Newly isolated lytic bacteriophages for Staphylococcus intermedius, structurally and functionally stabilized in a hydroxyethylcellulose gel containing choline geranate: Potential for transdermal permeation in veterinary phage therapy.

In the present research work, we propose a new antimicrobial treatment for pyoderma via cutaneous permeation of bacteriophage particles conveyed in a hydroxyethylcellulose (HEC) gel integrating ionic liquid as a permeation enhancer. Ionic liquids are highly viscous fluids constituted exclusively by ions, that are usually hydrolytically stable and promote solubilization of amphipathic molecules such as proteins, hence serving as green solvents and promoting the transdermal permeation of biomolecules. In the research effort entertained herein, the synthesis and use of choline geranate for integrating a HEC gel aiming at the structural and functional stabilization of a cocktail of isolated lytic bacteriophage particles was sought, aiming at transdermal permeation in the antimicrobial treatment of animal pyoderma. The results obtained showed a high ability of the ionic liquid in enhancing transdermal permeation of the bacteriophage particles, with concomitant high potential of the HEC gel formulation in the antimicrobial treatment of animal skin infections.

Staphylococcus ursi sp. nov., a new member of the 'Staphylococcus intermedius group' isolated from healthy black bears.

Six Staphylococcus strains were isolated from healthy black bears (Ursus americanus) in the Great Smoky Mountains National Park, Tennessee, USA. Phylogenetic analysis based on complete genome, 16S rRNA, dnaJ, hsp60, rpoB and sodA genes, and MALDI-TOF-MS main spectral profiles revealed that the strains belonged to one species and showed the closest relatedness to members of the 'Staphylococcus intermedius group' (SIG), which include Staphylococcus intermedius, Staphylococcus pseudintermedius, Staphylococcus delphini and Staphyloccoccus cornubiensis. The strains were positive in SIG-specific and negative in individual species-specific PCR assays for the nuc gene. The strains can be differentiated from the other SIG species by the absence of sucrose fermentation, from S. intermedius DSM 20373T, S. pseudintermedius CCUG 49543T and S. cornubiensis DSM 105366T by the absence of methyl ß-d-glucopyranoside fermentation and from S. delphini DSM 20771T by fermentation of trehalose. DNA relatedness of the type strain MI 10-1553T with the type strains of S. delphini, S. pseudintermedius, S. intermedius and S. cornubiensis was ≤48.2 % by digital DNA-DNA hybridization and ≤92.3 % by average nucleotide identity calculations. Iso-C15:0, anteiso-C15 : 0 and anteiso-C17 : 0 were the most common fatty acids. Polar lipids consisted of phosphadidylglycerols, phospholipids, glycolipid, diphosphatidylglycerol and aminophospholipid. Cell-wall peptidoglycan was of type A3α l-Lys-Gly3 (Ser; similar to A11.2 and A11.3). The respiratory quinone belonged to menaquinone 7 (MK-7). The G+C content of MI 10-1553T was 39.3 mol%. The isolated strains represent a novel species of the genus Staphylococcus, for which we propose the name Staphylococcus ursi sp. nov. The type strain is MI 10-1553T (=ATCC TSD-55T=CCOS 1900T).

[Investigation of Skin Adherent Bacterial Flora in Dogs by MALDI-TOF MS and 16S rRNA Gene Analysis].

Due to the increase in the number of companion animal breeders in Japan, there are more opportunities for companion animals to come into contact with humans than before. Therefore, we investigated the bacterial flora adhering to the skin of dogs and the bacterial flora was analyzed for the presence of zoonotic bacteria that infect humans from companion animals. With the cooperation of students enrolled in the Department of Medical Technology and Science, Faculty of Fukuoka Health Care, International University of Health and Welfare. 39 samples were collected from the abdomen, back and paws of 13 healthy dogs using sterile swabs by the scraping method. The isolation culture was carried out only for facultative anaerobic bacteria to obligate aerobic bacteria and Bacterial identification was determined by MALDI-TOF MS and 16S rRNA gene analysis. Among the identified strains were Pasteurella canis, Staphylococcus pseudintermedius, Staphylococcus intermedius, which were difficult to detect in humans. The overall ratio of detected bacteria was 35% for coagulasenegative staphylococci, 14% for coagulase-positive staphylococci, 5% for Enterobacteriaceae, and 45% for natural environment. In the future, it is expected that extended-spectrum ß-lactamase producing bacteria and drug-resistant bacteria such as Carbapenem-resistant enterobacterales will also be transmitted to humans through contact with companion animals.

