Rapid Antimicrobial Susceptibility Testing to Combat Resistance
Introduction Antimicrobial Susceptibility Testing (AST) plays a crucial role in combating bacterial infections and addressing the growing global challenge of antibiotic resistance. Antibiotics, ranging from β-lactams to macrolides, have saved millions of lives since the accidental discovery of penicillin by Alexander Fleming in 1928. Despite their effectiveness, widespread misuse in healthcare and agriculture has accelerated the emergence of resistant pathogens, causing an estimated 700,000 deaths annually, a figure projected to rise to 10 million by 2050 (Brogan & Mossialos, 2016). (https://share.google/images/TSneDwQ3EQjAbSPAX) Importance of AST in Clinical Practice AST allows clinicians to determine which antibiotics are effective against specific bacterial isolates, enabling targeted therapy and reducing reliance on broad-spectrum antibiotics. Timely and accurate AST is critical, as delayed treatment can increase patient mortality and worsen clinical outcomes. Traditional AST Methods Disk Diffusion (Kirby–Bauer Test): Convenient and cost-effective, providing qualitative results based on the zone of inhibition around antibiotic discs. Broth Microdilution: Offers precise Minimum Inhibitory Concentration (MIC) values, essential for correct dosage selection. Miniaturized 96-well plates allow testing of multiple antibiotics simultaneously. Etest: Gradient diffusion method that combines ease of use with quantitative MIC determination, correlating well with broth microdilution results. Automated AST Systems Modern laboratories increasingly rely on automated systems like VITEK®, BD Phoenix™, Sensititre™, and MicroScan WalkAway®. These platforms streamline bacterial identification and susceptibility testing, reduce manual workload, and provide faster results for effective patient care. Emerging Technologies Rapid AST innovations using optical imaging, micro-channel resonators, and biosensors are being developed. Some technologies can deliver results within hours and may allow direct testing on patient samples without pre-culturing, which is essential for timely therapy, especially in critical care. Conclusion AST remains an essential practice of modern clinical microbiology. By providing rapid and accurate results, AST enables targeted antibiotic therapy, reduces the use of broad-spectrum drugs, and improves patient outcomes. Continued innovation and integration of rapid AST technologies into routine practice are vital to combating antibiotic-resistant infections worldwide. The miniAST Veterinary Antibiotic Susceptibility Test Analyzer, a tool designed to help combat antimicrobial resistance with game-changing features: Feature Benefit Fast Results Get results in just 6 hours, enabling swift and confident treatment. Automated Interpretations Instantly deliver precise susceptibility profiles, supporting faster, more informed clinical decisions and optimizing patient care. Dual-Sample Testing Double the efficiency with simultaneous analysis of two samples at once. High Accuracy Achieve an impressive 92% accuracy rate compared to traditional disc diffusion tests. 📌 Note for Veterinarians: The miniAST Veterinary Antibiotic Susceptibility Test Analyzer is available exclusively to licensed veterinarians and veterinary hospitals. 📩 How to Order miniAST To purchase miniAST or request a quotation, please contact our sales team or email our customer service: 📧 service@bioguardlabs.com ☎️ Please include your hospital name and contact number so our sales representative can follow up with you directly. Source: World Health Organization (WHO) – Antimicrobial Resistance 🔗 https://www.who.int/news-room/fact-sheets/detail/antimicrobial-resistance Clinical and Laboratory Standards Institute (CLSI) 🔗 https://clsi.org/standards/products/microbiology/ European Committee on Antimicrobial Susceptibility Testing (EUCAST) MIC cut-offs and AST interpretation standards. 🔗 https://www.eucast.org/clinical_breakpoints/ Bauer AW, Kirby WMM, Sherris JC, Turk M. (1966) Antibiotic susceptibility testing by a standardized single disk method. Jorgensen JH, Ferraro MJ. (2009) Antimicrobial susceptibility testing: a review of general principles and contemporary practices. Clin Infect Dis. 49:1749–1755. Puskarich MA et al. (2011) Association between timing of antibiotic administration and mortality from septic shock.
