scholarly journals Case Study: Misdiagnosis of Nonhemolytic Staphylococcus aureus Isolates from Cases of Bovine Mastitis as Coagulase-Negative Staphylococci

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 252
Author(s):  
Valerie E. Ryman ◽  
Felicia M. Kautz ◽  
Steve C. Nickerson
Keyword(s):  
Staphylococcus Aureus ◽  
Bovine Mastitis ◽  
Dairy Farm ◽  
Blood Agar ◽  
Coagulase Negative Staphylococci ◽  
Mannitol Salt Agar ◽  
Lactating Cows ◽  
Presumptive Identification ◽  
Microbiological Techniques

Staphylococcus aureus is one of the most concerning mastitis-causing pathogens in dairy cattle. Using basic microbiological techniques, S. aureus is typically identified by colony characteristics and hemolysis on blood agar where isolates without hemolysis are typically considered to be coagulase-negative staphylococci (CNS) isolates. Herein, we present a decade-long case study where suspected S. aureus isolates from one Georgia dairy farm were further tested to confirm presumptive identification. Presumptive identification of bacterial growth from 222 mammary secretions from bred Holstein heifers and lactating cows was conducted at the time of collection. Presumptive identification of S. aureus on blood agar was based on observation of colony morphology, color, and presence or absence of a broad zone of incomplete hemolysis and a smaller zone of complete hemolysis at 48 h. Those without hemolysis were presumptively characterized as CNS. All isolates were further plated on mannitol salt agar and a coagulase test was performed. A positive for both of these tests together was deemed to be S. aureus. A selection of isolates was tested using API® Staph to biochemically confirm S. aureus identification. Data showed that 63.96% of isolates presumed to be CNS isolates were identified as S. aureus, 9.46% of isolates presumed to be CNS isolates were identified as coagulase-positive staphylococci (CPS) species (but not S. aureus), and 26.58% of samples that were presumed to be CNS isolates were identified correctly.

Staphylococcus aureus Nasal Carriage in Medical Students of Universiti Teknologi MARA

2017 ◽  
Vol 2 (1) ◽  
pp. 29 ◽  
Author(s):  
Zaini Mohd Zain ◽  
Muhammad Fikri Johari ◽  
Nurul Shahirah Mohd Husin ◽  
Nurul Syamimi Rozman ◽  
Athirah Ab Rashid ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Medical Students ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Nasal Carriage ◽  
Tissue Necrosis ◽  
Mannitol Salt Agar ◽  
Microbiological Techniques ◽  
Polymerase Chain ◽  
Low Prevalence ◽  
Panton Valentine Leukocidin

Introduction: To determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage and detection of S. aureus leukotoxins among medical students of Universiti Teknologi MARA. Methods: Both sides of the anterior nares of 136 volunteers, comprising 68 preclinical and 68 clinical medical students, were swabbed and immediately cultured onto mannitol salt agar for growth of S. aureus. Standard microbiological techniques were conducted to identify and confirm the S. aureus colonies and susceptibility test against oxacillin were conducted by using Kirby-Bauer method to determine their resistance to methicillin. Polymerase chain reaction was performed for detection of leukotoxins, i.e., Panton-Valentine Leukocidin (PVL) and -haemolysin genes. Results: Nineteen students (14%) consisting of 10 preclinical (14.7%) and 9 clinical (13.2%) were nasal carriers of S. aureus. However, none of the S. aureus isolates were MRSA. No PVL gene was detected but eight of them were positive for -haemolysin gene. Conclusion: There were no MRSA nasal carriers among the medical students, but a low prevalence of S. aureus nasal carriers was detected. These carriers do not pose as high risk because none of the strains of S. aureus possess both the -haemolysin toxin and the PVL toxin that are associated with tissue necrosis.

scholarly journals Efficacy and Pharmacokinetics of Bacteriophage Therapy in Treatment of Subclinical Staphylococcus aureus Mastitis in Lactating Dairy Cattle

2006 ◽  
Vol 50 (9) ◽  
pp. 2912-2918 ◽  
Author(s):  
J. J. Gill ◽  
J. C. Pacan ◽  
M. E. Carson ◽  
K. E. Leslie ◽  
M. W. Griffiths ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bovine Mastitis ◽  
Treated Group ◽  
Microbial Infection ◽  
Cure Rate ◽  
Bacteriophage Therapy ◽  
Lactating Cows ◽  
Cscl Gradient ◽  
Serial Samples ◽  
Lactating Dairy Cattle