Subclinical mastitis in Lacaune sheep: Causative agents, impacts on milk production, milk quality , oxidative profiles and treatment efficacy of ceftiofur.

Mastitis is a major disease affecting dairy sheep. It is caused by microorganisms that generate inflammation of the mammary gland in response to tissue invasion. This syndrome affects the welfare of ewes, as well as the production and quality of the milk, thereby reducing its productive efficiency. Because mastitis causes inflammation process, it also increases the production of free radicals that cause lesions via lipoperoxidation, causing damage to proteins, cells and tissues. One way to minimize the impact of the disease is antimicrobial treatment. Nevertheless, the continuous use of antimicrobials contributes to microbial resistance, in addition to producing residues in the milk and derivatives if not given during the grace period. Therefore, the objective of this study was to evaluate the consequences of subclinical mastitis on ewe health, milk production, milk composition and quality. We also evaluated the susceptibility of the bacteria in vitro using disk diffusion antibiograms. Finally, we performed two-way testing of efficacy of treatment in Lacaune ewes using the same agents. In the first stage of the study, 30 lactating ewes (±90 days) were used, 10 of which were negative on the CMT (California Mastitis Test) used as control group (CG) and 20 sheep with subclinical mastitis diagnosed by CMT (MG). Samples were collected and several analyses were performed on the milk and blood. We found that ewes in the MG had higher lipid peroxidation in serum and milk, as well as lower production, with reduction of the total dry extract in milk. There were 15 isolates of Staphylococcus hyicus, four isolates of each S. epidermidis and S. intermedius, and two isolates of Corynebacterium spp. The primary hematological result was leukocytosis in ewes with mastitis. Based on the antibiogram, we chose ceftiofur for in vivo tests. In this stage, we divided the sheep with subclinical mastitis into two subgroups of 10 ewes each, to receive drug by two routes: intramuscular (IM) and intramammary (IMM). In the IMM group, of the 10 CMT-positive ewes at the beginning of the experiment, seven were already negative by the racket test 120 h after the last application (70% efficacy). In the IM group, of the 10 positive ewes, only four were negative after 120 h of the final application, a low efficacy treatment (40%). We evaluated antimicrobial residues in the milk of treated animals. We found this material within 5 days after treatment in the two forms used; despite the fact that the product's stated withholding period is 3 days. We conclude that ewes with mastitis produce less milk of lower quality. We also conclude that, although ceftiofur is 100% effective in vitro, when used in ewes with mastitis, the efficacy did not exceed 70%, and was more efficient when administered via the intramammary route.

Performance of Five Commercial Identification Platforms for Identification of Staphylococcus delphini.

The Staphylococcus intermedius group (SIG) is a collection of coagulase-positive staphylococci consisting of four distinct species, namely, Staphylococcus cornubiensis, Staphylococcus delphini, Staphylococcus intermedius, and Staphylococcus pseudintermedius SIG members are animal pathogens and rare causes of human infection. Accurate identification of S. pseudintermedius has important implications for interpretation of antimicrobial susceptibility testing data and may be important for other members of the group. Therefore, we sought to evaluate the performance of five commercially available identification platforms with 21 S. delphini isolates obtained from a variety of animal and geographic sources. Here, we show that automated biochemical platforms were unable to identify S. delphini to the species level, a function of its omission from their databases, but could identify isolates to the SIG level with various degrees of success. However, all automated systems misidentified at least one isolate as Staphylococcus aureus One matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) system was able to identify S. delphini to the species level, suggesting that MALDI-TOF MS is the best option for distinguishing members of the SIG. With the exception of S. pseudintermedius, it is unclear if other SIG members should be routinely identified to the species level; however, as our understanding of their role in animal and human diseases increases, it may be necessary and important to do so.

