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Abdullahi IN, Juárez-Fernández G, Höfle Ú, Cardona-Cabrera T, Mínguez D, Pineda-Pampliega J, Lozano C, Zarazaga M, Torres C. Nasotracheal Microbiota of Nestlings of Parent White storks with Different Foraging Habits in Spain. ECOHEALTH 2023; 20:105-121. [PMID: 37060390 DOI: 10.1007/s10393-023-01626-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 02/11/2023] [Indexed: 06/11/2023]
Abstract
Migratory storks could be vectors of transmission of bacteria of public health concern mediated by the colonization, persistence and excretion of such bacteria. This study aims to determine genera/species diversity, prevalence, and co-colonization indices of bacteria obtained from tracheal (T) and nasal (N) samples from storks in relation to exposure to point sources through foraging. One-hundred and thirty-six samples from 87 nestlings of colonies of parent white storks with different foraging habits (natural habitat and landfills) were obtained (84 T-samples and 52 N-samples) and processed. Morphologically distinct colonies (up to 12/sample) were randomly selected and identified by MALDI-TOF-MS. About 87.2% of the total 806 isolates recovered were identified: 398 from T-samples (56.6%) and 305 from N-samples (43.4%). Among identified isolates, 17 genera and 46 species of Gram-positive and Gram-negative bacteria were detected, Staphylococcus (58.0%) and Enterococcus (20.5%) being the most prevalent genera. S. sciuri was the most prevalent species from T (36.7%) and N (34.4%) cavities of total isolates, followed by E. faecalis (11.1% each from T and N), and S. aureus [T (6.5%), N (13.4%)]. Of N-samples, E. faecium was significantly associated with nestlings of parent storks foraging in landfills (p = 0.018). S. sciuri (p = 0.0034) and M. caseolyticus (p = 0.032) from T-samples were significantly higher among nestlings of parent storks foraging in natural habitats. More than 80% of bacterial species in the T and N cavities showed 1-10% co-colonization indices with one another, but few had ≥ 40% indices. S. sciuri and E. faecalis were the most frequent species identified in the stork nestlings. Moreover, they were highly colonized by other diverse and potentially pathogenic bacteria. Thus, storks could be sentinels of point sources and vehicles of bacterial transmission across the "One Health" ecosystems.
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Affiliation(s)
- Idris Nasir Abdullahi
- OneHealth-UR Research Group, Area of Biochemistry and Molecular Biology, University of La Rioja, Logroño, Spain
| | - Guillermo Juárez-Fernández
- OneHealth-UR Research Group, Area of Biochemistry and Molecular Biology, University of La Rioja, Logroño, Spain
| | - Úrsula Höfle
- SaBio (Health and Biotechnology) Research Group, Game and Wildlife Research Institute (CSIC-UCLM-JCCM), Ciudad Real, Spain
| | - Teresa Cardona-Cabrera
- SaBio (Health and Biotechnology) Research Group, Game and Wildlife Research Institute (CSIC-UCLM-JCCM), Ciudad Real, Spain
| | - David Mínguez
- OneHealth-UR Research Group, Area of Biochemistry and Molecular Biology, University of La Rioja, Logroño, Spain
| | - Javier Pineda-Pampliega
- Department of Biology, Lund University, Lund, Sweden
- Department of Biodiversity, Ecology and Evolution, Faculty of Biology, Complutense University of Madrid, Madrid, Spain
| | - Carmen Lozano
- OneHealth-UR Research Group, Area of Biochemistry and Molecular Biology, University of La Rioja, Logroño, Spain
| | - Myriam Zarazaga
- OneHealth-UR Research Group, Area of Biochemistry and Molecular Biology, University of La Rioja, Logroño, Spain
| | - Carmen Torres
- OneHealth-UR Research Group, Area of Biochemistry and Molecular Biology, University of La Rioja, Logroño, Spain.