ABSTRACT Bovine mastitis is an inflammation of the udder caused by microbial infection. Mastitis caused by Staphylococcus aureus is a major concern to the dairy industry due to its resistance to antibiotic treatment and its propensity to recur chronically. Growing concerns surrounding antibiotic resistance have spurred research into alternative treatment methods. The ability of lytic S. aureus bacteriophage K to eliminate bovine S. aureus intramammary infection during lactation was evaluated in a placebo-controlled, multisite trial. Twenty-four lactating Holstein cows with preexisting subclinical S. aureus mastitis were treated. Treatment consisted of 10-ml intramammary infusions of either 1.25 × 1011 PFU of phage K or saline, administered once per day for 5 days. The cure rate was established by the assessment of four serial samples collected following treatment. The cure rate was 3 of 18 quarters (16.7%) in the phage-treated group, while none of the 20 saline-treated quarters were cured. This difference was not statistically significant. The effects of phage intramammary infusion on the bovine mammary gland were also studied. In healthy lactating cows, a single infusion of either filter-sterilized broth lysate or a CsCl gradient-purified phage preparation elicited a large increase in the milk somatic cell count. This response was not observed when phage was infused into quarters which were already infected with S. aureus. Phage-infused healthy quarters continued to shed viable bacteriophage into the milk for up to 36 h postinfusion. The phage concentration in the milk suggested that there was significant degradation or inactivation of the infused phage within the gland.

scholarly journals Staphylococcus aureus: Prevalence among normal healthy individuals

2013 ◽  
Vol 2 (2) ◽  
pp. 160-164
Author(s):  
D Finney ◽  
R Ranganathan ◽  
AKS Khan ◽  
J Shanmugam
Keyword(s):  
Staphylococcus Aureus ◽  
Nasal Swab ◽  
Throat Swab ◽  
Research Centre ◽  
Carrier Status ◽  
Healthy Individuals ◽  
Coagulase Negative Staphylococci ◽  
College Hospital ◽  
Mannitol Salt Agar ◽  
Hospital Infection Control

Background: To determine the prevalence of Staphylococcus aureus among normal healthy individuals in relation to age, gender and site of isolation. Methods: A cross sectional study was conducted among healthy students and staff volunteers between the age group 15-65 years from Gulf Medical University (GMU) and Gulf Medical College Hospital and Research Centre (GMCH&RC), Ajman. Aseptically collected nasal and throat swabs were processed for direct Gram stain Microscopy and cultured on appropriate media. Based on the growth on Mannitol Salt Agar and tube coagulase test Staphylococcus aureus and Coagulase negative Staphylococci (CoNS) were grouped. Results: Of the 127 voulnteers screened 67 were from GMU and 60 from GMCH&RC. From 49/127 (38.5%) volunteers 124 Staphylococci isolates were isolated. Of which 62 (50%) were Staphylococcus aureus and 62 (50%) were CoNS. Among the 62 Staphylococcus aureus 35 (56.45%) were from nasal swab and 27 (43.54%) were from throat swab. Of the 62 CoNS 44 (70.96%) were from nasal swab, 4 (6%) from throat swab and 14 (22.58%) were from both nasal and throat swabs. Conclusion: The study revealed the asymptomatic inhabitation of Staphyloccus aureus in the nose and throat of healthy individuals. This should be seriously looked into since this in future may lead to carrier status. This alarms the hospital infection control committee to screen students and staff on regular basis to minimize the carrier status to protect the community. Nepal Journal of Medical Sciences | Volume 02 | Number 02 | July-December 2013 | Page 160-164 DOI: http://dx.doi.org/10.3126/njms.v2i2.8968  

Isolation and Identification of Staphylococcus Aureus from Dairy Farms in Bishoftu Town, Ethiopia

2021 ◽  
Author(s):  
Sara Amanuel Bude ◽  
Abdi Kidane Mengesha
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Farms ◽  
Nutrient Agar ◽  
Blood Agar ◽  
Swab Sample ◽  
Biochemical Tests ◽  
Isolation And Identification ◽  
Mannitol Salt Agar ◽  
Milk Samples ◽  
Golden Yellow