Reduced rates of antimicrobial resistance in Staphylococcus intermedius group and Escherichia coli isolated from diseased companion animals in an animal hospital after restriction of antimicrobial use.

The 2016 National Action Plan aims for reduction in antimicrobial resistance (AMR) to tetracyclines, third-generation cephalosporins, and fluoroquinolones in Escherichia coli isolates from livestock: to lower the tetracycline resistance of E. coli to 33% or less; to maintain the third-generation cephalosporin resistance of E. coli at the same level as in the other G7 countries as of 2020; and to maintain the fluoroquinolone resistance of E. coli at the same level as in the other G7 countries as of 2020. A relatively unexplored facet of reducing AMR is the impact of minimizing transmission of AMR strains by companion animals. In this study we compared AMR rates in Staphylococcus intermedius group (SIG) and E. coli isolated from diseased companion animals in an animal hospital before and after restriction of antimicrobial use. Our study spanned a 4.5-year period from 2014 to June 2018 during which antimicrobial use was restricted in 2016. During this period, abundance of methicillin-resistant SIG isolates from the hospital dropped from 41.5% to 9.3%, and that of extended-spectrum ß-lactamase (ESBL)-producing E. coli isolates dropped from 29.5% to 9.5%. Tests for antimicrobial susceptibility revealed significantly reduced rates of AMR to enrofloxacin and levofloxacin in SIG isolates, and to cefazolin in E. coli isolates after antimicrobial use was restricted. Our observations suggest that restriction of antimicrobial use, especially that of third-generation cephalosporins and fluoroquinolones, is an effective method for reducing AMR rates. These findings will be relevant in guiding antimicrobial restriction approaches in other animal hospitals and clinics.

Correct species identification (reclassification in CNCTC) of strains of Staphylococcus intermedius-group can improve an insight into their evolutionary history.

A group of 59 putative strains of Staphylococcus intermedius/Staphylococcus pseudintermedius deposited in the Czech National Collection of Type Cultures (CNCTC, National Institute for Public Health, Prague, Czech Republic) and the National Reference Laboratory for Staphylococci (NRL for Staphylococci, National Institute for Public Health, Prague, Czech Republic) was reclassified using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). There the biggest human collection of S. pseudintermedius in Europe was analysed; 44 samples (75%) were of human origin. Twenty-two percent (n = 13) of the strains were isolated from animals, and two staphylococci were of unknown origin. This study revealed the prevalence of Staphylococcus pseudintermedius (94%, n = 53) vs. Staphylococcus intermedius (6%, n = 6) in the collection of human and veterinary staphylococci after reclassification. Results of PCR-RFLP analysis were verified by comparison with a repetitive element sequence-based polymerase chain reaction (Rep-PCR) analysis on 26 (44%) randomly selected strains. Due to a low-resolution ability of PCR-RFLP to separate Staphylococcus intermedius from Staphylococcus delphini, four isolates of Staphylococcus intermedius were biochemically verified further to exclude the presence of Staphylococcus delphini in the collection. Our results indicate that S. intermedius and S. pseudintermedius have occurred independently over an age-long period of their co-evolution.

Staphylococcus cornubiensis sp. nov., a member of the Staphylococcus intermedius Group (SIG).

We here describe a novel species in the Staphylococcus intermedius Group (SIG) which is phenotypically similar to Staphylococcus pseudintermedius but is genomically distinct from it and other SIG members, with an average nucleotide identity of 90.2 % with its closest relative S. intermedius. The description of Staphylococcus cornubiensis sp. nov. is based on strain NW1T (=NCTC 13950T=DSM 105366T) isolated from a human skin infection in Cornwall, UK. Although pathogenic, NW1T carries no known virulence genes or mobilizable antibiotic resistance genes and further studies are required to assess the prevalence of this species in humans as well as its potential presence in companion animals.

Bacteria isolated from companion animals in Japan (2014-2016) by blood culture.

