A Comparison of the Minimum Inhibitory Concentration of Antibiotics in Staphylococcus Species Isolated From Orthopedic and Respiratory Medicine Infections.

INTRODUCTION: Antibiotic susceptibility is very important for the successful treatment of orthopedic infections, particularly for implant-related infections. While the minimum inhibitory concentrations (MICs) of Staphylococcus species were well investigated for the isolates from the respiratory tract, investigations for orthopedic pathogens are very limited. We investigated the antibiotic MIC values of Staphylococcus species isolated from orthopedic infections and compared them with those of respiratory medicine isolates used as a control. METHODS: The MICs of vancomycin (VCM), arbekacin (ABK), teicoplanin (TEIC), linezolid (LZD), and rifampicin (RFP) of a total of consecutive 259 (89 orthopedic and 170 respiratory) Staphylococcus speciesisolated in our laboratory from January 2013 to July 2016 were retrospectively reviewed. Differences between the MICs of each antibiotic in orthopedic and respiratory samples were determined. RESULTS: The number of methicillin-sensitive Staphylococcus aureus (MSSA) with a VCM MIC of <0.5 µg/mL among respiratory isolates was significantly higher than that among orthopedic isolates, while those with a MIC of 2 µg/mL were significantly lower (P = 0.0078). The proportion of methicillin-resistant coagulase-negative staphylococci (MRCNS) isolates with a VCM MIC of 2 µg/mL was significantly higher in orthopedic samples than that of methicillin-resistant Staphylococcus aureus (MRSA) (P < 0.001) in respiratory isolates. The proportion of MRCNS orthopedic isolates with an RFP MIC of >2 µg/mL was significantly higher (P = 0.0058) than that of other orthopedic staphylococci. CONCLUSIONS: The VCM MICs of Staphylococcus species from orthopedic infections were higher than those of respiratory samples, particularly MRCNS from implant-related samples.

Antimicrobial efficacy of Thymus vulgaris extract against some Staphylococcus species isolated from subclinical mastitis in cattle in Basrah province, Iraq.

Background: Thymus vulgaris extracts can play a significant role as alternatives for antimicrobial agents against bovine staphylococcus mastitis. Aim: This research's goal was to evaluate the antibacterial properties of an extract from T. vulgaris as an alternative to antibiotics for bovine Staphylococcus mastitis. In addition, it is important to know the effect of the extraction methods (hot alcoholic, cold alcoholic, and hot water extract) on their effectiveness. Methods: Two hundred ten cow milk samples from different areas of Basrah province had been suffering subclinical mastitis reported by using the California mastitis test (CMT). Staphylococcus species were identified by conventional microbiological technique, GP24 Kit, and nuc gene. Antimicrobial activity of various concentrations of T. vulgaris extracted (75, 50, 25) mg/ml with different methods of extraction (hot alcoholic, cold alcoholic, and hot water extract). Results: Out of 210 samples, 99 (47.1%) were positive for the CMT, and the identification rate of Staphylococci spp. by conventional microbiological technique and GP24 kit was 78 (78.8%). Out of 78 isolates of Staphylococcus spp. 48 (61.5%) were identified as Staphylococcus aureus, by using both molecular techniques using PCR and miniaturized Kit GP24 and employing the miniature GP24, the remaining 30 (38.5%) were determined to be different species of Staphylococcus. Antibacterial activity of various concentrations of T. vulgaris extracted (75, 50, 25) mg/ml with different methods of extraction revealed that hot alcoholic extract (100%) was more effective than cold alcoholic extract (66.7%), whereas there is no effect on the bacteria species with the hot water extract. Conclusion: Thymus vulgaris extracts can play a significant role as alternatives for antimicrobial agents against bovine staphylococcus mastitis.

Dynamics of antimicrobial resistance and virulence of staphylococcal species isolated from foods traded in the Cape Coast metropolitan and Elmina municipality of Ghana.

