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Multi-drug resistance traits of Staphylococcus species especially methicillin-resistant Staphylococcus aureus (MRSA) in the clinical settings are well established. Of environmental concern is hospital effluents discharging into wastewaters. This article investigated the prevalence and detection of antibiotic resistance genes in Staphylococcus species from clinical and environmental sources in Ile-Ife, Nigeria. Standard culture-based and molecular protocols were used. Seventy-six (27 clinical, 14 hospital effluent and 35 environmental) Staphylococcus isolates were recovered: 56.58% were coagulase-negative and 43.42% coagulase-positive (S. aureus). For the clinical isolates, 10, 6, 4, 4 and 1 were isolated from urine, skin, wounds, blood and pus, respectively. Isolates were resistant to methicillin and amoxycillin (91.7%), cloxacillin (88.0%), ciprofloxacin (84.0%), ofloxacin (83.3%), azithromycin (78.0%), ceftazidime (76.0%), gentamycin (75.0%), cefuroxime (75.0%) and erythromycin (72.0%). Nearly, all isolates (90.8%) had multiple antibiotic resistance (MAR) index >0.2. Overall MAR indices for Staphylococcus species isolated from the clinical, hospital effluent and environmental wastewaters were relatively similar (0.482; 0.500; 0.435). mecA, nuc and luk-pvl genes were detected in S. aureus, while mecA was detected in S. arlettae, S. sciuri, S. cohnii, S. epidermidis and S. saprophyticus. This study informs on the potential contamination of environmental waters downstream from hospitals and possible impacts that this could have on human and animal health.

Background/Objectives: Infections in dogs caused by methicillin-resistant staphylococci (MRS) present limited treatment options. This study’s objective was to investigate the molecular epidemiology of Staphylococcus spp. cultured exclusively from clinical canine skin and ear samples in Queensland, Australia, using whole-genome sequencing (WGS). Methods: Forty-two Staphylococcus spp. isolated from clinical canine skin and ear samples, from an unknown number of dogs, were sourced from two veterinary diagnostic laboratories between January 2022 and May 2023. These isolates underwent matrix-assisted laser desorption ionisation– time of flight bacterial identification, minimum inhibitory concentration testing using SensititreTM plates and WGS. Phylogenetic trees and core genome multilocus sequence typing (cgMLST) minimum spanning trees (MSTs) were constructed. Results: The isolates included methicillin-resistant and -sensitive S. pseudintermedius (MRSP: 57.1%, 24/42; and MSSP: 19.1%, 8/42), methicillin-resistant and -sensitive S. coagulans (MRSC: 14.3%, 6/42; and MSSC: 2.4%, 1/42) and methicillin-resistant coagulase-negative staphylococci (MR-CoNS: 7.1%, 3/42). Thirty-nine isolates were included after WGS, where all MRS harboured the mecA gene. Eighteen sequence types (STs) were identified, including three novel MRSP and six novel MSSP STs. MRSP ST496-V-VII (23%; 9/39) and MRSP ST749-IV-(IVg) (12.8%; 5/39) were commonly isolated. Phylogenetic analysis of single nucleotide polymorphisms showed that MRSP, MRSC and MSSC were similar to globally isolated staphylococci from canine skin and ear infections. Using cgMLST MSTs, MRSP isolates were not closely related to global strains. Conclusions: Our findings revealed a genotypically diverse geographical distribution and phylogenetic relatedness of staphylococci cultured from clinical canine skin and ear samples across Queensland. This highlights the importance of ongoing surveillance to aid in evidence-based treatment decisions and antimicrobial stewardship.

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.

Background Coagulase-negative Staphylococcus species are an emerging cause of intramammary infection, posing a significant economic and public health threat. The aim of this study was to assess the occurrence of coagulase-negative Staphylococcus species in bovine milk and dairy farms in Northwestern Ethiopia and to provide information about their antibiotic susceptibility and virulence gene profiles. Methods The cross-sectional study was conducted from February to August 2022. Coagulase-negative Staphylococcus species were isolated from 290 milk samples. Species isolation and identification were performed by plate culturing and biochemical tests and the antimicrobial susceptibility pattern of each isolate was determined by the Kirby-Bauer disc diffusion test. The single-plex PCR was used to detect the presence of virulent genes. The STATA software version 16 was used for data analysis. The prevalence, proportion of antimicrobial resistance and the number of virulent genes detected from coagulase-negative Staphylococcus species were analyzed using descriptive statistics. Results Coagulase-negative Staphylococcus species were isolated in 28.6%, (95% CI: 23.5–34.2) of the samples. Of these, the S. epidermidis , S. sciuri , S. warneri , S. haemolyticus , S. simulans , S. chromogens , S. cohnii , and S. captis species were isolated at the rates of 11, 5.2, 3.4, 3.1, 3.1, 1, 1, and 0.7% respectively. All the isolates showed a high percentage (100%) of resistance to Amoxicillin, Ampicillin, and Cefotetan and 37.5% of resistance to Oxacillin. The majority (54.2%) of coagulase-negative isolates also showed multidrug resistance. Coagulase-negative S taphylococcus species carried the icaD , pvl , mecA , hlb , sec , and hla virulent genes at the rates of 26.5%, 22.1%, 21.7%, 9.6%, 9.6% and 8.4% respectively. Conclusion The present study revealed that the majority of the isolates (54.2%) were found multidrug-resistant and carriage of one or more virulent and enterotoxin genes responsible for intramammary and food poisoning infections. Thus, urgent disease control and prevention measures are warranted to reduce the deleterious impact of coagulase-negative species. To the best of our knowledge, this is the first study in Ethiopia to detect coagulase-negative Staphylococcus species with their associated virulent and food poisoning genes from bovine milk.

