scholarly journals Case report: characterization of a persistent, treatment-resistant, novel Staphylococcus aureus infection causing chronic mastitis in a Holstein dairy cow

2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Ellie J. Putz ◽  
Mitchell V. Palmer ◽  
Hao Ma ◽  
Eduardo Casas ◽  
Timothy A. Reinhardt ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Cow ◽  
Immune Escape ◽  
Collecting Duct ◽  
Clinical Signs ◽  
Treatment Resistance ◽  
Health Concern ◽  
Valuable Insight ◽  
Naturally Occurring

Abstract Background Mastitis is the most common health concern plaguing the modern dairy cow and costs dairy producers estimates of two billion dollars annually. Staphylococcus aureus infections are prevalent, displaying varied disease presentation and markedly low cure rates. Neutrophils are considered the first line of defense against mastitis causing bacteria and are frequently targeted in the development of treatment and prevention technologies. We describe a case of naturally occurring, chronic mastitis in a Holstein cow (1428), caused by a novel strain of S. aureus that was not able to be cleared by antibiotic treatment. Case presentation The infection was identified in a single quarter, 2 months into the cow’s first lactation. The infection persisted for the following 20 months, including through dry off, and a second calving and lactation. This case of mastitis was associated with a consistently high somatic cell count, however presented with no other clinical signs. This cow was unsuccessfully treated with antibiotics commonly used to treat mastitis, consisting of two rounds of treatment during lactation and an additional round at the beginning of dry off. The chronic infection was also unchanged through an experimental mid-lactation treatment with pegylated granulocyte-colony stimulating factor (PEG-gCSF) and an additional periparturient treatment with PEG-gCSF. We isolated milk neutrophils from 1428 and compared them to two cows challenged with experimental S. aureus, strain Newbould 305. Neutrophils from 1428’s milk had higher surface expression of myeloperoxidase compared to experimental Newbould challenged animals, as well as increased presence of Neutrophil Extracellular Traps. This suggests a heightened activation state of neutrophils sourced from 1428’s naturally occurring infection. Upon postmortem examination, the affected quarter revealed multifocal abscesses separated by fibrous connective tissues. Abscesses were most common in the gland cistern and collecting duct region. Microscopically, the inflammatory reaction was pyogranulomatous to granulomatous and consistent with botryomycosis. Colonies of Gram-positive cocci were found within the eosinophilic matrix of the Splendore-Hoeppli reaction within granulomas and intracellularly within the acinar epithelium. Conclusions Collectively, we describe a unique case of chronic mastitis, the characterization of which provides valuable insight into the mechanics of S. aureus treatment resistance and immune escape.

scholarly journals Genomic investigation of a dengue virus outbreak in Thiès, Senegal, in 2018

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amy Gaye ◽  
Tolla Ndiaye ◽  
Mouhamad Sy ◽  
Awa B. Deme ◽  
Alphonse B. Thiaw ◽  
...  
Keyword(s):  
West Africa ◽  
Dengue Virus ◽  
Clinical Signs ◽  
Health Concern ◽  
Public Health Concern ◽  
Local Circulation ◽  
Viral Genomes ◽  
Genomic Characterization ◽  
The City

AbstractDengue virus is a major and rapidly growing public health concern in tropic and subtropic regions across the globe. In late 2018, Senegal experienced its largest dengue virus outbreak to date, covering several regions. However, little is known about the genetic diversity of dengue virus (DENV) in Senegal. Here we report complete viral genomes from 17 previously undetected DENV cases from the city of Thiès. In total we identified 19 cases of DENV in a cohort of 198 individuals with fever collected in October and November 2018. We detected 3 co-circulating serotypes; DENV 3 was the most frequent accounting for 11/17 sequences (65%), 4 (23%) were DENV2 and 2 (12%) were DENV1. Sequences were most similar to recent sequences from West Africa, suggesting ongoing local circulation of viral populations; however, detailed inference is limited by the scarcity of available genomic data. We did not find clear associations with reported clinical signs or symptoms, highlighting the importance of testing for diagnosing febrile diseases. Overall, these findings expand the known range of DENV in Senegal, and underscore the need for better genomic characterization of DENV in West Africa.