Canine Parvovirus
Canine Parvovirus CHINESE EDITION IS WRITTEN BY DR. WANG, SHIH-HAO / ENGLISH EDITION IS TRANSLATED AND EDITED BY DR. LIN, WEN-YANG (WESLEY) Abstract The canine parvovirus (CPV) is a common, acute, high morbidity and high morality virus that mainly infect canine population. This virus possess highly survival rate for 5 weeks in the natural environment. It is highly contagious and easily transmitting among canine population by the fecal-oral route through contacting contaminated feces. CPV usually attack digestive system. Sometimes it may induce myocarditis among canine and cause sudden death. All ages, sexes and breeds of dogs could be susceptible to CPV, especially puppies. Clinical sighs of infected dogs may include fever, lethargy, continuous vomiting, continuous diarrhea, stinky viscous diarrhea with blood, dehydration and abdominal pain etc. Canine show signs of the disease would usually die within 3 to 5 days. There are no specific drugs for curing CPV until now. Supportive care such as consuming water-electrolyte fluid is the only present solution to maintain physiological function and relieve symptoms. The infected canine should have medical care as soon as possible; otherwise, more severe conditions like acute dehydration, hypovolemic shock, bacterial infections and death will occur. Infection prevention measures include environmental disinfection and routine vaccines. Pathogens The canine parvovirus (CPV) is an ssDNA virus, which belongs to the species carnivore protoparvovirus 1 within the genus protoparvovirus in the family parvovirus (parvoviridae). CPV is 98% identical to feline panleukopenia virus (FPLV) with variant in six coding nucleotide of structural proteins VP2: 3025, 3065, 3094, 3753, 4477, 4498 that makes CPV-2 infect canine host instead of replicating in cats. Two types of canine parvovirus were discovered – canine minute virus (CPV1) and CPV2, both can attack canine population and canidae family such as raccoons, wolves and foxes. Canine parvovirus may be susceptible to cats without pathogenic, and it is an inapparent infection. CPV2 could stably survive in feces for 5 months with ideal condition. Furthermore, CPV-2a, CPV-2b and CPV-2c type viruses have been isolated and sequenced from animals. Other than targeting on canine, large cats are susceptible to CPV-2a, CPV-2b. CPV-2c type viruses have high prevalence on infecting leopard cats. Figure 1. Model of CPV evolution showing VP2 amino acid differences between each virus and indicating the virus host ranges. (Karla M. Stucker, Virus Evolution In A Novel Host: Studies Of Host Adaptation By Canine Parvovirus, Published in 2010) Epidemiology In 1978, a novel infectious canine disease was firstly occurring in the east coast of America. Within 12 months, scientists identified CPV-2 as the aetiological key of severe symptoms among canine. Due to characters of highly contagious and potential environmental resistance, CPV-2 spread swiftly over entire USA, European countries, Australia and Asia. In 1978, canine parvovirus also invade among canine in Taiwan. Therefore, CPV caused large scale of canine death at the early stage of pandemic. By the establishment and development of CPV vaccine, global wide spreading of CPV has been rarely happen today. However, canine parvovirus still widely exists in domestic dogs and wild canidae. It became one of the canine endemic disease. Pathogenesis Incubation period of CPV-2 lasts 4 to 5 days. The virus mostly attacks rapidly dividing cells especially lymphopoietic tissues, the bone marrow, crypt epithelia of the jejunum, ileum and (in young dogs under 4 weeks old) myocardial cells. Rottweilers, black Labrador Retrievers, Doberman Pinschers, and American Pit Bull Terriers are more susceptible than other species; once they are infected, would suffer severer conditions. Besides, CPV-2 take the major place to affect canine and wild canids. After entering into hosts’ body, CPV-2 firstly replicates in oropharynx lymphoid tissues, mesenteric lymph nodes and thymus gland, then spreading to other lymph nodes, lung, liver, kidney and rapidly dividing tissues (e.g. bone marrow, intestinal epithelial cell and myocardial cell) by the blood stream. 