The impact of staphylococci on food poisoning and infections could be higher than previously reported. In this study, we characterised the occurrence and coexistence of antimicrobial resistance and virulence genes of staphylococci isolates in foods. Staphylococci were isolated from 236 samples of selected street-vended foods and identified. The pattern of antimicrobial resistance and virulence genes in the staphylococci were assessed using disc diffusion, PCR and analysis of next-generation sequencing data. The food samples (70.76 %) showed a high prevalence of staphylococci and differed among the food categories. Forty-five Staphylococcus species were identified and comprised coagulase-negative and positive species. Staphylococcus sciuri (now Mammaliicoccus sciuri), S. aureus, S. kloosii, S. xylosus, S. saprophyticus, S. haemolyticus and S. succinus were the most abundant species. The staphylococcal isolates exhibited resistance to tetracycline, levofloxacin, ciprofloxacin, norfloxacin, gentamicin and amikacin and susceptibility to nitrofurantoin. Antimicrobial susceptibilities were also reported for cefoperazone, ceftriaxone, cefotaxime, nalidixic acid and piperacillin-tazobactam. The antimicrobial resistance and virulence genes commonly detected consisted of tet, arl, macB, van, gyr, nor, optrA, bcrA, blaZ, taeA and S. aureus lmrS. The isolates frequently exhibited multiple resistance (30.42 %) of up to eight antimicrobial drug classes. The isolates predominantly harboured genes that express efflux pump proteins (50.53 %) for antibiotic resistance compared with inactivation (10.05 %), target alteration (26.72 %), protection (7.67 %) and replacement (3.17 %). The virulence determinants comprised genes of pyrogenic toxin superantigens (eta, etb, tst), adhesions (clf, fnbA, fnbB, cna, map, ebp, spA, vWbp, coa) and genes that express exoproteins (nuclease, metalloprotease, γ-hemolysin, hyaluronate lyase). There was a statistically significant difference in the prevalence of staphylococci isolates and their antimicrobial resistance and virulence profile as revealed by the phenotypic, PCR and next-generation sequencing techniques. The findings suggest a higher health risk for consumers. We recommend a critical need for awareness and antimicrobial susceptibility and anti-virulence strategies to ensure food safety and counteract the spread of this clinically relevant genus.

Screening of the novel antimicrobial drug, XF-73, against 2,527 Staphylococcus species clinical isolates.

XF-73 (exeporfinium chloride) is a synthetic, di-cationic porphyrin derivative with rapid, potent bactericidal properties and a low propensity for engendering bacterial resistance. It is being developed clinically for the decolonization of Staphylococcus aureus in the nasal cavity to prevent post-operative staphylococcal infections. This study reports the minimum inhibitory concentration (MIC) of XF-73 in comparison to 22 antibiotics against a panel of >2,500 clinical isolates composed of 16 different Coagulase-positive and -negative Staphylococcus species from 33 countries. XF-73 was found to be effective against all isolates tested, with MICs ranging between ≤0.12 - 4 µg/ml (MIC50 and MIC90 values of 0.5 and 1 µg/ml respectively). XF-73 was found to be equally effective against antibiotic resistant isolates as antibiotic sensitive isolates, with no impact of pre-existing antibiotic resistance mechanisms to cell wall synthesis inhibitors (ß-lactams, carbapenems, glycopeptides and cephalosporins), protein synthesis inhibitors (oxazolidinones, macrolides and tetracyclines), DNA synthesis inhibitors (fluoroquinolones) and a folate synthesis inhibitor. The panel selected also included examples of multidrug-resistant S. aureus isolates and, in all cases, the XF-73 MIC ranges were found to be similar against each of these groups. This dataset expands the knowledge of the breadth of activity of this novel antibacterial against a wide range of global S. aureus isolates and supports the potential utility of XF-73 for the treatment of patients who are S. aureus nasal carriers. Similar results were also obtained for multidrug-resistant isolates of other Staphylococcus species included in the study and collectively support the continued clinical development of XF-73 as an effective anti-staphylococcal drug.

Prosthetic knee joint infection caused by α-hemolytic Streptococcus species: a case report.

BACKGROUND: Knee arthroplasty is an orthopedic surgical procedure in which a damaged joint is replaced with an artificial one. It is estimated that 1-2% of knee arthroplasties will encounter infection over their lifetime. Although α-hemolytic Streptococcus species play an important role in prosthetic joint infection, they are less common than staphylococcal species. CASE PRESENTATION: In this report, a 50-year-old Iranian woman was diagnosed with prosthetic knee joint infection based on clinical, radiological, and laboratory findings. She was diabetic and had undergone a left total knee arthroplasty, which, 18 months after the surgery, presented pain, erythema, and edema in that knee. The primary culture of knee aspirate was positive for α-hemolytic Streptococcus species, but following antibiotic medication, culture was negative. The primary antibiotic regime was vancomycin and meropenem, which was changed to cefepime for the management of the infection based on the results of antimicrobial susceptibility testing. CONCLUSIONS: This report indicated the clinical presentation and management of the patient with prosthetic joint infection in which the patient recovered without any severe complications or surgical intervention.