We aimed to identify microorganisms isolated by blood culture (BC) from companion animals and to determine antimicrobial resistance of these isolates during 2014-2016 at veterinary laboratory, in comparison with those during 2010-2013, in Japan. Clinical data (animal species, visiting animals/hospitalized animals, and others except for disease type and clinical course including history of antimicrobial agent use) on ill animals at veterinary clinics or hospitals were obtained. We retrospectively analyzed animal-origin BC results extracted from the database in 2014-2016 and those obtained in 2010-2013. BC-positive samples were from most of dogs (n = 174 in 2014-2016 and n = 86 in 2010-2013). Escherichia coli (n = 50, 25.1%) and Staphylococcus intermedius group (SIG) bacteria (n = 23, 11.6%) were most prevalent in 2014-2016, while the percentages of E. coli (n = 22, 25.3%) and SIG (n = 9, 10.3%) in 2010-2013 were similar to those in 2014-2016. Percentages of extended-spectrum ß-lactamase (ESBL)-producing E. coli and methicillin-resistant staphylococci (MRS) rate of SIG bacteria isolated in 2014-2016 were 28.0% and 69.6% (vs. 22.7% and 44.4% in 2010-2013), respectively. Fourteen ESBL-producing E. coli in 2014-2016 were isolated from 7 visiting animals and 7 hospitalized ones, whereas the sixteen MRS of SIG were from 7 visiting animals and 9 hospitalized ones. Our observations support the prevalent microorganisms isolated by BC and their antimicrobial resistance patterns for two study periods.

Epidemiology, Clinical Characteristics, and Antimicrobial Susceptibility Profiles of Human Clinical Isolates of Staphylococcus intermedius Group.

The veterinary pathogens in the Staphylococcus intermedius group (SIG) are increasingly recognized as causes of human infection. Shared features between SIG and Staphylococcus aureus may result in the misidentification of SIG in human clinical cultures. This study examined the clinical and microbiological characteristics of isolates recovered at a tertiary-care academic medical center. From 2013 to 2015, 81 SIG isolates were recovered from 62 patients. Patients were commonly ≥50 years old, diabetic, and/or immunocompromised. Documentation of dog exposure in the electronic medical record was not common. Of the 81 SIG isolates, common sites of isolation included 37 (46%) isolates from wound cultures and 17 (21%) isolates from respiratory specimens. Although less common, 10 (12%) bloodstream infections were documented in 7 unique patients. The majority of SIG (65%) isolates were obtained from polymicrobial cultures. In comparison to S. aureus isolates from the same time period, significant differences were noted in proportion of SIG isolates that were susceptible to doxycycline (74% versus 97%, respectively; P < 0.001), trimethoprim-sulfamethoxazole (65% versus 97%, respectively; P < 0.001), and ciprofloxacin (78% versus 59%, respectively; P < 0.01). Methicillin resistance (MR) was detected in 12 (15%) of 81 SIG isolates. All MR isolates detected by an oxacillin disk diffusion test would have been misclassified as methicillin susceptible using a cefoxitin disk diffusion test. Thus, SIG is recovered from human clinical specimens, and distinction of SIG from S. aureus is critical for the accurate characterization of MR status in these isolates.

Antimicrobial Susceptibility Monitoring of Bacterial Pathogens Isolated from Urinary Tract Infections in Dogs and Cats Across Europe: ComPath Results.

ComPath is a pan-European antimicrobial surveillance program collecting bacterial pathogens from dogs and cats not recently exposed to antimicrobials. We present minimum inhibitory concentration data obtained using Clinical and Laboratory Standards Institute methodology for 616 urinary tract infection (UTI) isolates collected between 2008 and 2010. In both dogs and cats, the most common pathogen was Escherichia coli (59.8% and 46.7%, respectively). Antimicrobial activity against E. coli in dogs and cats was similar with fluoroquinolone and trimethoprim/sulfamethoxazole susceptibility >90%. Ampicillin susceptibility was ∼80%. Staphylococcus intermedius Group isolates from dogs (67/437, 15.3%) had high antimicrobial susceptibility (>90%) toward beta-lactams, fluoroquinolones, and trimethoprim/sulfamethoxazole. Four canine isolates (6%) were oxacillin resistant, and harbored mecA. Proteus mirabilis from dogs (48/437, 11.0%) had high antimicrobial susceptibility (∼90%) to amoxicillin/clavulanic acid, enrofloxacin, and marbofloxacin and slightly lower susceptibility (∼80-85%) to ampicillin and orbifloxacin. Streptococcus canis isolates (35/437, 8.0%) from dogs were all susceptible to ampicillin and amoxicillin/clavulanic acid and >90% susceptible to marbofloxacin. Although resistance was not observed, high intermediate susceptibility was seen for both enrofloxacin (28.6%) and orbifloxacin (85.7%). Overall, antimicrobial in vitro activity appears to be high in UTI pathogens from dogs and cats with low multidrug resistance, although a lack of specific dog and cat breakpoints for important antimicrobials such as cefovecin, cephalexin, and ibafloxacin prevents analysis of susceptibility for these agents.