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Zhang Y, Min S, Sun Y, Ye J, Zhou Z, Li H. Characteristics of population structure, antimicrobial resistance, virulence factors, and morphology of methicillin-resistant Macrococcus caseolyticus in global clades. BMC Microbiol 2022; 22:266. [PMID: 36335318 PMCID: PMC9636676 DOI: 10.1186/s12866-022-02679-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 10/25/2022] [Indexed: 11/06/2022] Open
Abstract
Macrococcus caseolyticus is an opportunistic pathogen that is frequently isolated from dairy products and veterinary infections. Recent studies have reported the possibility of methicillin resistance that be transferred among staphylococcal species in foods. The present study examined the population structure, antimicrobial resistance, virulence factors, and morphology of methicillin-resistant M. caseolyticus by investigation of 94 genomes derived from both isolates in beef (n = 7) and pork (n = 2) at Shanghai and those deposited in public domain (n = 85). Phylogenetically, M. caseolyticus were divided into four clades, which each consisted of genomes isolated from continent of European countries (82.4%, n = 78), Asian countries (11.3%, n = 10), United States (4.1%, n = 4), Australia (1%, n = 1), and Sudan (1%, n = 1). The M. caseolyticus isolated from present study formed a genetically distinguished clade, which was characterized by novel alleles in the traditional 7-gene MLST scheme. Furthermore, we identified 24 AMR genes that were associated with 10 classes of antimicrobial agents in M. caseolyticus. Most AMR genes were carried by dominant plasmids such as rep7a, rep22 and repUS56. The genomes in the global clades carried significantly less AMR genes (p < 0.05) and more virulence factors (p < 0.001) than present clade. Virulence factors were detected in methicillin resistant M. caseolyticus including genes coding hemolysin, adherence, biofilm formation, exotoxin, and capsule that associated to human health and infection. Finally, as the close relative of the genus Staphylococcus, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were performed for morphological comparison that M. caseolyticus has a larger diameter and thicker cell wall compared with S. aureus ATCC 25,923. Taken together, our study suggested that M. caseolyticus mediating divergent antimicrobial resistance and virulence factors could serve as the vector for methicillin resistance habitats in foodborne microorganisms. • The global lineage of M. caseolyticus strains were divided into four clades from A to D. • MLST typing revealed novel alleles in M. caseolyticus strains isolated in China. • Global clades carried significantly less AMR genes and more virulence factors than present isolates. • As the close relative of the genus Staphylococcus, Macrococcus caseolyticus has a larger diameter and thicker cell wall compared with S.aureus ATCC 25923. • Macrococcus caseolyticus may serve as a vector for methicillin resistance habitats in foodborne microorganisms.
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Klempt M, Franz CMAP, Hammer P. Characterization of coagulase-negative staphylococci and macrococci isolated from cheese in Germany. J Dairy Sci 2022; 105:7951-7958. [PMID: 35965117 DOI: 10.3168/jds.2022-21941] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 05/23/2022] [Indexed: 11/19/2022]
Abstract
Cheese, especially ripened varieties, harbor a very complex and heterogeneous microbiota. In addition to the desired microorganisms (starter cultures) added during cheese production, potentially harmful bacteria may also enter the production chain. Regarding the latter, the focus of this study was on coagulase-negative staphylococci (CNS) and Macrococcus caseolyticus. Both are known to harbor a variety of genes coding for antibiotic resistance, including mecA, mecB, mecC, and mecD. Coagulase-negative staphylococci or macrococci carrying such genes or other virulence factors should not be present in cheese. Cheese samples (101 in total) were collected from retail sources. Coagulase-negative staphylococci and M. caseolyticus were isolated utilizing selective agars, and species were identified by phenotypical tests and partial sequencing of the sodA gene. The results allowed identification of 53 CNS strains and 19 M. caseolyticus strains. Among the CNS, 11 isolates of Staphylococcus saprophyticus and one Staphylococcus epidermidis isolate were obtained. Both species are potential human pathogens and may thus adversely affect the safety of these food products. Screening for antimicrobial resistance was performed by application of disc diffusion tests, a gradient strip-test, and 14 different PCR tests. Evidence for methicillin resistance (by either positive disc diffusion assay for cefoxitin or by mec PCR) was found in CNS isolates and M. caseolyticus (9 isolates each). Regarding other virulence factors, no genetic determinants for coagulase or the most common staphylococcal enterotoxins sea, seb, sec, sed, and see were detected in any of the CNS or M. caseolyticus isolates by PCR testing. In conclusion, the presence of facultatively pathogenic CNS and carriers of genes for antibiotic resistance in both groups of microorganisms, especially mec genes, and the respective food safety issues need further evaluation and surveillance.