Antimicrobial activity of α-mangostin against Staphylococcus species from companion animals in vitro and therapeutic potential of α-mangostin in skin diseases caused by S. pseudintermedius.

Antimicrobial resistance in Staphylococcus species from companion animals is becoming increasingly prevalent worldwide. S. pseudintermedius is a leading cause of skin infections in companion animals. α-mangostin (α-MG) exhibits various pharmacological activities, including antimicrobial activity against G (+) bacteria. This study investigated the antimicrobial activity of α-MG against clinical isolates of Staphylococcus species from companion animals and assessed the therapeutic potential of α-MG in skin diseases induced by S. pseudintermedius in a murine model. Furthermore, the action mechanisms of α-MG against S. pseudintermedius were investigated. α-MG exhibited antimicrobial activity against clinical isolates of five different Staphylococcus species from skin diseases of companion animals in vitro, but not G (-) bacteria. α-MG specifically interacted with the major histocompatibility complex II analogous protein (MAP) domain-containing protein located in the cytoplasmic membrane of S. pseudintermedius via hydroxyl groups at C-3 and C-6. Pretreatment of S. pseudintermedius with anti-MAP domain-containing protein polyclonal serum significantly reduced the antimicrobial activity of α-MG. The sub-minimum inhibitory concentration of α-MG differentially regulated 194 genes, especially metabolic pathway and virulence determinants, in S. pseudintermedius. α-MG in pluronic lecithin organogel significantly reduced the bacterial number, partially restored the epidermal barrier, and suppressed the expression of cytokine genes associated with pro-inflammatory, Th1, Th2, and Th17 in skin lesions induced by S. pseudintermedius in a murine model. Thus, α-MG is a potential therapeutic candidate for treating skin diseases caused by Staphylococcus species in companion animals.

Prevalence of Staphylococcus spp. from human specimens submitted to diagnostic laboratories in South Africa, 2012-2017.

Background: Although staphylococci are commensals of the skin and mucosa of humans and animals, they are also opportunistic pathogens. Some coagulase-negative Staphylococcus spp. (CoNS), such as S. haemolyticus and S. epidermidis, are reported to be zoonotic. Objectives: The prevalence of coagulase positive (CoPS), CoNS and coagulase-variable Staphylococcus spp. isolated from human clinical cases in South Africa was investigated. Method: Retrospective records of 404 217 diagnostic laboratory submissions from 2012 to 2017 were examined and analysed in terms of time, place and person. Results: Of the 32 different species identified, CoPS were the most frequently isolated (74.7%), followed by CoNS (18.9%). Just over half (51.2%) of the Staphylococcus isolates were from males, while females contributed 44.8%. Patients aged 0-4 years contributed the most (21.5%) isolates, with the highest number coming from KwaZulu-Natal (32.8%). Urinary specimens accounted for 29.8% of the isolates reported. There was no variation in the number of Staphylococcus isolates reported in the autumn (25.2%), winter (25.2%), spring (25.1%) and summer (24.5%) seasons. Conclusion: This study demonstrated the diversity of Staphylococcus spp. isolated from humans and the magnitude of infection, with the most predominant species being S. aureus and S. epidermidis. Contribution: Although most isolates were CoPS, the isolation of CoNS seen in this study suggests a need to improve infection control measures in a South African context. More research is needed to investigate the determinants of the observed variations in the study.

Antimicrobial Resistance of Staphylococci at Animal Human Interface in Smallholders and Dairy Farms in Central Oromia, Ethiopia.

