transfer of Antimicrobial Resistance Genes

Antimicrobial resistance in microbes poses a global and increasing threat to public health. The horizontal transfer of antimicrobial resistance genes was thought to be due largely to conjugative plasmids or transposons, with only a minor part being played by transduction through bacteriophages. However, whole-genome sequencing has recently shown that the latter mechanism could be highly important in the exchange of antimicrobial resistance genes between microorganisms and environments. The transfer of antimicrobial resistance genes by phages could underlie the origin of resistant bacteria found in food. We show that chicken meat carries a number of phages capable of transferring antimicrobial resistance. Of 243 phages randomly isolated from chicken meat, about a quarter (24.7%) were able to transduce resistance to one or more of the five antimicrobials tested into Escherichia coli ATCC 13706 (DSM 12242). Resistance to kanamycin was transduced the most often, followed by that to chloramphenicol, with four phages transducing tetracycline resistance and three transducing ampicillin resistance. Phages able to transduce antimicrobial resistance were isolated from 44% of the samples of chicken meat that we tested. The statistically significant (P = 0.01) relationship between the presence of phages transducing kanamycin resistance and E. coli isolates resistant to this antibiotic suggests that transduction may be an important mechanism for transferring kanamycin resistance to E. coli. It appears that the transduction of resistance to certain antimicrobials, e.g., kanamycin, not only is widely distributed in E. coli isolates found on meat but also could represent a major mechanism for resistance transfer. The result is of high importance for animal and human health.     

具有抑菌活性的海洋细菌的分离与鉴定

分离并筛选具有抑菌活性的海洋细菌对于开发和利用海洋微生物具有重要意义,该研究从6份海泥样品中共分离到78株海洋细菌,以6种细菌作为敏感指示菌,采用覆盖技术对分离菌株进行拮抗试验,17株海洋细菌具有抑菌活性,对其中2株具有较强抑菌活性的海洋细菌进行革兰氏染色,耐盐试验,运动性观察,过氧化氢酶测定,明胶液化试验,硫化氢产生试验,石蕊牛奶试验,糖类发酵,硝酸盐还原等特性分析,依据《伯杰氏细菌鉴定手册》进行分类鉴定,它们分别应归属为气单孢菌属（Aeromonas sp.）和假单孢菌属（Pseudomonas sp.）。     

Antibiotic Resistance of Bacteria Isolated from the Internal Organs of Edible Snow Crabs

Antibiotic resistance and microbiota within edible snow crabs are important for the Chionoecetes (snow crab) fishing industry. We investigated these parameters using culture methods and antibiotic susceptibility tests with six internal organs from three species of Chionoecetes. Each sample revealed many unexpected microbial species within Chionoecetes internal organs. On the basis of 16S rRNA sequence analysis of 381 isolates, the most abundant genera identified in Chionoecetes opilio were Acinetobacter spp. (24%), Bacillus spp. (4%), Pseudomonas spp. (34%), Stenotrophomonas spp. (28%), and Agreia spp. (11%). In Chionoecetes sp. crabs, Acinetobacter spp. (23%), Bacillus spp. (12%), and Psychrobacter spp. (20%) were most prevalent, while Agreia spp. (11%), Bacillus spp. (31%), Microbacterium spp. (10%), Rhodococcus spp. (12%), and Agrococcus spp. (6%) were most abundant in C. japonicus. Our antibiotic resistance test found resistance to all nine antibiotics tested in 19, 14, and two of the isolates from C. opilio, Chionoecetes sp., and, C. japonicus respectively. Our results are the first to show that microbes with antibiotic resistance are widely distributed throughout the internal organs of natural snow crabs.     

圈养大熊猫肠道微生物分离、鉴定及细菌耐药性研究

对中国卧龙自然保护区大熊猫研究中心-碧峰峡基地64只大熊猫分别采取粪样,用选择性培养基分离大肠杆菌、沙门氏菌,根据形态特征及16S rDNA序列对菌株进行鉴定;用PDA培养基分离真菌,真菌通用引物ITS4、ITS5进行扩增鉴定。采用K-B法(CLSI)药敏试验测试大肠杆菌和沙门氏菌对18种药敏纸片的耐药性。形态学与rDNA-ITS序列鉴定表明,共分离到真菌19株,鉴定为8个属。分离出大肠杆菌88株,沙门氏菌47株;大肠杆菌对各抗生素的耐药率为0%~35.22%,耐药率为TET(35.22%)、AML(12.50%)、S3(12.50%),共产生17种耐药谱,其中TET、AML-TET谱型占优势;沙门氏菌对各抗生素的耐药率为0%~42.55%,耐药率为TET(42.55%)、AML(40.43%)、S3(38.30%),也产生了17种耐药谱,AML和AML-TET谱型占优势。通过对细菌和真菌的分离鉴定以及细菌的耐药性试验,了解大熊猫肠道微生物与不同个体的关系,为研究大熊猫的营养及消化等奠定基础,对预防和诊断大熊猫肠道疾病,提高大熊猫的存活率提供依据。     

Investigation of Antimicrobial Resistance in Escherichia coli and Enterococci Isolated from Tibetan Pigs

Objectives

This study investigated the antimicrobial resistance of Escherichia coli and enterococci isolated from free-ranging Tibetan pigs in Tibet, China, and analyzed the influence of free-ranging husbandry on antimicrobial resistance.