4 to 5 days after, clinical sighs like diarrhea, vomiting, lymphopenia, anorexia, depression, dehydration, hypothermia, thrombocytopenia and neutropenia would appear. Severe dehydration and hypovolemic shock may happen due to lose large amount of fluid and protein by vomiting and diarrhea. Transmission Fecal-oral route is the main transmission pathway of CPV-2. Large amount of virus would be detected in feces of infected canine within 1 to 2 weeks of acute phase. An infected pregnant canine could transmit virus to fetus through placenta. Fomites include contaminated shoes, cages, food bowls and other utensils could serve as CPV transmitting objects also. Clinical forms There are four clinical forms according to distinct signs and lesions: enteric, myocardial, systemic infection and inapparent Infection. A. Enteric form : It is known that CPV-2 caused enteritis symptoms. This form infect host with low virus titers (around 100 TCID50). Symptoms in initial stage are sopor, loss of appetite, acute diarrhea, vomiting, dehydration, slight elevated body temperature, frailty and acting like in extreme pain. Severity of illness vary according to the age of canine, healthy condition, infectious dose of the virus, and other pathogens in intestine and so on. Typical signs of CPV induced enteritis and its course include loss of appetite, sopor, fever (39.5℃-41.5℃) within 48 hours follow vomiting. 6 to 24 hour after vomiting follow watery stool in yellow or white color, mucus stool or bloody stool with stench in severe cases. Due to consistent diarrhea and vomiting, dogs suffer worsen dehydrated condition. Common clinical pathologic examination consist assessing dehydrated condition and significant decreasing of white blood cell of dogs (400 to 3000 /μL). B. Myocardial form: This form only appear in puppies around 3 to 12 weeks of age. Major cases show pups’ age under 8 weeks. Mortality rate is extremely high with myocardial form (almost up to 100%). Clinical signs include irregular breathing, cardiac arrhythmia. Collapse, hard breathing may happen to acute cases follow death within 30 minutes. Most cases would die within 2 days. The subacute form would also die from hypoplastic heart syndrome within 60 days. Nevertheless female adult canine acquire antibodies against myocardial form by vaccination or infection, puppies may
Peritonitis in Canine
[vc_row][vc_column][vc_column_text] Peritonitis in Canine Andy Pachikerl, Ph.D Introduction: Peritonitis is the inflammation of the peritoneum, which is a silk-like membrane that lines the inner abdominal wall of mammalian bodies and covers the organs within the abdomen, and it is usually due to a bacterial or fungal infection. Peritonitis typically results in rupture (perforation) in the abdomen or causes other medical conditions. In canine or dogs this condition is not that different compared to other mammals, which is the peritoneum of the abdominal cavity, becomes inflamed. In canines, this normally occurs because of an injury by physical trauma, disease, a stomach ulcer, or other problems (Latimer, et al., 2019). The most common cause of peritonitis in canine is actually bacterial infection that moves to the abdomen from an external wound or from perforation of an internal organ. An affected dog may seem to be well, then suddenly become ill. The condition is usually painful, and most dogs will show signs of discomfort when they are been touched on the abdomen (Kine, et al., 2019). Classification and Etiology Peritonitis in dogs are classified in various ways, but there are two main methods of identification are (1) localized or diffuse and (2) primary, secondary, or tertiary. Localized septic peritonitis occurs when a small amount of contamination, whether bacterial or fungal is confined. The contamination usually originates from an intraabdominal organ due to secondary surgery or an underlying disease process, such as gastrointestinal (GI) perforation due to a foreign body. Diffuse peritonitis arises from either a larger amount of contamination or a failure to control localized septic peritonitis. Primary septic peritonitis is spontaneous, and it is the infection of the peritoneal cavity with no specific intraperitoneal source of infection detected during surgery or necropsy. This type of peritonitis is more common in cats rather than dogs, with 14% of cats with septic peritonitis having primary septic peritonitis in one study (Costello, et al., 2004; Odonez & Puyana, 2006; Culp, et al., 2009). Primary septic peritonitis is usually monomicrobial, whereas secondary septic peritonitis is often polymicrobial (Mueller, et