scholarly journals Characterization of Staphylococcus aureus ST3320 clone causing fatal respiratory infection in rabbits

2021 ◽  
Vol 29 (2) ◽  
pp. 99
Author(s):  
Jinxiang Wang ◽  
S. Sun ◽  
Y. Chen ◽  
D. Chen ◽  
L. Sang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Respiratory Infection ◽  
Antimicrobial Susceptibility ◽  
Virulence Genes ◽  
Clonal Complex ◽  
Clinical Signs ◽  
Sequence Type ◽  
Intranasal Infection ◽  
Pathological Lesions

<em>Staphylococcus aureus</em> is a well-known pathogen that infects humans and animals. However, information on the fatal respiratory infection in rabbits caused by<em> S. aureus</em> is still limited. In the present study, a <em>S. aureus</em> isolate designated ND01 was recovered from lung samples of rabbits that died of fatal respiratory infection, and the ND01 was characterised by intranasal infection of rabbits, multi-locus sequencing typing, screening virulence genes and testing antimicrobial susceptibility. Clinical signs of matted forepaws and pathological lesions of haemorrhagic tracheitis and necrotising haemorrhagic pneumonia were observed in the ND01 infected rabbits, which were identical to those of naturally infected ones. The sequence type of the ND01 was defined as ST3320 and the ND01 was further grouped into the clonal complex 398. Notably, the ND01 was <em>pvl-positive</em> <em>S. aureus</em> and carried the human-associated scn gene. Moreover, the ND01 was methicillin-susceptible <em>S. aureus</em> and was susceptible to 6 of 10 tested antibiotics. This study described the characteristics of the ND01 causing fatal respiratory infection in rabbits. The results are helpful to further the understanding of the pathogenicity of S. aureus ST3320 clone in rabbits. The results also highlighted that operators must be on the alert for the colonisation of <em>pvl-positive</em> <em>S. aureus</em> in rabbits and potential transmission events between rabbits and humans.

Central nervous system lesions caused by canine distemper virus in 4 vaccinated dogs

2021 ◽  
pp. 104063872110092
Author(s):  
Gimena Feijóo ◽  
Kanji Yamasaki ◽  
Luis Delucchi ◽  
José Manuel Verdes
Keyword(s):  
Choroid Plexus ◽  
Canine Distemper Virus ◽  
Clinical Signs ◽  
Ependymal Cells ◽  
South American ◽  
Canine Distemper ◽  
Pia Mater ◽  
Naturally Occurring ◽  
Type Strains

We examined the cerebellum and cerebrum of 4 vaccinated dogs, 3–60-mo-old, that displayed clinical signs of canine distemper virus (CDV) infection, and died 7–40 d after developing neurologic signs. The main histologic lesions were demyelination, gliosis, meningitis, perivascular lymphocytic cuffing, and inclusion bodies. These lesions were similar in all 4 cases regardless of the time since vaccination, except that meningoencephalitis and gliosis were subacute in 3 dogs and chronic in 1 dog. However, these differences did not appear to be related to their vaccination status. Immunohistologically, a CDV-positive immunoreaction was seen mainly in astrocytes, neurons and their axons, lymphocytes around and in the blood vessels of the pia mater and choroid plexus, ependymal cells of each ventricle, and the cells of the choroid plexus. The histologic and immunohistologic changes were similar in the cerebellum and cerebrum. The genetic characterization of the virus strains in 2 of these naturally occurring canine distemper cases confirmed that they were South American wild-type strains (Kiki and Uy251) belonging to the EU1/SA1 lineage. These strains are not included in the commercial CDV vaccines available in Uruguay.

scholarly journals The lone S41 family C-terminal processing protease in Staphylococcus aureus is localized to the cell wall and contributes to virulence

Microbiology ◽  
2014 ◽  
Vol 160 (8) ◽  
pp. 1737-1748 ◽  
Author(s):  
Ronan K. Carroll ◽  
Frances E. Rivera ◽  
Courtney K. Cavaco ◽  
Grant M. Johnson ◽  
David Martin ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Critical Role ◽  
Multidrug Resistant ◽  
Health Concern ◽  
Host Immune System ◽  
Increased Sensitivity ◽  
Processing Protease