Purpose: Staphylococcus species come from a variety of sources and can contaminate milk during milking, cause mastitis and other diseases in animals and humans. The enterotoxins they produce cause food poisoning. Our objectives were to isolate, biochemically characterize, and determine antimicrobial susceptibility profiles of Staphylococcus species from dairy farms in central Oromia, Ethiopia. Methods: A total of 339 samples (n = 135 [raw milk], n = 135 [udders' swabs], n = 25 [milkers' hands swabs], n = 44 [pooled milking utensils' swabs]) were collected from smallholders and dairy farms. Bacteriological culture and biochemical tests were performed to isolate and identify Staphylococcus species, and the Kirby Bauer disk diffusion method was used for antimicrobial susceptibility testing. Results: Across all sample types and dairy farms, 247 (72.9%) Staphylococcus isolates were obtained which comprised of 101 (74.8%) isolates from raw milk, 98 (72.6%) from udder swabs, 30 (68.2%) from pooled utensil swabs, and 18 (72%) from milkers' hand swabs. Fifty coagulase-positive Staphylococcus isolates (20 S. aureus, 20 S. hyicus and 10 S. intermedius) subjected to antimicrobial susceptibility tests have shown various degrees of resistance. All S. aureus isolates were 100% resistant to ampicillin and penicillin. Out of 20 S. hyicus isolates, 90% were resistant to ampicillin and 85% to penicillin. S. intermedius isolates (n=10) were 70% resistant to nalidixic acid and penicillin whilst remaining 100% resistant to ampicillin. Five S. aureus, three S. intermedius and two S. hyicus isolates from raw milk, milk utensil swabs and milkers' hand swabs were multidrug-resistant (resistance to at least three classes of antimicrobials). Conclusion: This study revealed a high prevalence of staphylococci in the dairy cattle, milkers and milking utensils with multidrug-resistant coagulase-positive Staphylococcus species suggesting the significance of pasteurization. Further research is encouraged on the factors leading to antibiotic resistance in Staphylococcus species.

Compositional Alterations of the Nasal Microbiome and Staphylococcus aureus-Characterized Dysbiosis in the Nasal Mucosa of Patients With Allergic Rhinitis.

OBJECTIVES: Host-microbial commensalism can shape the innate immune response in the nasal mucosa, and the microbial characteristics of nasal mucus directly impact the mechanisms of the initial allergic responses in the nasal epithelium. We sought to determine alterations of the microbial composition in the nasal mucus of patients with allergic rhinitis (AR) and to elucidate the interplay between dysbiosis of the nasal microbiome and allergic inflammation. METHODS: In total, 364,923 high-quality bacterial 16S ribosomal RNA-encoding gene sequence reads from 104 middle turbinate mucosa samples from healthy participants and patients with AR were obtained and analyzed using the Quantitative Insights into Microbial Ecology pipeline. RESULTS: We analyzed the microbiota in samples of nasal mucus from patients with AR (n=42) and clinically healthy participants (n=30). The Proteobacteria (Ralstonia genus) and Actinobacteria (Propionibacterium genus) phyla were predominant in the nasal mucus of healthy subjects, whereas the Firmicutes (Staphylococcus genus) phylum was significantly abundant in the nasal mucus of patients with AR. In particular, the Ralstonia genus was significantly dominant in the clinically healthy subjects. Additional pyrosequencing data from 32 subjects (healthy participants: n=15, AR patients: n=17) revealed a greater abundance of Staphylococcus epidermidis, Corynebacterium accolens, and Nocardia coeliaca, accounting for 41.55% of mapped sequences in the nasal mucus of healthy participants. Dysbiosis of the nasal microbiome was more pronounced in patients with AR, and Staphylococcus aureus exhibited the greatest abundance (37.69%) in their nasal mucus, in association with a positive response to house dust mites and patients' age and height. CONCLUSION: This study revealed alterations in the nasal microbiome in the nasal mucus of patients with AR at the levels of microbial genera and species. S. aureus-dominant dysbiosis was distinctive in the nasal mucus of patients with AR, suggesting a role of host-microbial commensalism in allergic inflammation.

Epidemiology of staphylococci species and their antimicrobial-resistance among patients with wound infection in Ethiopia: a systematic review and meta-analysis.