Methods

A total of 232 fecal samples were collected from Tibetan pigs, and the disk diffusion method was used to examine their antimicrobial resistance. Broth microdilution and agar dilution methods were used to determine minimum inhibitory concentrations for antimicrobial agents for which disks were not commercially available.

Results

A total of 129 E. coli isolates and 84 Enterococcus isolates were recovered from the fecal samples. All E. coli isolates were susceptible to amoxicillin/clavulanic acid, and 40.4% were resistant to tetracycline. A small number of isolates were resistant to florfenicol (27.9%), ampicillin (27.9%), sulfamethoxazole/trimethoprim (19.4%), nalidixic acid (19.4%), streptomycin (16.2%) and ceftiofur (10.9%), and very low resistance rates to ciprofloxacin (7.8%), gentamicin (6.9%), and spectinomycin (2.3%) were observed in E. coli. All Enterococcus isolates, including E. faecium, E. faecalis, E. hirae, and E. mundtii, were susceptible to amoxicillin/clavulanic acid and vancomycin, but showed high frequencies of resistance to oxacillin (92.8%), clindamycin (82.1%), tetracycline (64.3%), and erythromycin (48.8%). Resistance rates to florfenicol (17.9%), penicillin (6.0%), ciprofloxacin (3.6%), levofloxacin (1.2%), and ampicillin (1.2%) were low. Only one high-level streptomycin resistant E. faecium isolate and one high-level gentamicin resistant E. faecium isolate were observed. Approximately 20% and 70% of E. coli and Enterococcus isolates, respectively, were defined as multidrug-resistant.

Conclusions

In this study, E. coli and Enterococcus isolated from free-ranging Tibetan pigs showed relatively lower resistance rates than those in other areas of China, where more intensive farming practices are used. These results also revealed that free-range husbandry and absence of antibiotic use could decrease the occurrence of antimicrobial resistance to some extent.     

Isolation,Biochemical and Molecular Identification,and In-Vitro Antimicrobial Resistance Patterns of Bacteria Isolated from Bubaline Subclinical Mastitis in South India

Buffaloes are the second largest source of milk. Mastitis is a major impediment for milk production, but not much information is available about bubaline mastitis, especially subclinical mastitis. The aim of this study was to (a) investigate the application of various tests for the diagnosis of bubaline subclinical mastitis, (b) identify the major bacteria associated with it, and (c) evaluate the antibiotic resistance pattern of the bacteria. To this end, 190 quarter milk samples were collected from 57 domesticated dairy buffaloes from organized (64 samples) and unorganized (126 samples) sectors. Of these, 48.4%, 40.0%, 45.8%, 61.1%, and 61.6% were positive for subclinical mastitis by somatic cell count, electrical conductivity, California mastitis test, bromothymol blue test, and N-acetyl glucosaminidase test, respectively. As compared to the gold standard of somatic cell count, California mastitis test performed the best. However, a combination of the two methods was found to be the best option. Microbiological evaluation, both by biochemical methods as well as by monoplex and multiplex polymerase chain reaction, revealed that coagulase-negative staphylococci were the most predominant (64.8%) bacteria, followed by streptococci (18.1%), Escherichia coli (9.8%) and Staphylococcus aureus (7.3%). Most of the pathogens were resistant to multiple antibiotics, especially to β-lactam antibiotics. We propose that California mastitis test be combined with somatic cell count for diagnosis of subclinical mastitis in domestic dairy buffaloes. Further, our results reveal high resistance of the associated bacteria to the β-lactam class of antibiotics, and a possible major role of coagulase-negative staphylococci in causing the disease in India.     

The Biodiversity and Antimicrobial Activity of Bacteria Isolated from the Bottom Sediments of the Chukchi Sea

Russian Journal of Marine Biology - Two hundred and forty eight strains of heterotrophic microorganisms were isolated from bottom sediments of the Chukchi Sea. A 16S rRNA gene sequence analysis was...     

Isolation and Analysis of Bacteria with Antimicrobial Activities from the Marine Sponge Haliclona simulans Collected from Irish Waters

Samples of the marine sponge Haliclona simulans were collected from Irish coastal waters, and bacteria were isolated from these samples. Phylogenetic analyses of the cultured isolates showed that four different bacterial phyla were represented; Bacteriodetes, Actinobacteria, Proteobacteria, and Firmicutes. The sponge bacterial isolates were assayed for the production of antimicrobial substances, and biological activities against Gram-positive and Gram-negative bacteria and fungi were demonstrated, with 50% of isolates showing antimicrobial activity against at least one of the test strains. Further testing showed that the antimicrobial activities extended to the important pathogens Pseudomonas aeruginosa, Clostridium difficile, multi-drug-resistant Staphylococcus aureus, and pathogenic yeast strains. The Actinomycetes were numerically the most abundant producers of antimicrobial activities, although activities were also noted from Bacilli and Pseudovibrio isolates. Surveys for the presence of potential antibiotic encoding polyketide synthase and nonribosomal peptide synthetase genes also revealed that genes for the biosynthesis of these secondary metabolites were present in most bacterial phyla but were particularly prevalent among the Actinobacteria and Proteobacteria. This study demonstrates that the culturable fraction of bacteria from the sponge H. simulans is diverse and appears to possess much potential as a source for the discovery of new medically relevant biological active agents.