Background Mastitis is one of the primary causes of economic and production losses in the dairy cattle industry. Bacterial infections are the most significant contributors to bovine mastitis, with Staphylococcus species among the most prevalent and challenging pathogens. This issue is especially severe in low- and middle-income countries, including Ethiopia, where a comprehensive understanding of Staphylococcus species in clinical and subclinical mastitis remains poorly understood. This is particularly true in the regions surrounding Bahir Dar, where comprehensive data on the genetic determinants of virulence and resistance in Staphylococcus species causing bovine mastitis are notably lacking. The lack of such molecular insights hampers the development of targeted therapeutic and preventive strategies for managing mastitis in the region. Therefore, the present study aimed to investigate the virulence gene profiles and antimicrobial resistance (AMR) patterns of Staphylococcus species isolated from mastitic dairy cows in and around Bahir Dar, Ethiopia. Methodology A cross-sectional study was conducted from March 2023 to December 2023 to investigate the molecular characteristics of Staphylococcus species and their antimicrobial resistance profiles in dairy cows with mastitis. A total of 150 lactating cows from 21 farms were included in the study, with 600 milk samples collected from the four-quarters of each cow. The samples were screened via the California mastitis test and physical examination. Staphylococcus species isolates were identified and single-plex PCR was used to detect virulence genes. The antimicrobial resistance profile of the isolates was determined via the Kary–Bauer disk diffusion method. Results The overall quarter-level mastitis incidence was 19.83% (119/600). Among 119 mastitis-positive samples, 80 samples were bacteriologically confirmed to harbor  Staphylococcus species with eight different Staphylococcus species, of which  Staphylococcus chromogenes  was the most prevalent isolate (19%), followed by  S. aureus, S. hyicus  and  S . epidermidis  (15%) , S. hemolyticus  (11%) ,   S. simulans  and  S. xylosus  (10%), and  S. intermedius  (5%). Seven distinct virulence genes were identified with varying frequencies :  Coa (35%), seb (33.33%), mecA (31.67%), icaD (31.67%), Hla (20%), Hlb (10%), and sea (8.3%). The icaD and seb genes were observed in all 8 species with respective percentages ( S. hemolyticus (62.5, 37.5), S. aureus ( 44.44, 55.55),  S. hyicus (44.44, 44.44), S. epidermidis 2 (22.22, 44.44), chromogenes (9.1, 9.1), S. intermidius (33.33, 33.33), S. simulance (16.67, 16.67) and S. xylosus (16.67, 16.67). Both the Hla and Hlb genes were detected in the same three distinct species, with percentages of S. aureus (44.44; 22.22%), S. hemolyticus (42.5; 25%) and S. hyicus (55.55; 22.22). S. aureus exhibited the highest proportion of mecA-positive isolates, with 6 out of 9 isolates (66.67%) carrying the gene. All the isolated Staphylococcus species were 100% resistant to penicillin, and except for S. chromogenes and S. xylosus,  the remaining 6 species of Staphylococcus also exhibited 100% resistance to tetracycline. Among all MDR isolates, 6/9 (66.7%)  S. aureus,  (5/8; 62.5%)  S. hemolyticus,  and (6/9; 66.7%)  S. hyicus  were resistant to up to seven classes of antibiotics. A lower frequency of MDR isolates was detected among  S. simulans and S. xylosus (both at 2/6; 33.33%), resistant to up to five antibiotics. Conclusions Among the identified Staphylococcus species, S. chromogenes emerged as the dominant isolate. All eight isolated species harbored two or more virulence genes, with nearly one-third of the isolates carrying the mecA gene, underscoring their pathogenic potential in causing bovine mastitis. Furthermore, all the Staphylococcus isolates in this study were resistant to penicillin and were multidrug resistant.

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.

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.