OBJECTIVES: The aim of this study was to determine the pooled estimate of Staphylococcus aureus and coagulase negative staphylococci and their antimicrobial-resistance in patients with wound infection. METHODS: Literature searches were carried out in the electronic biomedical databases and indexing services such as PubMed/MEDLINE, EMBASE, Science Direct, Web of Science and Google Scholar. Original records of research articles, available online from 1988 to March 2020, addressing the rates and antimicrobial-resistance pattern of staphylococcus aureus (S. aureus) and coagulase negative staphylococci (CoNS) in patients with wound infection were identified and screened. Endnote citation manager software version X9 for windows was utilized to collect and organize search outcomes and for removal of duplicate articles. The relevant data were extracted from included studies using a format prepared in Microsoft Excel and exported to STATA 14.0 software for the outcome measures analyses and subgrouping. RESULTS: The electronic databases search yielded 378 studies, of which 39 met predefined inclusion criteria and included in the final analyses. The pooled estimate of wound infection was 36% [95% CI: 23-50%) for S. aureus and 12% [95% CI: 9-14%) for CoNS. S. aureus exhibited a higher rate of resistance to penicillin (84%), ampicillin (83%), amoxicillin (67%), methicillin (50%), cotrimoxazole (50%), tetracycline (61%), doxycycline (58%), chloramphenicol (49%) and erythromycin (45%). However, relative lower resistant rate was observed to Augmentin (amoxicillin-clavulanic acid) (35%), gentamicin (33%), norfloxacin (23%), ciprofloxacin (26%), ceftriaxone (36%), vancomycin (29%) and clindamycin (40%). Similarly, for CoNS there was high resistance to methicillin, 52% [95% CI: 26-78%]) and other antibiotics, but lower resistance to clindamycin, 15% [95% CI: 6-24]) and vancomycin, 22% [95% CI: 2-41%]). Ceftriaxone resistance was observed with prevalence of 36% [95% CI: 21-50%] for S. aureus and 42% [95% CI: 29-55%] for CoNS. CONCLUSION: There was high resistance of staphylococci bacterial species to commonly used antimicrobials in the clinical settings in Ethiopia. It is a high time to implement multitude strategies to contain the threat. Further research focusing on factors promoting resistance and the effect of resistance on treatment outcome studies on these virulent organisms are warranted.

Metabolic potential of microbial community and distribution mechanism of Staphylococcus species during broad bean paste fermentation.

Although the microbial diversity and structure in bean-based fermented foods have been widely studied, systematic studies on functional microbiota and mechanism of community forms in multi-microbial fermentation systems were still lacking. In this work, the metabolic pathway and functional potential of microbial community in broad bean paste (BBP) were investigated by metagenomics approach, and Staphylococcus, Bacillus, Weissella, Aspergillus and Zygosaccharomyces were found to be the potential predominant populations responsible for substrate alteration and flavor biosynthesis. Among them, Staphylococcus was the most abundant and widespread functional microbe, and closely related Staphylococcus species were diverse and ubiquitously distributed, with the opportunistic pathogen S. gallinarum being the most abundant Staphylococcus specie isolated from BBP. To explain the dominance status of S. gallinarum and species distributions of Staphylococcus genus, we tested the effects of abiotic and biotic factors on three Staphylococcus species using a tractable BBP model, demonstrating that adaptation to environmental conditions (environmental parameters and other functional microbes) led to the dominant position and species coexistence of Staphylococcus, and congeneric competition among Staphylococcus species further shaped ecological distributions of closely related Staphylococcus species. In general, this work revealed the metabolic potential of microbial community and distribution mechanism of Staphylococcus species during BBP fermentation, which could help traditional factories to more precisely control the safety and quality of bean-based fermented foods.

An Understanding of the Global Status of Major Bacterial Pathogens of Milk Concerning Bovine Mastitis: A Systematic Review and Meta-Analysis (Scientometrics).

In this study, the major mastitis pathogen prevalence in the cattle and buffalo of the world was estimated by a meta-analysis. Staphylococcus (S) species, Streptococcus (St) species, and Escherichia coli (Ec) prevalence studies reported during 1979-2019 were collected using online databases, and offline resources. A meta-analysis of these data was done with the meta package in R-Software. The Staphylococcus aureus was the major mastitis pathogen, mostly causing subclinical mastitis, Ec causing clinical mastitis and St causing subclinical and clinical mastitis. The pooled prevalence estimates of S, St, and Ec were 28%, 12%, and 11% in the world from 156, 129, and 92 studies, respectively. The S, St, and Ec prevalences were high in Latin America (51%), Oceania (25%), and Oceania (28%), respectively. Higher S, St, and Ec prevalences were observed by molecular methods, signifying high sensitivity and usefulness for future studies. Among bacterial species, S. aureus (25%) followed by coagulase-negative Staphylococcus species (20%), Escherichia coli (11%), St. agalactiae (9%), St. uberis (9%) were the important pathogens present in the milk of the world. We hypothesize that there is a urgent need to reduce mastitis pathogen prevalence by ensuring scientific farm management practices, proper feeding, therapeutic interventions to augment profits in dairying, and improving animal and human health.

Antimicrobial sensitivity patterns of Staphylococcus species isolated from mobile phones and implications in the health sector.