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Affiliation(s)
- M Klempt
- Department of Microbiology and Biotechnology, Max Rubner-Institute, Federal Research Institute of Nutrition and Food, 24103 Kiel, Germany
| | - C M A P Franz
- Department of Microbiology and Biotechnology, Max Rubner-Institute, Federal Research Institute of Nutrition and Food, 24103 Kiel, Germany
| | - P Hammer
- Department of Microbiology and Biotechnology, Max Rubner-Institute, Federal Research Institute of Nutrition and Food, 24103 Kiel, Germany.
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Keller JE, Schwendener S, Overesch G, Perreten V. Macrococcus armenti sp. nov., a novel bacterium isolated from the skin and nasal cavities of healthy pigs and calves. Int J Syst Evol Microbiol 2022; 72. [DOI: 10.1099/ijsem.0.005245] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Gram-positive coccoid bacteria were isolated from the nasal cavities of pigs and calves as well as from axillar and inguinal skin regions of pigs. Phylogenetic analysis of seven strains based on complete genome, 16S rRNA, hsp60, dnaJ, rpoB and sodA gene sequences and MALDI-TOF MS profiles revealed that they belonged to the genus
Macrococcus
with the closest relatedness to
Macrococcus canis
,
Macrococcus caseolyticus
subsp.
caseolyticus
and
Macrococcus caseolyticus
subsp.
hominis
. DNA relatedness of the type strain JEK37T with the type strains of
M. canis
,
M. caseolyticus
subsp.
caseolyticus
and
M. caseolyticus
subsp.
hominis
was 23.4, 23.1 and 23.0 % by digital DNA–DNA hybridization and 80.39, 80.45 and 80.87 % by average nucleotide identity (ANI) calculations, confirming that they do not belong to the same species. The DNA G+C content of JEK37T was 35.65 mol%. The novel strains can be differentiated from
M. canis
KM 45013T by the ability to fermentate d-ribose and by the absence of DNAase production and haemolysis, from
M. caseolyticus
subsp.
caseolyticus
CCUG 15606T by the ability to fermentate sucrose and from both species by the inability to grow in 9 and 12% NaCl. They differ from M. caseolyiticus subsp. hominis by the presence of α-glucosidase. The most common fatty acids of JEK37T were C14 : 0, C18 : 1 ω9c and C18 : 0. Known polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, aminolipid, aminoglycolipid, aminophospholipid, glycolipid and phospholipid. Cell-wall peptidoglycan of JEK37T was of type A3α l-Lys–Gly2–L-Ser–Gly (similar to A11.3) and the respiratory quinolone was menaquinone 6. Based on their genotypic and chemotaxonomic characteristics, these strains represent a novel species of the genus
Macrococcus
, for which we propose the name Macrococcus armenti sp. nov. The type strain is JEK37T (=DSM 112712T=CCOS 1982T).
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Affiliation(s)
| | - Sybille Schwendener
- Institute of Veterinary Bacteriology, University of Bern, CH-3012, Bern, Switzerland
| | - Gudrun Overesch
- Institute of Veterinary Bacteriology, University of Bern, CH-3012, Bern, Switzerland
| | - Vincent Perreten
- Institute of Veterinary Bacteriology, University of Bern, CH-3012, Bern, Switzerland
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5
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LI ZD, QI FY, LI F. Integrating 16S sequencing and metabolomics study on anti-rheumatic mechanisms against collagen-induced arthritis of Wantong Jingu Tablet. Chin J Nat Med 2022; 20:120-132. [DOI: 10.1016/s1875-5364(21)60080-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Indexed: 11/03/2022]
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Methicillin-resistant Macrococcus canis in a human wound. INFECTION GENETICS AND EVOLUTION 2021; 96:105125. [PMID: 34715385 DOI: 10.1016/j.meegid.2021.105125] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 09/01/2021] [Accepted: 10/22/2021] [Indexed: 11/20/2022]
Abstract
A hemolytic Macrococcus canis strain (LI021) was isolated for the first time from a human skin infection. The complete genome of LI021 consisting of a 2,216,765-bp circular chromosome was obtained by de novo hybrid assembly of Illumina and Oxford Nanopore technology reads. Strain LI021 belonged to the new sequence type ST75 and was resistant to β-lactam antibiotics due to the presence of a methicillin resistance gene mecB. The mecB gene as well as putative hemolysin genes hlgB and hlgC were located on a novel composite pseudo (Ψ) SCCmec island. These findings show that a methicillin-resistant M. canis may be associated with human infection and indicate that this bacterium should be considered by human diagnostic laboratories.