Introduction Chronic rhinosinusitis (CRS) pathophysiology and its link to microbiome is an area of ongoing investigation. Certain pathogens, in particular Staphylococcus aureus described to contribute to recalcitrant CRS. In addition, different species of coagulase negative staphylococci (CoNS) are frequently isolated from the sinonasal cavity of CRS patients. However, the influence of Staphylococcal species coexisting in the same niche on the inflammatory process remains unclear. The aim of this study was to explore the impact of exoproteins from various Staphylococcus species isolated from the same patients on the mucosal barrier. Methods Staphylococcal species isolated from CRS and control patients were cultured from sinus swabs in planktonic and biofilm forms, and their exoproteins extracted. Primary human nasal epithelial cells (HNECs) from CRS patients were cultured at an air‐liquid interface (ALI) and exposed to 20 μg/mL exoproteins or control. Barrier disruption and cytotoxicity were assessed by measuring the transepithelial electrical resistance (TEER), passage of fluorescein labeled dextrans and lactate dehydrogenase (LDH) levels. IL‐ 6 concentration was measured employing ELISA. Patient's matched sinonasal tissue samples were analyzed with flow cytometry to detect and quantify immune cells. Results Forty‐four Staphylococcal species were isolated from 22 CRS and control patients including: 22 S. aureus, 12 S. epidermidis, and 10 S. lugdunensis. 15 out of 22 S. aureus exoproteins significantly enhanced cytotoxicity, reduced TEER values and increased paracellular permeability compared to control (p < 0.05). By contrast, S. epidermidis and S. lugdunensis exoproteins caused either mild or negligible effects on the TEER values, cell viability, and paracellular permeability. However, S. lugdunensis exoproteins induced significantly higher IL‐6 compared to control. Correlation analysis indicated S. aureus and S. lugdunensis from the same patient acted in concert to disrupt the nasal epithelial barrier and induce toxicity. Conclusion This study shows the significant and detrimental impact of the presence of S. aureus exoproteins on nasal epithelial cell barrier function. S. aureus and S. lugdunensis isolated from the same patients acted in concert to affect the nasal barrier and inducing toxicity.

BackgroundMethicillin-resistant Staphylococcus species (MRSS) are a global public health threat, causing substantial morbidity, mortality, and economic burden. Understanding the characteristics of MRSS from various niches can support the control of these bacterial species. Herein, we examined the prevalence, biofilm formation, hemolytic activity, and selected aminoglycoside resistance genes in MRSS isolates from potable water and clinical samples in Dutsin-Ma, northwestern Nigeria.MethodsA total of 200 samples, including 100 water and 100 clinical samples, were collected and analyzed. Staphylococcus species was recovered following standard microbiological procedures. Antibiotic susceptibility testing (AST) and minimum inhibitory concentration (MIC) determination were performed using Kirby-Bauer disk diffusion and microdilution methods, respectively. Methicillin-resistant isolates were defined as those resistant to cefoxitin with elevated oxacillin MICs. Coagulase production, biofilm formation, and hemolytic activity were assessed using slide coagulase test, Congo red agar and blood agar, respectively. Multidrug resistant (MDR) isolates were selected for PCR to detect tuf and selected aminoglycoside resistance genes. Fisher’s exact test was performed to check for a significant difference in their occurrence (p ≤ α 0.05). ResultsThirty (15%) isolates were putatively identified, comprising both coagulase-positive staphylococci (CoPS) and coagulase-negative staphylococci (CoNS): 19 (63.3%) from the clinical samples and 11 (36.7%) from the water sources. Of these, 17 strains (41.2%, 7/17) from wound swabs and 58.8% (10/17) from water samples were MDR and methicillin resistant. Virulence traits were present in isolates from both sources; however, there was no significant difference (p ≤ α 0.05) in their occurrence in CoPS and CoNS isolates from both source. Of the selected MDR strains, 16 /17 (94.1%) revealed at least one virulence trait (coagulase, hemolysis, or biofilm). PCR confirmed that 23.5% (4/17) of the selected MDR isolates exclusively from water samples harbored at least one of ant(4’)-Ia, aph(2’)-Ib, aph(3’)-IIIa, or aac(6’), which encode aminoglycoside resistance.ConclusionThese findings suggest the potential role of potable water as a dissemination route for MDR MRSS in the study locality. Further studies are needed to identify the circulating species and sequence types (STs), and to evaluate the prevalence of other antibiotic resistance genes.

Mastitis occurs when microbes invade the teat through the teat canal. Most microbes can cause opportunistic infections of the udder. However, fatal infections are due to various species of Streptococci, Staphylococci, and coliforms. Notable economic effects of bovine mastitis include reduced milk yield, increased treatment costs, and premature culling of affected animals. This systematic review collates published reports of bacterial pathogens isolated from mastitis-positive bovine milk samples in African dairy systems from 2013 to 2023. The search was conducted using Google Scholar, PubMed, Web of Science, and ScienceDirect, and assessed using a modified ROBIS tool. The search terms were: “bovine mastitis”, “bacterial pathogens”, and “African dairy systems”. Findings indicate that Staphylococcus aureus (80%) and Escherichia coli (63%) were among the most frequently reported pathogens. Other frequently reported bacterial species included Streptococcus spp. (37%) and Streptococcus agalactiae (37%). A greater proportion of the studies were based on Ethiopian dairy farming systems. Overall, the results show that mastitis-causing pathogens are common isolates in milk from smallholder African farming systems. Therefore, milk bacterial isolation and testing should be adopted as a standard practice to inform decision-making on mastitis treatment and control programmes.