OBJECTIVES: The aim of this research was to determine drug sensitivity profiles of Staphylococcus species isolated from mobile phones of students in Microbiology and Biomedical Laboratory Sciences from UZIMA University, Kisumu (Kenya) and the University Colleges Leuven-Limburg, Leuven (Belgium), respectively. RESULTS: All mobile phones (16/16, 100%) had gram-positive bacteria. 3/8 (37.5%) mobile devices had Staphylococcus aureus. 2/3 (67%) Staphylococcus aureus strains were resistant to ampicillin, oxacillin, ceftazidime, vancomycin and amoxicillin. Guidelines for disinfection of mobile phones need to be developed urgently to stop transmission of resistant bacteria.

Characterization of Antibiotic and Biocide Resistance Genes and Virulence Factors of Staphylococcus Species Associated with Bovine Mastitis in Rwanda.

The present study was conducted from July to August 2018 on milk samples taken at dairy farms in the Northern Province and Kigali District of Rwanda in order to identify Staphylococcus spp. associated with bovine intramammary infection. A total of 161 staphylococcal isolates originating from quarter milk samples of 112 crossbred dairy cattle were included in the study. Antimicrobial susceptibility testing was performed and isolates were examined for the presence of various resistance genes. Staphylococcus aureus isolates were also analyzed for the presence of virulence factors, genotyped by spa typing and further phenotypically subtyped for capsule expression using Fourier Transform Infrared (FTIR) spectroscopy. Selected S. aureus were characterized using DNA microarray technology, multi-locus sequence typing (MLST) and whole-genome sequencing. All mecA-positive staphylococci were further genotyped using dru typing. In total, 14 different staphylococcal species were detected, with S. aureus being most prevalent (26.7%), followed by S. xylosus (22.4%) and S. haemolyticus (14.9%). A high number of isolates was resistant to penicillin and tetracycline. Various antimicrobial and biocide resistance genes were detected. Among S. aureus, the Panton-Valentine leukocidin (PVL) genes, as well as bovine leukocidin (LukM/LukF-P83) genes, were detected in two and three isolates, respectively, of which two also carried the toxic shock syndrome toxin gene tsst-1 bovine variant. t1236 was the predominant spa type. FTIR-based capsule serotyping revealed a high prevalence of non-encapsulated S. aureus isolates (89.5%). The majority of the selected S. aureus isolates belonged to clonal complex (CC) 97 which was determined using DNA microarray based assignment. Three new MLST sequence types were detected.

Distinct nasal airway bacterial microbiotas differentially relate to exacerbation in pediatric patients with asthma.

BACKGROUND: In infants, distinct nasopharyngeal bacterial microbiotas differentially associate with the incidence and severity of acute respiratory tract infection and childhood asthma development. OBJECTIVE: We hypothesized that distinct nasal airway microbiota structures also exist in children with asthma and relate to clinical outcomes. METHODS: Nasal secretion samples (n = 3122) collected after randomization during the fall season from children with asthma (6-17 years, n = 413) enrolled in a trial of omalizumab (anti-IgE) underwent 16S rRNA profiling. Statistical analyses with exacerbation as the primary outcome and rhinovirus infection and respiratory illnesses as secondary outcomes were performed. Using A549 epithelial cells, we assessed nasal isolates of Moraxella, Staphylococcus, and Corynebacterium species for their capacity to induce epithelial damage and inflammatory responses. RESULTS: Six nasal airway microbiota assemblages, each dominated by Moraxella, Staphylococcus, Corynebacterium, Streptococcus, Alloiococcus, or Haemophilus species, were observed. Moraxella and Staphylococcus species-dominated microbiotas were most frequently detected and exhibited temporal stability. Nasal microbiotas dominated by Moraxella species were associated with increased exacerbation risk and eosinophil activation. Staphylococcus or Corynebacterium species-dominated microbiotas were associated with reduced respiratory illness and exacerbation events, whereas Streptococcus species-dominated assemblages increased the risk of rhinovirus infection. Nasal microbiota composition remained relatively stable despite viral infection or exacerbation; only a few taxa belonging to the dominant genera exhibited relative abundance fluctuations during these events. In vitro, Moraxella catarrhalis induced significantly greater epithelial damage and inflammatory cytokine expression (IL-33 and IL-8) compared with other dominant nasal bacterial isolates tested. CONCLUSION: Distinct nasal airway microbiotas of children with asthma relate to the likelihood of exacerbation, rhinovirus infection, and respiratory illnesses during the fall season.