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Ramos GLPA, Vigoder HC, Nascimento JS. Technological Applications of Macrococcus caseolyticus and its Impact on Food Safety. Curr Microbiol 2020; 78:11-16. [PMID: 33165661 DOI: 10.1007/s00284-020-02281-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 10/28/2020] [Indexed: 10/23/2022]
Abstract
Macrococcus spp. are Gram-positive cocci that belong to the Staphylococcaceae family; they are closely related to staphylococci, but, unlike staphylococci, they are not considered as human pathogens. Macrococcus spp. are recognized as relevant veterinary pathogens, and their presence has been reported in food products of animal origin. Macrococcus caseolyticus, the most studied species of the Macrococcus genus, is associated with the development of aroma and flavor in fermented foods and is, thus, used as starter cultures in fermentations. However, certain important issues regarding food safety must be taken into account when employing these microorganisms in fermentations. Recent studies have reported the presence of genes associated with resistance to methicillin and other antibiotics in M. caseolyticus. This can be harmful to human health as these genes can be transferred to other bacteria present in the food, mainly staphylococcal species. This work, therefore, aims to highlight the importance of a more critical view on the presence of macrococci in foods and the possible indirect risks to human health.
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Affiliation(s)
| | - H C Vigoder
- Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro, Rio de Janeiro, Brazil
| | - J S Nascimento
- Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro, Rio de Janeiro, Brazil.
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Methicillin-Resistant Macrococcus bohemicus Encoding a Divergent SCC mecB Element. Antibiotics (Basel) 2020; 9:antibiotics9090590. [PMID: 32927653 PMCID: PMC7560078 DOI: 10.3390/antibiotics9090590] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/02/2020] [Accepted: 09/07/2020] [Indexed: 11/22/2022] Open
Abstract
A methicillin-resistant Macrococcus isolate from canine otitis, H889678/16/1, was whole-genome sequenced using HiSeq technology to identify the species, antimicrobial resistance determinates and their genomic context. H889678/16/1 belonged to the newly described species Macrococcus bohemicus. It encoded mecB within a novel SCCmec element most similar to that of Macrococcus canis KM45013T. This SCCmecH889678/16/1 element also encoded blaZm and fusC, but no other resistance determinates were found in the H889678/16/1 genome. The ccrA and ccrB recombinase genes within SCCmecH889678/16/1 were distinct from those previously described in staphylococci and macrococci and therefore designated here as ccrAm3 and ccrBm3. Our study represents, to the best of our knowledge, the first description of mecB being encoded by M. bohemicus and of methicillin resistance in this species. Furthermore, the SCCmec described here is highly dissimilar to other such elements and encodes novel ccr genes. Our report demonstrates a wider distribution of mecB among Macrococcus species and expands the genomic context in which mecB may be found. The potential for dissemination of mec genes from Macrococcus to related but more pathogenic Staphylococcus species highlights the need to understand the epidemiology of these genes in macrococci.