Pyogenic Ventriculitis and Ventricular Empyema associated with Staphylococcus pseudintermedius in a Puppy.

A 40-day-old male, blue heeler puppy with hindlimb ataxia, nystagmus, apathy, motor incoordination and hyperaesthesia of the forelimbs died 3 days after the onset of clinical signs. Significant gross findings included cerebellar herniation, cerebral oedema and dilation of the third and right lateral cerebral ventricles due to the accumulation of a purulent exudate. Histopathological examination revealed pyogenic ventriculitis and purulent meningoencephalitis. Pure colonies of a coagulase-positive Staphylococcus were isolated from the purulent cerebral exudate. A polymerase chain reaction assay that targeted the 16S rRNA gene of bacteria amplified the desired product from bacterial colonies. Direct sequencing revealed the organism to be Staphylococcus pseudintermedius. Phylogenetic analyses showed that the organism was antigenically similar to Staphylococcus intermedius and Staphylococcus delphini, being part of the S. intermedius group of bacteria. These findings confirmed the participation of S. pseudintermedius in the development of the pathological manifestations and lesions observed in this puppy.

Treatment of a perforating thoracic bite wound in a dog with negative pressure wound therapy.

CASE DESCRIPTION A 4-year-old male Dachshund was examined following a bite attack that had occurred 5 days previously. The dog had acutely deteriorated despite IV antimicrobial treatment and fluid therapy. CLINICAL FINDINGS On initial examination, the patient was recumbent with signs of septic shock and a flail chest. Three penetrating wounds in the left thoracic wall with malodorous discharge were evident. The animal trauma triage score was 8 out of 18. Thoracic and abdominal radiography revealed displaced fractures of the left seventh, eighth, and ninth ribs and extensive subcutaneous emphysema. Additionally, a marked diffuse bronchointerstitial pattern, areas of alveolar pattern, and pneumothorax were present bilaterally. TREATMENT AND OUTCOME Open surgical debridement with left lateral lung lobectomy and resection of portions of the left thoracic wall were performed. Extensive soft tissue loss precluded primary reconstruction. The defect was stabilized with a polypropylene mesh implant, and negative pressure wound therapy (NPWT) at -100 mm Hg was initiated. Microbial culture and susceptibility testing of tissue samples indicated the presence of multidrug-resistant Staphylococcus pseudintermedius. The NPWT dressing was changed 2, 5, and 7 days after surgery. Treatment was well tolerated, and the mesh was completely covered with granulation tissue 10 days after surgery. On follow-up 5, 7, 12, and 19 months after surgery, the dog was clinically normal with no apparent complications. CLINICAL RELEVANCE Findings suggested that NPWT may be a valuable adjunct when treating small animal patients with severe thoracic trauma.

Biofilm-Associated Gene Expression in Staphylococcus pseudintermedius on a Variety of Implant Materials.