Machine Learning Analyses on Data including Essential Oil Chemical Composition and In Vitro Experimental Antibiofilm Activities against Staphylococcus Species.

Biofilm resistance to antimicrobials is a complex phenomenon, driven not only by genetic mutation induced resistance, but also by means of increased microbial cell density that supports horizontal gene transfer across cells. The prevention of biofilm formation and the treatment of existing biofilms is currently a difficult challenge; therefore, the discovery of new multi-targeted or combinatorial therapies is growing. The development of anti-biofilm agents is considered of major interest and represents a key strategy as non-biocidal molecules are highly valuable to avoid the rapid appearance of escape mutants. Among bacteria, staphylococci are predominant causes of biofilm-associated infections. Staphylococci, especially Staphylococcus aureus (S. aureus) is an extraordinarily versatile pathogen that can survive in hostile environmental conditions, colonize mucous membranes and skin, and can cause severe, non-purulent, toxin-mediated diseases or invasive pyogenic infections in humans. Staphylococcus epidermidis (S. epidermidis) has also emerged as an important opportunistic pathogen in infections associated with medical devices (such as urinary and intravascular catheters, orthopaedic implants, etc.), causing approximately from 30% to 43% of joint prosthesis infections. The scientific community is continuously looking for new agents endowed of anti-biofilm capabilities to fight S. aureus and S epidermidis infections. Interestingly, several reports indicated in vitro efficacy of non-biocidal essential oils (EOs) as promising treatment to reduce bacterial biofilm production and prevent the inducing of drug resistance. In this report were analyzed 89 EOs with the objective of investigating their ability to modulate bacterial biofilm production of different S. aureus and S. epidermidis strains. Results showed the assayed EOs to modulated the biofilm production with unpredictable results for each strain. In particular, many EOs acted mainly as biofilm inhibitors in the case of S. epidermidis strains, while for S. aureus strains, EOs induced either no effect or stimulate biofilm production. In order to elucidate the obtained experimental results, machine learning (ML) algorithms were applied to the EOs' chemical compositions and the determined associated anti-biofilm potencies. Statistically robust ML models were developed, and their analysis in term of feature importance and partial dependence plots led to indicating those chemical components mainly responsible for biofilm production, inhibition or stimulation for each studied strain, respectively.

High rate of neonates colonized by methicillin-resistant Staphylococcus species in an Intensive Care Unit.

INTRODUCTION: Staphylococcal colonization is a risk factor for healthcare-associated infections, which are frequent in Neonatal Intensive Care Units (NICU). This study analyzed microbiology, epidemiology and clinical aspects of Staphylococcus spp. colonizing neonates. METHODOLOGY: Nasal or periumbilical swabs were evaluated from 175 newborns admitted to a NICU of a Rio de Janeiro hospital from March to September 2009. Clinical data were obtained from the medical records. SCCmec typing and the mecA and Panton-Valentine Leukocidin (PVL) genes were detected by PCR. Clonal diversity was evaluated by pulsed-field gel electrophoresis. RESULTS: Staphylococcus spp. isolates were detected in 98 (56%) neonates, 66.3% of them had birth weight ≤ 2500 g, 62.2% were preterm (˂ 37 weeks) and the mean length of hospitalization was 14.9 days. Among the 133 isolates identified, 48.1% were S. epidermidis, 23.3% S. haemolyticus and 13.5% S. aureus. Methicillin-resistant Staphylococcus isolate was detected in 77.6% of neonates. The methicillin-resistant S. aureus isolates carried the SCCmec type IV, while 94.6% of S. epidermidis and 85.7% of S. haemolyticus presented non-typeable cassettes. Among the S. aureus, 55.6% had PVL genes and the USA800 genotype was prevalent. Two genotypes of S. epidermidis and one of S. haemolyticus clustered 42.2% and 25.8% of the isolates, respectively. S haemolyticus colonization was associated with the use of parenteral nutrition and mechanical ventilation. CONCLUSION: High rate of neonates colonized by methicillin-resistant Staphylococcus species and the permanence of clones circulating in the NICU highlight the importance for continuous and preventive surveillance in this high-risk population.

Acute-phase inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4) levels in serum and milk of cows with subclinical mastitis caused by Streptococcus species and coagulase-negative Staphylococcus species.