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10
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Huang Z, Shen Y, Huang X, Qiao M, He RK, Song L. Microbial diversity of representative traditional fermented sausages in different regions of China. J Appl Microbiol 2020; 130:133-141. [PMID: 32219941 DOI: 10.1111/jam.14648] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 02/10/2020] [Accepted: 03/16/2020] [Indexed: 01/01/2023]
Abstract
AIMS The purpose of this experiment was to study the bacterial diversity of traditional fermented sausages from four typical regions of China (Chengdu, Shenzhen, Changsha and Harbin) and to further evaluate their microbiological safety. METHODS AND RESULTS The diversity of the microbiota of the sausages was studied using the Illumina HiSeq platform. The results showed that compared with the highest diversity of fermented bacteria in Guangdong, the bacterial diversity of fermented sausage was the lowest in Sichuan. The percentage of dominant phylum (Firmicutes, Cyanophyta, Proteobacter) were 78·39, 13·13 and 7·14% in SC, 35·47, 30·36 and 28·04% in GD, 54·81, 28·91 and 14·00% in HN, 20·20, 58·16 and 17·31% in HB respectively. The main genus distribution of fermented sausages in different regions is varied, but lactic acid bacteria and cyanobacteria are generally the main ones. Traditional fermented sausages using natural fermentation methods have poor microbiological safety, and pathogenic and spoilage micro-organisms such as Acinetobacter, Brochothrix and Pseudomonas have been detected in all four regions. CONCLUSIONS The results in this paper provide a microbiota profile of four typical fermented sausages in China. There is a big difference in the microbiota of sausages in different regions, and the good flavour of traditional Chinese fermented sausage is related closely with the abundant microbial resources, however, the natural fermentation method also expose to the product security threats, including spoilage, pathogenic micro-organisms and biogenic amines, etc. SIGNIFICANCE AND IMPACT OF THE STUDY: The results would offer guidance for industrial fermented sausage production with certain flavour and also improve the microbial resource utilization, and contribute to the control of harmful micro-organisms in traditional fermented sausage.
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Affiliation(s)
- Z Huang
- College of Food Science and Technology, Henan Agricultural University, Zhengzhou, China.,Zhengzhou City Key Laboratory for Soybean Refined Processing, Zhengzhou, China
| | - Y Shen
- College of Food Science and Technology, Henan Agricultural University, Zhengzhou, China.,Zhengzhou City Key Laboratory for Soybean Refined Processing, Zhengzhou, China
| | - X Huang
- College of Food Science and Technology, Henan Agricultural University, Zhengzhou, China.,Zhengzhou City Key Laboratory for Soybean Refined Processing, Zhengzhou, China
| | - M Qiao
- College of Food Science and Technology, Henan Agricultural University, Zhengzhou, China.,Zhengzhou City Key Laboratory for Soybean Refined Processing, Zhengzhou, China
| | - R K He
- College of Food Science and Technology, Henan Agricultural University, Zhengzhou, China.,Zhengzhou City Key Laboratory for Soybean Refined Processing, Zhengzhou, China
| | - L Song
- College of Food Science and Technology, Henan Agricultural University, Zhengzhou, China.,Zhengzhou City Key Laboratory for Soybean Refined Processing, Zhengzhou, China
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11
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Ibrahim YM, Abu El-Wafa WM. Evaluation of fosfomycin combined with vancomycin against vancomycin-resistant coagulase negative staphylococci. J Chemother 2020; 32:411-419. [DOI: 10.1080/1120009x.2020.1761638] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Yasser Musa Ibrahim
- Department of Microbiology, General Division of Basic Medical Sciences, National Organization for Drug Control and Research (NODCAR), Giza, Egypt
| | - Wael Mohamed Abu El-Wafa
- Department of Microbiology, General Division of Basic Medical Sciences, National Organization for Drug Control and Research (NODCAR), Giza, Egypt
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12
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Mu Y, Su W, Mu Y, Jiang L. Combined Application of High-Throughput Sequencing and Metabolomics Reveals Metabolically Active Microorganisms During Panxian Ham Processing. Front Microbiol 2020; 10:3012. [PMID: 31998279 PMCID: PMC6966718 DOI: 10.3389/fmicb.2019.03012] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 12/16/2019] [Indexed: 12/17/2022] Open
Abstract
Panxian ham, a traditional Chinese dry-cured ham, is protected by national geographical indication. Similar to other fermented foods, the microbial population of dry-cured ham is pivotal to taste and flavor formation. This study aimed to establish the relationship between microorganisms and metabolites during the spontaneous fermentation of Panxian ham. Multivariate analysis based on metabolomics data revealed that continuous metabolic changes occurred during the entire fermentation process, with the most significant changes occurring in the initial stage of ripening. Thirty-one significantly different metabolites (SDMs) were identified as discriminant factor, and pathway analysis suggested that these metabolites were involved in 30 pathways, including alanine, aspartate, and glutamate metabolism; glycine, serine, and threonine metabolism; and arginine and proline metabolism. Microbial community analysis using the Illumina MiSeq platform indicated that the bacterial community was more complex than the fungal community, and their succession regulation differed during processing. At the genus level, 11 bacteria and five fungi were identified as core microbes, of which Staphylococcus was the dominant bacteria and Debaryomyces and Aspergillus were the dominant fungi. Further, statistical redundancy analysis (RDA) indicated that Staphylococcus, Debaryomyces, and Chromohalobacter promoted the production of amino and fatty acids; Cobetia and Aspergillus were associated with sugar metabolism, and Kushneria, Penicillium, and Yamadazyma were closely related with organic acids. These findings provide fundamental knowledge regarding the metabolically active microorganisms in Panxian ham, helping industrial processors to develop effective strategies for standardizing quality parameters.