Staphylococcus aureus is a versatile pathogen of humans and a continued public health concern due to the rise and spread of multidrug-resistant strains. As part of an ongoing investigation into the pathogenic mechanisms of this organism we previously demonstrated that an intracellular N-terminal processing protease is required for S. aureus virulence. Following on from this, here we examine the role of CtpA, the lone C-terminal processing protease of S. aureus. CtpA, a member of the S41 family, is a serine protease whose homologues in Gram-negative bacteria have been implicated in a range of biological functions, including pathogenesis. We demonstrate that S. aureus CtpA is localized to the bacterial cell wall and expression of the ctpA gene is maximal upon exposure to conditions encountered during infection. Disruption of the ctpA gene leads to decreased heat tolerance and increased sensitivity when exposed to components of the host immune system. Finally we demonstrate that the ctpA − mutant strain is attenuated for virulence in a murine model of infection. Our results represent the first characterization of a C-terminal processing protease in a pathogenic Gram-positive bacterium and show that it plays a critical role during infection.

scholarly journals Genomic investigation of a dengue virus outbreak in Thiès, Senegal, in 2018

2020 ◽  
Author(s):  
Amy Gaye ◽  
Tolla Ndiaye ◽  
Mouhamad Sy ◽  
Awa B. Deme ◽  
Alphonse B. Thiaw ◽  
...  
Keyword(s):  
West Africa ◽  
Dengue Virus ◽  
Clinical Signs ◽  
Health Concern ◽  
Metagenomic Sequencing ◽  
Local Circulation ◽  
Genomic Characterization ◽  
Virus Genomes ◽  
The City

AbstractDengue virus is a major and rapidly growing public health concern in tropic and subtropic regions across the globe. In late 2018, Senegal experienced its largest dengue virus outbreak to date, covering several regions. However, little is known about the genetic diversity of dengue virus (DENV) in Senegal. Here we used molecular tools including metagenomic sequencing to identify 19 previously undetected dengue virus cases from the city of Thiès and assemble 17 complete virus genomes. DENV3 was the most frequent serotype; 11 sequences (65%) were DENV3, 4 sequences were DENV2 and 2 were DENV1. Sequences were closest to recent sequences from West Africa, suggesting ongoing local circulation of viral populations; however, detailed inference is limited by the scarcity of available genomic data. We did not find clear associations with reported clinical signs or symptoms, highlighting the importance of testing for diagnosing febrile diseases. Overall, these findings expand the known range of DENV in Senegal, and underscore the need for better genomic characterization of DENV in West Africa.

Molecular characterization of Staphylococcus aureus in Lebanon

2010 ◽  
Vol 138 (5) ◽  
pp. 707-712 ◽  
Author(s):  
S. T. TOKAJIAN ◽  
P. ABOU KHALIL ◽  
D. JABBOUR ◽  
M. RIZK ◽  
M. J. FARAH ◽  
...  
Keyword(s):  
Public Health ◽  
Staphylococcus Aureus ◽  
Molecular Characterization ◽  
Protein A ◽  
Multi Locus Sequence Typing ◽  
Health Concern ◽  
Human Pathogen ◽  
Public Health Concern ◽  
Sequence Types

SUMMARYStaphylococcus aureus is an important human pathogen and is a growing public health concern. In this study, 130 S. aureus, 93 methicillin-resistant S. aureus (MRSA) and 37 methicillin-sensitive S. aureus (MSSA), clinical isolates recovered from Lebanon were typed by protein A gene (spa) sequencing and multi-locus sequence typing (MLST). Forty-eight different spa types were identified and clustered into 30 different groups. MLST revealed 10 sequence types (STs) among the isolates. There were eight major MRSA clones defined as isolates with the same ST and the same SCCmec type. The majority of the PVL-positive isolates (53%) were ST80-MRSA-IVc. Systematic surveillance of both hospital and community isolates in Lebanon together with measures designed to limit the spread are required.