Abstract A cross-sectional study was conducted from February, 2020 to March, 2020 in selected dairy farms in Bishoftu Town to isolate and identify Staphylococcus aureus from milk samples, swab (teat swab, tank swab and bucket swab) samples. The samples were transported to microbiology laboratory and, isolation and identification of an organism was based on morphological, cultural and biochemical characteristics. Accordingly a total of 120 samples of them 58 milk sample, 58 polled teat swab sample, 2 polled tank swab sample and 2 polled bucket swab samples. Those milk samples and swab sample were collected and cultured parallel on both Blood agar and nutrient agar. Out of total samples 68/120 were well grown on both Medias and sub cultured on nutrient agar for farther identification using Primary and secondary biochemical tests. Accordingly, 68 milk samples were shown typical large, round, golden yellow colonies with hemolysis when grown on blood agar, round shaped grape like clusters are seen under microscope after stained with grams stain, and catalase positive Staphylococcus aureus with bubble formation is observed and typical yellow pigmentation on mannitol salt agar which is selective media for genus Staphylococcus. Finally, 68(56.67%) Staphylococcus aureus were identified with coagulase test with the clumping result observed. Hence, implementing hygiene conditions, creation of awareness on control and prevention of subclinical mastitis in dairy farms and conducting drug sensitivity test for Staphylococcus aureus is recommended.

scholarly journals Bovine Mastitis in Ethiopia

2021 ◽  
Author(s):  
Tadele Tolosa Fulasa ◽  
Feyissa Begna Deressa
Keyword(s):  
Risk Factors ◽  
Staphylococcus Aureus ◽  
Production System ◽  
Agricultural Production ◽  
Smallholder Farmers ◽  
Bovine Mastitis ◽  
Clinical Mastitis ◽  
E Coli ◽  
Lactating Cows ◽  
Parity Number

Ethiopia is located in tropical region and livestock production represents a major national resource and forms an integral part of the Agricultural production system and livelihood of the society. Dairy farming being one of the agricultural production in Ethiopia, is practiced mainly as an extensive type of management system, which involves smallholder farmers in rural areas and semi-intensive and intensive managements in per urban and urban areas. Despite a large number of milking cows, there is low milk production because of many factors, including low genetic potential of indigenous breeds, extensive and poor husbandry practices, and widespread livestock diseases. Among the dairy cows’ diseases, mastitis is prevalent in the dairy production system incurring high economic losses and social burden. Several reports on mastitis in Ethiopia are present but are scattered. We focused on reviewing articles published in indexed journals reporting bovine mastitis to summarize its common etiologies, prevalence, and risk factors in Ethiopia. The common pathogens reported from different parts of Ethiopia are Staphylococcus aureus (Staph. aureus), non-aureus staphylococci, Streptococcus spp. (Strep. agalactiae, Strep. dysgalactiae, Strep. uberis), coliforms (E. coli, Klebsiella pneumonae), Trueperella pyogenes and Mannheimia haemolytica (M. haemolytica), Pseudomonas aeruginosa (P. aeroginosa), Enterobater aerogenes, Bacillus species, Micrococcus species. Staphylococcus aureus and E. coli are the most common isolates from clinical mastitis (CM). Staphylococcus aureus is also the most frequently isolated pathogen from sub-clinical mastitis (SCM). Sub-clinical mastitis which usually ranges from 25.4% to 73.3%, is highly prevalent than the clinical cases of mastitis which ranges from 3.2% to 26.5%. Several mastitis risk factors were reported. These were breed of animals, parity number, stage of lactation, presence of teat/udder lesion and hygiene measure of the farms. Thus, it is essential to plan and implement control measures including maintenance of good dairy farm environment, udder and milking hygiene at farm level; regular monitoring of udder health with special attention to exotic, crossbred and lactating cows and culling of older cows. Isolation, characterization and conducting antibacterial sensitivity test should be integral part of mastitis control strategy for effective control of the mastitis causing pathogens.

scholarly journals Mannitol Fermenting Methicillin-Resistant Coagulase Negative Staphylococci Isolated From Diabetic Foot Infections