OBJECTIVE: To evaluate the expression of biofilm-associated genes in Staphylococcus pseudintermedius on multiple clinically relevant surfaces. STUDY DESIGN: In vitro experimental study. SAMPLE POPULATION: Two strains of methicillin-resistant S. pseudintermedius isolated from clinical infections representing the most common international isolates. METHODS: A quantitative polymerase chain reaction (qPCR) assay for expression of genes related to biofilm initial adhesion, formation/maturation, antimicrobial resistance, and intracellular communication was developed and validated. S. pseudintermedius biofilms were grown on 8 clinically relevant surfaces (polymethylmethacrylate, stainless steel, titanium, latex, silicone, polydioxanone, polystyrene, and glass) and samples of logarithmic and stationary growth phases were collected. Gene expression in samples was measured by qPCR. RESULTS: Significant differences in gene expression were identified between surfaces and between bacterial strains for most gene/strain/surface combinations studied. Expression of genes responsible for production of extracellular matrix were increased in biofilms. Expression of genes responsible for initial adhesion and intracellular communication was markedly variable. Antimicrobial resistance gene expression was increased on multiple surfaces, including stainless steel and titanium. CONCLUSION: A method for evaluation of expression of multiple biofilm-associated genes in S. pseudintermedius was successfully developed and applied to the study of biofilms on multiple surfaces. Variations in expression of these genes have a bearing on understanding the development and treatment of implant-associated biofilm infections and will inform future clinical research.

Gastrointestinal stromal tumor as entry port for S. intermedius causing bacteremia and multiple liver abscesses. Case report and review of literature.

We report a case of a previously healthy 52-year-old man who presented with fever and liver lesions suspicious for metastatic disease, which proved subsequently to be abscesses. Further workup revealed a gastrointestinal stromal tumor (GIST) in the gastric corpus as entry port to Streptococcus intermedius-associated bacteremia and liver abscesses. After antibiotic treatment and surgical resection of the tumor, the patient recovered well. This unusual case indicates that gastrointestinal stromal tumors can remain undetected until they cause a life threatening infection. A review of recent literature pertaining to GIST and liver abscesses follows.

Characterization of Staphylococcus pseudintermedius isolated from diseased dogs in Lithuania.

The aim of this study was to characterize Staphylococcus pseudintermedius for its antimicrobial resistance and virulence factors with a special focus on methicillin-resistant (MRSP) strains isolated from sick dogs in Lithuania. Clinically sick adult dogs suffering from infections (n=214) and bitches with reproductive disorders (n=36) from kennels were selected for the study. Samples (n=192) from the 250 tested (76.8%) dogs were positive for Staphylococcus spp. Molecular profiling using the species-specific nuc gene identified 51 isolates as S. pseudintermedius (26.6% from a total number of isolated staphylococci) of which 15 isolates were identified as MRSP. Ten MRSP isolates were isolated from bitches with reproductive disorders from two large breeding kennels. Data on susceptibility of S. pseudintermedius to different antimicrobials revealed that all isolates were susceptible to vancomycin, daptomycin and linezolid. Two isolates (3.9%) were resistant to rifampicin. A high resistance was seen towards penicillin G (94.1%), tetracycline (64.7%) and macrolides (68.7%). Resistance to fluoroquinolones ranged from 25.5% (gatifloxacin) to 31.4% (ciprofloxacin). The most prevalent genes encoding resistance included blaZ, aac(6')-Ie-aph(2'')-Ia, mecA, and tet(M). The Luk-I gene encoding a leukotoxin was detected in 29% of the isolates, whereas the siet gene encoding exfoliative toxin was detected in 69% of the S. pseudintermedius isolates. This report of MRSP in companion animals represents a major challenge for veterinarians in terms of antibiotic therapy and is a concern for both animal and public health.

In Vitro Antimicrobial Susceptibility of Staphylococcus pseudintermedius Isolates of Human and Animal Origin.

MIC results for 115 Staphylococcus intermedius group isolates are presented. Of these, 33% were methicillin resistant, among which 51.4% were susceptible to doxycycline, 29.7% to clindamycin, and 21.6% to trimethoprim-sulfamethoxazole. All of the isolates were susceptible to ceftaroline, daptomycin, linezolid, nitrofurantoin, quinupristin-dalfopristin, rifampin, tigecycline, and vancomycin. Of all the isolates, 82.6%, 67.8%, and 23.5% were susceptible to ciprofloxacin, erythromycin, and penicillin, respectively. No isolates harbored mupA or qacA/B genes, which suggested a lack of resistance to mupirocin or chlorhexidine.