scholarly journals Clinical and molecular characterization of both methicillin-resistant andsensitive staphylococcus aureus mastitis

2019 ◽  
Vol 70 (3) ◽  
pp. 1743
Author(s):  
A. OREIB ◽  
H. KHALIFA ◽  
A. EID ◽  
A. AHMED ◽  
T. SHIMAMOTO ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Bovine Mastitis ◽  
Clinical Signs ◽  
Subclinical Mastitis ◽  
Therapeutic Success ◽  
Methicillin Resistant ◽  
Marked Resistance

This study targeted bovine mastitis as a possible source of livestock-associated methicillin-resistant Staphylococcus aureus (MRSA), to identify clinical signs associated with MRSA- and non-MRSA-associated mastitis. Thirty-eight mastitis cases (68 infected quarters) were investigated. Gram-positive cocci-shaped isolates were selected based on Baird Parker agar growth as well as Gram-stained bacterial smears. Molecular screening for Staphylococcus aureus (S. aureus) yielded 17 isolates, of which five (29.41%) were methicillin resistant. The five isolates were mecA positive, but mecC negative. Multilocus sequence typing (MLST) indicated that sequence type 1 (ST1) was the identified type of all isolates of MRSA. S. aureus-associated cases showed different clinical forms of mastitis, including subclinical, acute, chronic, and gangrenous. Additionally, subclinical mastitis was the only detected condition associated with MRSA, which may represent a potential hidden risk for humans. Phenotypically, isolates of MRSA showed resistance to all of the tested β-lactam antimicrobials, with marked resistance to tetracycline and gentamycin. Based on our knowledge, this is the first report to identify MRSA ST1 in Egypt. Bovine mastitis could be a source for the dissemination of MRSA to humans and other animals. Additionally, while methicillin-resistance may have no effect on the clinical outcome of mastitis, it does affect therapeutic success, particularly when β-lactam antimicrobials are used.

Characterization of methicillin-resistant Staphylococcus aureus from residents and the environment in a long-term care facility

2015 ◽  
Vol 143 (14) ◽  
pp. 2985-2988 ◽  
Author(s):  
C. LUDDEN ◽  
G. BRENNAN ◽  
D. MORRIS ◽  
B. AUSTIN ◽  
B. O'CONNELL ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Long Term Care ◽  
Care Facility ◽  
Health Concern ◽  
Term Care ◽  
Methicillin Resistant ◽  
Term Care Facility ◽  
Long Term Care Facility

SUMMARYMethicillin-resistant Staphylococcus aureus (MRSA) is a major public health concern associated with residence in a long-term care facility (LTCF). The aim of this prospective study was to characterize MRSA isolated from residents over a 1-year period and their physical environment over a 2-year period. MRSA was recovered from 17/64 residents (R) of a LTCF and from 42 environmental (E) sites. All isolates carried the mecA gene and lacked the mecC and Panton–Valentine leukocidin (PVL) genes. Thirteen spa types were identified with t032 being the most frequent (41% of total; n = 8R, 16E), followed by t727 (22% of total; n = 13E), and t8783 (10% of total; n = 6E). Five spa types were each represented by single isolates. Thirty-nine isolates were of spa types associated with the multilocus sequence type ST22 (t032, 41%; spa-CC22, 68%) and reflect the predominance of ST22 in Irish hospitals. The uncommon spa types t727, t8783, t1372, t3130, t10038 were present in the environment but not detected in residents and are infrequently observed in Ireland.

scholarly journals Isolation and characterization of a catalase-negative strain of Staphylococcus aureus

1976 ◽  
Vol 3 (1) ◽  
pp. 77-78
Author(s):  
K K Tu ◽  
W A Palutke
Keyword(s):  
Staphylococcus Aureus ◽  
Cellular Morphology ◽  
Biochemical Reactions ◽  
Isolation And Characterization ◽  
Naturally Occurring

An unusual, naturally occurring strain of Staphylococcus aureus is characterized. It is typical in colony and cellular morphology, coagulase production, and other biochemical reactions as compared to S. aureus (ATCC-25923), except that it is catalase negative and fails to ferment mannitol anaerobically.

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