The antibiotic resistance (ABR) crisis is an urgent global health priority. Staphylococci are among the problematic bacteria contributing to this emergency owing to their recalcitrance to many clinically important antibiotics. Staphylococcal pathogenesis is further complicated by the presence of small colony variants (SCVs), a bacterial subpopulation displaying atypical characteristics including retarded growth, prolific biofilm formation, heightened antibiotic tolerance, and enhanced intracellular persistence. These capabilities severely impede current chemotherapeutics, resulting in chronic infections, poor patient outcomes, and significant economic burden. Tackling ABR requires alternative measures beyond the conventional options that have dominated treatment regimens over the past 8 decades. Non-antibiotic therapies are gaining interest in this arena, including the use of honey, which despite having ancient therapeutic roots has now been reimagined as an alternative treatment beyond just traditional topical use, to include the treatment of an array of difficult-to-treat staphylococcal infections. This literature review focused on Manuka honey (MH) and its efficacy as an anti-staphylococcal treatment. We summarized the studies that have used this product and the technologies employed to study the antibacterial mechanisms that render MH a suitable agent for the management of problematic staphylococcal infections, including those involving staphylococcal SCVs. We also discussed the status of staphylococcal resistance development to MH and other factors that may impact its efficacy as an alternative therapy to help combat ABR.

There is a scarcity of published studies on the occurrence of Staphylococcus spp. Among dogs in South Africa. The objective of the study was to characterise the Staphylococcus spp. Isolated from dog samples submitted to a veterinary diagnostic laboratory in South Africa in terms of time, place, and person. This study utilised a dataset of 1627 positive Staphylococcus isolates obtained from a veterinary diagnostic laboratory in South Africa from 2012 to 2017. Out of the 1627 confirmed isolates, 10 different species of Staphylococcus were identified. Among these, 92.0% were classified as coagulase-positive staphylococci (CoPS), 6.0% were coagulase-negative staphylococci (CoNS), and 3.0% were coagulase-variable. Male dogs contributed just over half (53.2%) of the Staphylococcus isolates, while female dogs contributed the remaining 46.8%. The largest proportion of isolates (23.2%) were obtained from dogs aged ≥ 9 years, with the highest number of isolates originating from KwaZulu-Natal Province (45.0%) and the least from Northern Cape Province (0.1%). Out of the total samples included in the records, the majority (46.0%) were skin specimens. The number of Staphylococcus isolates recorded showed limited variation between the seasons (24.3% in autumn, 26.3% in winter, 26.0% in spring, and 24.0% in summer). This study highlighted the diversity of Staphylococcus spp. isolated from dogs, and the burden of staphylococcal carriage among dogs in South Africa. Further research is required to examine the factors that contribute to the observed discrepancies in the proportions of Staphylococcus spp. between the provinces.

Staphylococcus epidermidis, a common commensal bacterium found on human skin, can cause infections in clinical settings, and the presence of antibiotic resistance genes (ARGs) impedes the treatment of S. epidermidis infections. However, studies characterizing the ARGs in S. epidermidis with regard to genomic and ecological diversities are limited. Thus, we performed a comprehensive and comparative analysis of 405 high-quality S. epidermidis genomes, including those of 35 environmental isolates from the Han River, to investigate the genomic diversity of antibiotic resistance in this pathogen. Comparative genomic analysis revealed the prevalence of ARGs in S. epidermidis genomes associated with multi-locus sequence types. The genes encoding dihydrofolate reductase (dfrC) and multidrug efflux pump (norA) were genome-wide core ARGs. β-Lactam class ARGs were also highly prevalent in the S. epidermidis genomes, which was consistent with the resistance phenotype observed in river isolates. Furthermore, we identified chloramphenicol acetyltransferase genes (cat) in the plasmid-like sequences of the six river isolates, which have not been reported previously in S. epidermidis genomes. These genes were identical to those harbored by the Enterococcus faecium plasmids and associated with the insertion sequence 6 family transposases, homologous to those found in Staphylococcus aureus plasmids, suggesting the possibility of horizontal gene transfer between these Gram-positive pathogens. Comparison of the ARG and virulence factor profiles between S. epidermidis and S. aureus genomes revealed that these two species were clearly distinguished, suggesting genomic demarcation despite ecological overlap. Our findings provide a comprehensive understanding of the genomic diversity of antibiotic resistance in S. epidermidis.
OBJECTIVE: A comprehensive understanding of the antibiotic resistance gene (ARG) profiles of the skin commensal bacterium and opportunistic pathogen Staphylococcus epidermidis needs to be documented from a genomic point of view. Our study encompasses a comparative analysis of entire S. epidermidis genomes from various habitats, including those of 35 environmental isolates from the Han River sequenced in this study. Our results shed light on the distribution and diversity of ARGs within different S. epidermidis multi-locus sequence types, providing valuable insights into the ecological and genetic factors associated with antibiotic resistance. A comparison between S. epidermidis and Staphylococcus aureus revealed marked differences in ARG and virulence factor profiles, despite their overlapping ecological niches.