The aim of the study was to investigate the concentrations of acute-phase inter-α-trypsin inhibitor heavy chain 4 (ITIH4) in serum and milk of cows with subclinical mastitis caused by Streptococcus spp. (STR) and coagulase-negative Staphylococcus spp. (CNS) and healthy cows. The blood and milk samples were obtained from 60 mid-lactation, multiparous Holstein-Friesian cows from 7 herds in the Lublin region of Poland. In the milk samples from 40 cows with subclinical mastitis, Streptococcus spp. and CNS were isolated. The ITIH4 was significantly higher in serum of cows with subclinical mastitis caused both by STR and CNS compared with healthy cows. One hundred percent of animals infected with Streptococcus spp. and 89% of animals infected with Staphylococcus spp. showed ITIH4 concentration in sera higher than 0.5 mg/mL. The concentration of ITIH4 in milk also was significantly higher in cows with subclinical mastitis caused by Streptococcus spp. and Staphylococcus spp. compared with the control group. Seventy percent of cows infected by STR and CNS showed ITIH4 concentration in milk higher than 2.5 µg/mL. Milk ITIH4 concentration higher than 5 µg/mL was found in 55% of animals infected with Streptococcus spp. and in 40% of animals infected with Staphylococcus spp. No statistically significant differences were observed in ITIH4 concentrations both in serum and in milk between the studied unhealthy animal groups. These results suggest that ITIH4 may be used in the future as a novel diagnostic marker in serum and in milk of subclinical mastitis in cows.

Pathological Changes in Experimental Intramammary Infection with Different Staphylococcus Species in Mice.

INTRODUCTION: Mastitis is caused by different Staphylococcus species, produce great economic loss to farmers. Present study was conducted to know pathological changes in mice inoculated with Staphylococcus epidermidis, S. chromogenes, S. haemolyticus and S. aureus isolated from bovine milk. MATERIALS AND METHODS: Mice were inoculated with 50 µl (2x104 cfu organisms) per mammary gland and euthanized at 6, 12, 24, 48, 72 and 96 h. Mammary gland weight, gross and histopathological changes of mammary gland, liver, kidney, spleen, heart, lung and inguinal lymph node were studied. RESULTS: Mammary gland weight and percentage of body weight increased at 6 and 96 h in S. aureus and S. haemolyticus infected mice. Gross changes were observed in mammary gland but not in other organs. Mammary gland revealed gross changes from 24 to 72 h in three Coagulase negative staphylococcal (CNS) species and persisted up to 96 h in S. aureus infected mice. Histopathological changes in mammary glands was severe in S. aureus and moderate in CNS species. S. aureus infected mice revealed severe damage to alveoli and loss of alveolar architecture at 96 h but three CNS species infection was overcome by host factors which was evident by proliferation of alveolar epithelial cells. No histological changes were observed in kidney, spleen, lung, heart and inguinal lymph nodes. CONCLUSIONS: S. aureus caused severe mastitis in mice when compared to CNS species. Further, it is first report of mice to study CNS mastitis, and in future it can be used as model for CNS mastitis.

Colony Fingerprint-Based Discrimination of Staphylococcus species with Machine Learning Approaches.

Detection and discrimination of bacteria are crucial in a wide range of industries, including clinical testing, and food and beverage production. Staphylococcus species cause various diseases, and are frequently detected in clinical specimens and food products. In particular, S. aureus is well known to be the most pathogenic species. Conventional phenotypic and genotypic methods for discrimination of Staphylococcus spp. are time-consuming and labor-intensive. To address this issue, in the present study, we applied a novel discrimination methodology called colony fingerprinting. Colony fingerprinting discriminates bacterial species based on the multivariate analysis of the images of microcolonies (referred to as colony fingerprints) with a size of up to 250 µm in diameter. The colony fingerprints were obtained via a lens-less imaging system. Profiling of the colony fingerprints of five Staphylococcus spp. (S. aureus, S. epidermidis, S. haemolyticus, S. saprophyticus, and S. simulans) revealed that the central regions of the colony fingerprints showed species-specific patterns. We developed 14 discriminative parameters, some of which highlight the features of the central regions, and analyzed them by several machine learning approaches. As a result, artificial neural network (ANN), support vector machine (SVM), and random forest (RF) showed high performance for discrimination of theses bacteria. Bacterial discrimination by colony fingerprinting can be performed within 11 h, on average, and therefore can cut discrimination time in half compared to conventional methods. Moreover, we also successfully demonstrated discrimination of S. aureus in a mixed culture with Pseudomonas aeruginosa. These results suggest that colony fingerprinting is useful for discrimination of Staphylococcus spp.