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Affiliation(s)
- Yu Mu
- School of Liquor and Food Engineering, Guizhou University, Guiyang, China.,Guizhou Provincial Key Laboratory of Agricultural and Animal Products Storage and Processing, Guizhou University, Guiyang, China
| | - Wei Su
- School of Liquor and Food Engineering, Guizhou University, Guiyang, China.,Guizhou Provincial Key Laboratory of Agricultural and Animal Products Storage and Processing, Guizhou University, Guiyang, China
| | - Yingchun Mu
- School of Liquor and Food Engineering, Guizhou University, Guiyang, China
| | - Li Jiang
- School of Liquor and Food Engineering, Guizhou University, Guiyang, China
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Typing of mecD Islands in Genetically Diverse Methicillin-Resistant Macrococcus caseolyticus Strains from Cattle. Appl Environ Microbiol 2019; 85:AEM.01496-19. [PMID: 31375493 DOI: 10.1128/aem.01496-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 07/29/2019] [Indexed: 11/20/2022] Open
Abstract
Macrococcus caseolyticus belongs to the normal bacterial flora of dairy cows and does not usually cause disease. However, methicillin-resistant M. caseolyticus strains were isolated from bovine mastitis milk. These bacteria had acquired a chromosomal island (McRI mecD -1 or McRI mecD -2) carrying the methicillin resistance gene mecD To gain insight into the distribution of McRI mecD types in M. caseolyticus from cattle, 33 mecD-containing strains from Switzerland were characterized using molecular techniques, including multilocus sequence typing, antibiotic resistance gene identification, and PCR-based McRI mecD typing. In addition, the same genetic features were analyzed in 27 mecD-containing M. caseolyticus strains isolated from bovine bulk milk in England/Wales using publicly available whole-genome sequences. The 60 strains belonged to 24 different sequence types (STs), with strains belonging to ST5, ST6, ST21, and ST26 observed in both Switzerland and England/Wales. McRI mecD -1 was found in different STs from Switzerland (n = 19) and England/Wales (n = 4). McRI mecD -2 was only found in 7 strains from Switzerland, all of which belonged to ST6. A novel island, McRI mecD -3, which contains a complete mecD operon (mecD-mecR1m-mecIm [where the subscript m indicates Macrococcus]) combined with the left part of McRI mecD -2 and the right part of McRI mecD -1, was found in heterogeneous STs from both collections (Switzerland, n = 7; England/Wales, n = 21). Two strains from England/Wales carried a truncated McRI mecD -3. Phylogenetic analyses revealed no clustering of strains according to geographical origin or carriage of McRI mecD -1 and McRI mecD -3. Circular excisions were also detected for McRI mecD -1 and McRI mecD -3 by PCR. The analyses indicate that these islands are mobile and may spread by horizontal gene transfer between genetically diverse M. caseolyticus strains.IMPORTANCE Since its first description in 2017, the methicillin resistance gene mecD has been detected in M. caseolyticus strains from different cattle sources and countries. Our study provides new insights into the molecular diversity of mecD-carrying M. caseolyticus strains by using two approaches to characterize mecD elements: (i) multiplex PCR for molecular typing of McRI mecD and (ii) read mapping against reference sequences to identify McRI mecD types in silico In combination with multilocus sequence typing, this approach can be used for molecular characterization and surveillance of M. caseolyticus carrying mecD.
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