Biofilms are surface-associated microbial communities embedded in a matrix that is almost impenetrable to antibiotics, thus constituting a critical health threat. Biofilm formation on the cornea or ocular devices can lead to serious and difficult-to-treat infections. Nowadays, natural molecules with antimicrobial activity and liposome-based delivery systems are proposed as anti-biofilm candidates. In this study, the anti-biofilm activity of a formulation containing citrus polyphenols encapsulated in liposomes was evaluated against Staphylococcus aureus and Staphylococcus epidermidis, the most common agents in ocular infections. The formulation activity against planktonic staphylococci was tested by broth microdilution and sub-inhibitory concentrations were used to evaluate the effect on biofilm formation using the crystal violet (CV) assay. The eradicating effect of the preparation on mature biofilms was investigated by the CV assay, plate count, and confocal laser scanning microscopy. The product was bactericidal against staphylococci at a dilution of 1:2 or 1:4 and able to reduce biofilm formation even if diluted at 1:64. The formulation also had the ability to reduce the biomass of mature biofilms without affecting the number of cells, suggesting activity on the extracellular matrix. Overall, our results support the application of the used liposome-encapsulated polyphenols as an anti-biofilm strategy to counter biofilm-associated ocular infections.

Of the 27 million surgeries performed in the United States each year, a reported 2.6% result in a surgical site infection (SSI), and Staphylococci species are commonly the culprit. Alternative therapies, such as nitric oxide (NO)-releasing biomaterials, are being developed to address this issue. NO is a potent antimicrobial agent with several modes of action, including oxidative and nitrosative damage, disruption of bacterial membranes, and dispersion of biofilms. For targeted antibacterial effects, NO is delivered by exogenous donor molecules, like S-nitroso-N-acetylpenicillamine (SNAP). Herein, the impregnation of SNAP into poly(lactic-co-glycolic acid) (PLGA) for SSI prevention is reported for the first time. The NO-releasing PLGA copolymer is fabricated and characterized by donor molecule loading, leaching, and the amount remaining after ethylene oxide sterilization. The swelling ratio, water uptake, static water contact angle, and tensile strength are also investigated. Furthermore, its cytocompatibility is tested against 3T3 mouse fibroblast cells, and its antimicrobial efficacy is assessed against multiple Staphylococci strains. Overall, the NO-releasing PLGA copolymer holds promise as a suture material for eradicating surgical site infections caused by Staphylococci strains. SNAP impregnation affords robust antibacterial properties while maintaining the cytocompatibility and mechanical integrity.

UNASSIGNED: Bacterial infections causing digestive problems are among the most serious threats to Egypt\'s duck industry, owing to their effects on feed utilization and body weight gain.
UNASSIGNED: As a result, the goal of this study was to identify bacterial pathogens causing enteritis in ducks as well as testing their antimicrobials resistance capabilities.
UNASSIGNED: Forty-two duck flocks from different localities at four Egyptian Governorates (El-Sharkia, El-Gharbia, El-Dakahlia, and El-Qaliobia) have been subjected to clinical and postmortem examination as well as bacterial isolation and identification. The liver samples have been collected aseptically from freshly euthanized ducks for bacterial isolation followed by identification using conventional biochemical tests, VITEK 2 system, and confirmatory polymerase chain reaction (PCR) for detection of the uid A gene (beta-glucuronidase enzyme) of Escherichia coli. In addition, antimicrobial sensitivity testing for the isolates against different antimicrobials by the VITEK 2 system was used.
UNASSIGNED: Forty-six positive bacterial isolates were identified using conventional methods and the VITEK 2 system including Staphylococcus spp. (52.17%), E. coli (41.30%), and 2.17% for each of Enterococcus casseli lavus, Salmonella enterica subspecies arizonae, and Enterobacter cloacae. PCR was positive for E. coli uid A gene at 556 bp. The antibiogram patterns of isolated pathogens from naturally infected ducks in our work demonstrated 87% multidrug resistance with varying results against different antimicrobial drugs tested. Such findings supported the fact of the upgrading multidrug resistance of Staphylococci and Enterobacteriacae.
UNASSIGNED: The most prevalent bacterial pathogens associated with duck enteritis were Staphylococcus spp. and E. coli with the first report of S. enterica subspecies arizonae causing duck enteritis in Egypt.