2020 ◽  
Vol 11 (4) ◽  
pp. 6095-6101
Author(s):  
Samira Fattah Hamid ◽  
Aza Bahadeen Taha
Keyword(s):  
Staphylococcus Aureus ◽  
Diabetic Foot ◽  
Methicillin Resistance ◽  
Meca Gene ◽  
Rrna Gene ◽  
Human Pathogens ◽  
Coagulase Negative Staphylococci ◽  
Mannitol Salt Agar ◽  
Methicillin Resistant ◽  
Diabetic Foot Infections

Detection of mannitol fermenting coagulase-negative staphylococci is frequently unnoticed when Staphylococcus aureus is screening in the laboratory. On the other hand, the emergence of coagulase-negative staphylococci as critical human pathogens need dependable methods for the identification of clinically significant coagulase-negative staphylococci to understand the epidemiology of infections caused by these bacteria. The study aimed to identify mannitol fermenting coagulase-negative staphylococci that assumed to be Staphylococcus aureus as they formed yellow colonies on Mannitol Salt agar plates. Samples were taken from eighty-four patients with diabetic foot infections. The specimen was cultured on Blood agar and Mannitol Salt agar. Mannitol fermenting coagulase-negative staphylococci isolates diagnosed through Vitek2 system then confirmed by detecting 16S rRNA gene and absence of the nuc gene. Antibiotic sensitivity and methicillin resistance were detected by Vitek2 system, then methicillin resistance was confirmed by Oxacillin Salt Agar Screen test and detection of the mecA gene. Out of 81 Staphylococcus isolated from foot and nose of diabetic foot patients, twenty isolates were mannitol fermenting coagulase-negative staphylococci, they related to following species; Staphylococcus haemolyticus, staphylococcus lentus, Staphylococcus xylosus, Staphylococcus lugdunensis, Staphylococcus hominis, Staphylococcus galinarum and Staphylococcus saprophyticus). The majority of them (85%) were phenotypically methicillin-resistant and genotypically harbouring mecA gene. 80% were resistant to Erythromycin, 70% to Clindamycin, 35% to Trimethoprim-Sulphamethoxazole, 30% to Gentamicin and Rifampicin, 15% to Levofloxacin and Teicoplanin. 30% expressed inducible clindamycin resistance.

scholarly journals Bacterial factors of mastitis in lactating women and its effect on the physical properties and chemical composition of breast milk

2021 ◽  
Vol 67 (3) ◽  
pp. 172-177
Author(s):  
Xu Shuyang ◽  
Yu Qiang
Keyword(s):  
Staphylococcus Aureus ◽  
Chemical Composition ◽  
Breast Milk ◽  
Physical Properties ◽  
Inflammatory Lesion ◽  
Freezing Temperature ◽  
Coagulase Negative Staphylococci ◽  
Mannitol Salt Agar ◽  
Lactating Women ◽  
Milk Sugar

Mastitis is a complication seen in some breastfeeding mothers and is the most common inflammatory lesion of the breast in breastfeeding mothers. In this complication, breast milk undergoes chemical and physical changes. It can lead to a drop in breastfeeding, weight loss, and, consequently, stunted growth of infants. Bacteria are the main cause of breast inflammation. Therefore, in this study, bacterial factors of mastitis were evaluated in lactating women. Also, their effects were considered on the physical properties and chemical composition of mothers' breast milk. For this purpose, 210 breastfeeding mothers referred to health centers were randomly selected, and their milk samples were collected. In addition to collecting mothers' demographic information by a questionnaire, the chemical composition (sugar, protein, and fat) and the physical properties (pH, density, and freezing temperature) of milk were measured. Bacterial evaluations were performed on the milk of these mothers by catalase test, coagulase test, and mannitol salt agar. Data were analyzed by SPSS software, Chi-square, Mann-Whitney U test, and T-test. The results showed that 56 mothers had mastitis, and Staphylococcus aureus and coagulase-negative staphylococci were the main bacteria in the milk of these mastitis mothers. These bacteria caused physical and chemical changes in breast milk so that mothers with Staphylococcus aureus mastitis had less sugar in their milk, and mothers with coagulase-negative staphylococci had less protein in their milk. Therefore, Staphylococcus aureus may reduce milk sugar by consuming milk sugar, and coagulase-negative staphylococci may also target milk protein. But to confirm these results, a larger population of mothers with mastitis is needed. Further studies are also needed to prove this result.

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