al., 2001). In one study (Mueller, et al., 2001), bacteria cultured from patients with primary peritonitis were gram positive in 80% of dogs and in 60% of cats. It is postulated that primary septic peritonitis may result from hematogenous or lymphogenous bacterial spread, transmural bacterial migration from the GI tract, or bacterial spread from the oviducts (Culp, et al., 2009; Enberg, et al., 2006). Secondary septic peritonitis is a consequence of an underlying primary disease process and is the most common cause of septic peritonitis in dogs and cats (Mueller, et al., 2001). There are many possible causes of secondary septic peritonitis in animals; the most common are loss of integrity of the GI tract (53% to 75% of cases), foreign-body penetration, perforating ulcers (Figure 1) and surgical wound dehiscence (Mueller, et al., 2001; Costello, et al., 2004). It is the upmost recommendation that canines showing peritonitis signs should seek medical help from a veterinarian for a proper diagnosis and treatment, as it can be a life-threatening condition. Figure 1: Septic peritonitis secondary to jejunal rupture from a perforating ulcer (arrow). Symptoms of Peritonitis in Dogs In most cases, the symptoms of peritonitis in canines are easy to recognize. A dog may seem fine, then suddenly become very ill the following day. They will almost certainly show signs of pain when their abdomen is been touched (DeClue, et al., 2011). Canine that has been injured or wounded seemed fine but suddenly develop the following symptoms the next day then one may consider seeking a veterinarian right away. Fever: – normal body temperature in canine ranges from 99.5 – 102.5 ° F, whereas a body temperature of at least 103.5 ° F (39.7 ° C) can be considered as fever. Vomiting Diarrhoea Black stools Anorexia Lethargy Weakness Abdominal pain Taking unusual positions to relieve pain Low blood pressure Increased heart rate Increased respiration rate Low body temperature Pale gums Jaundice: – Jaundice in canines refers to a build-up of yellow pigment in the blood and tissue, which causes a yellow discoloration in the skin, gums, and eyes. Swelling in the abdomen Ascites: – Ascites in canines is an abnormal build-up of fluid in the abdomen. It is also called abdominal effusion. Arrhythmia: – Arrhythmia in canines is an abnormality in the rhythm of the heart, which can include the speed, strength, or regularity of heart beats. There are cases when peritonitis could become severely complicated by gut microbiota of the dog. These can lead to changes in the dog’s micro flora forever. Such a case is shown as follow. Case Presentation: An 11‐year‐old intact male Poodle was brought to Oklahoma State University, Center for Veterinary Health Sciences (OSU‐CVHS), with a record of vomiting, abdominal distention, increased serum activities of alkaline phosphatase, γ‐glutamyl transferase, and hyperbilirubinemia. The dog had received amoxicillin and clindamycin (dosage and administration route unknown) prescribed by a referred veterinarian. An abdominal ultrasonographic examination revealed a moderate amount of peritoneal fluid, widespread vascular mineralization, and a markedly thickened and irregular gallbladder wall. The abdominal fluid had a total nucleated cell count (TNCC) of 51,000/μL (CELL‐DYN 3500 analyzer; Abbott Diagnostics, Abbott Park, IL, USA), and a total protein of 5.6 g/dL via refractometry. Cytologic examination of direct smears of the abdominal fluid stained with an aqueous Romanowsky stain (Hematek 2000; Siemens Healthcare Diagnostics, Deerfield, IL, USA) demonstrated marked pyogranulomatous inflammation with abundant golden‐to‐dark green pigment, consistent with bile, present extracellularly and within macrophages. Cytologic diagnosis was bile peritonitis. No infectious organisms were identified, and successive aerobic and anaerobic bacterial cultures were negative. The dog was intravenously dosed with ampicillin/sulbactam and enrofloxacin. Exploratory abdominal laparotomy revealed a ruptured gall bladder and a cholecystectomy and duodenotomy were performed. Following surgery, the effusion persisted, despite antimicrobial therapy, and the dog’s condition began to deteriorate. Abdominal fluid collected 6 days postsurgery had a TNCC of 96,600/μL, and a total protein of 5.3 g/dL. Cytologic examination was shown to have pyogranulomatous inflammation with several yeast organisms