Antimicrobial photoinactivation (API) has shown some promise in potentially treating different nosocomial bacterial infections, however, its application on staphylococci, especially other than Staphylococcus aureus or methicillin-resistant S. aureus (MRSA) species is still limited. Although S. aureus is a well-known and important nosocomial pathogen, several other species of the genus, particularly coagulase-negative Staphylococcus (CNS) species such as Staphylococcus epidermidis and Staphylococcus saprophyticus, can also cause healthcare-associated infections and foodborne intoxications. CNS are often involved in resilient biofilm formation on medical devices and can cause infections in patients with compromised immune systems or those undergoing invasive procedures. In this study, the effects of chlorophyllin and riboflavin-mediated API on S. epidermidis and S. saprophyticus planktonic cells and biofilm are demonstrated for the first time. Based on the residual growth determination and metabolic reduction ability changes, higher inactivating efficiency of chlorophyllin-mediated API was determined against the planktonic cells of both tested species of bacteria and against S. saprophyticus biofilm. Some insights on whether aqueous solutions of riboflavin and chlorophyllin, when illuminated with optimal exciting wavelength (440 nm and 402 nm, respectively) generate O2-•, are also provided in this work.

The purpose of this investigation was to evaluate the microbial quality and safety of rabbit meat. A total of 49 rabbit meat samples were taken at the retail level. The mesophiles, staphylococci, Enterobacterales, and Pseudomonas spp. counts were 4.94 ± 1.08, 2.59 ± 0.70, 2.82 ± 0.67, and 3.23 ± 0.76 log CFU/g, respectively. Campylobacter spp. were not detected in any sample. Listeria monocytogenes was isolated from one sample (2.04%) at levels below 1.00 log CFU/g. Multi-resistant S aureus was found in seven samples (14.9%). Methicillin-resistant S. aureus, S. epidermidis, S. haemolyticus, M. caseolyticus, and M. sciuri were found in a sample each (10.20%), and all of them were multi-resistant. Multi-resistant ESBL-producing E. coli were detected in two samples from the same retailer (4.08%). The high resistance found in methicillin-resistant staphylococci and ESBL-producing E. coli is of particular concern, and suggests that special measures should be taken in rabbit meat.

During the current investigation, eight essential oils (EOs) were tested for their antimicrobial activity against six species, belonging to the genus of staphylococcus, multi-resistant to antibiotics (S. epidermidis, S. cohni, S. wareneri, S. scuiri, S. chromogenes, S. pasteuri), three methicillin-resistant Staphylococcus aureus strains (MRSA) and two strains of Escherichia coli, producing extended-spectrum β-lactamase (ESBL) responsible for bovine mastitis. Our results indicated that the antimicrobial activities of eight EOs varied significantly among the types of EOs and bacterial species. Thymus capitatus and Trachyspermum ammi EOs display important antibacterial activity against all tested strains, with the inhibition zone diameters situated between 20 and 45 mm, while EOs of Artemisia absinthium, Eucalyptus globulus, Eucalyptus camaldulensis, Myrtus communis and Mentha pulegium exerted an intermediate activity. For Cymbopogon citratus, this effect depends on bacteria species. In fact, an important effect was observed against S. warneri, S. epidermidis, S. cohenii, S. pasteuri and MRSA (EC 39+) strains. In addition, the important lytic effect was observed against MRSA strains, showing that Gram-positive bacteria were more sensitive to T. capitatus EO than Gram-negative ones. Concerning the characterization of the mode action of T. capitatus, experiments of kill-time, bacteriolytic, loss of salt tolerance and loss of cytoplasmic material showed that the used EO was able to destroy cell walls and membranes followed by the loss of vital intracellular materials. In addition, it inhibits the normal synthesis of DNA, causing the bacterial death of E. coli and MRSA strains. This study shows the potential of using of EOs, particularly T. capitaus, to inhibit the growth of Gram-positive and Gram-negative bacteria multi-resistant to antibiotics causing bovine mastitis.

Many bacteria produce antimicrobial compounds such as lantibiotics to gain advantage in the competitive natural environments of microbiomes. Epilancins constitute an until now underexplored family of lantibiotics with an unknown ecological role and unresolved mode of action. We discovered production of an epilancin in the nasal isolate Staphylococcus epidermidis A37. Using bioinformatic tools, we found that epilancins are frequently encoded within staphylococcal genomes, highlighting their ecological relevance. We demonstrate that production of epilancin A37 contributes to Staphylococcus epidermidis competition specifically against natural corynebacterial competitors. Combining microbiological approaches with quantitative in vivo and in vitro fluorescence microscopy and cryo-electron tomography, we show that A37 enters the corynebacterial cytoplasm through a partially transmembrane-potential-driven uptake without impairing the cell membrane function. Upon intracellular aggregation, A37 induces the formation of intracellular membrane vesicles, which are heavily loaded with the compound and are essential for the antibacterial activity of the epilancin. Our work sheds light on the ecological role of epilancins for staphylococci mediated by a mode of action previously unknown for lantibiotics.