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.

OBJECTIVE: Fosfomycin has regained attention for treating infections caused by methicillin-resistant Staphylococcus aureus and multidrug-resistant coagulase-negative staphylococci. In this research, our objective was to investigate the mechanisms underlying fosfomycin resistance in Staphylococcus capitis.
METHODS: The minimum inhibitory concentrations (MICs) of fosfomycin were assessed in 109 clinical S. capitis isolates by the agar dilution method. By cloning the fos-like genes into the shuttle vector, pTSSCm-Pcap, and observing the change in fosfomycin MICs, the gene function was verified. Core genome multilocus sequence typing and comparative genomics analysis were conducted to determine the population characteristics of S. capitis isolates and analyse the genetic environment of the fos-like genes.
RESULTS: We identified a novel fosfomycin resistance gene, fosSC, on the chromosome in 58 out of 109 (53.2%) S. capitis isolates. The deduced products of the fosSC genes shared 67.15-67.88% amino acid sequence identity with FosB. The RN-pT-fosSC transformants carrying fosSC showed a 512-fold increase in the fosfomycin MICs. The fosSC gene was embedded in a conserved genetic context, but IS431mec was located to the left of the fosSC gene in cluster L due to the insertion of staphylococcal cassette chromosome mec.
CONCLUSIONS: The chromosomal fosSC genes in some lineages of S. capitis explained their high-level fosfomycin resistance. Ongoing surveillance is crucial for monitoring the potential threat of horizontal transfer, which could be facilitated by the presence of mobile genetic elements surrounding the fosSC gene.

The mechanism of enhanced tigecycline MIC in Staphylococcus cohnii after in vitro tigecycline exposure was investigated. S. cohnii 11-B-312 was exposed to incremental concentrations of tigecycline (2-32 mg/L) and the mutants growing at 8, 16 and 32 mg/L were determined by AST and WGS. Copy number and relative transcription level of the tet(L) gene were determined by quantitative PCR. The fitness cost was evaluated by growth kinetics and competition assays. The results revealed that enhanced tigecycline MIC was identified in S. cohnii mutants. Copy number and relative transcription level of tet(L) in the mutants increased 8-, 20-, and 23-fold and 20-, 34-, and 39-fold in the presence of 8, 16, and 32 mg/L tigecycline, respectively. The read-mapping depth ratio analysis indicated that a multidrug resistance region carrying the tet(L) variant has a gradually increased copy number, correlating with the tigecycline selection pressure. S. cohnii strain 11-B-312_32 had a fitness cost, and enhanced tigecycline MIC can revert to the initial level in the absence of tigecycline. In summary, enhanced tigecycline MIC develops with extensive amplification of an IS257-flanked tet(L)-carrying segment in S. cohnii. IS257 seems to play a vital role in the gain and loss of the amplification product.

Millions of public shared bicycles (PSBs) have been launched in China, and PSBs are a potential reservoir of antimicrobial-resistant staphylococci. However, no national data to elucidate the dissemination, antimicrobial resistance and genotypes of staphylococci has been recovered from public shared bicycles located in different cities in China. Antimicrobial susceptibility, SCCmec types and sequence types of staphylococci were determined. A total of 146 staphylococci were recovered in this study, and 87% staphylococcal isolates were resistant to at least one antibiotic. In total, 29 (20%) staphylococcal isolates harbored mecA gene, and SCCmec types were determined as follows: SCCmec type II (n = 1), IV(n = 3), V (n = 4), VI (n = 1), VIII (n = 2), A/1 (n = 6), A/5 (n = 2), C/1 (n = 2), C/2 (n = 1), C/3 (n = 1), (n = 5) and Pseudo (ψ)-SCCmec (n = 1). Sequence types of 16 Staphylococcus epidermidis were determined, including ST10, ST17, ST59, ST60, ST65, ST130, ST184, ST262, ST283, ST337, ST360, ST454, ST567, ST820, ST878 and ST934. PSBs are a reservoir of diverse antimicrobial-resistant staphylococci, and staphylococcal species differences were observed in isolates that were recovered from public shared bicycles in the south and north of China. PSBs are a source of antimicrobial resistance and genetic diverse staphylococci.

Oroxylum indicum is one of the valuable Dai pharmaceuticals; the dry seeds and bark of O. indicum were used to treat acute cough, sore throat and so on. Of the seven compounds from O. indicum were determined and obtained using the bioassay-guided method. Among them, compound 7 was obtained from the plant for the first time. Eight bacterial strains and one yeast fungi were exposed to the compounds. Minimum inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) or minimum fungicidal concentrations were determined according to the standard broth microdilution method. Baicalein (2) exhibited relative strong antibacterial activities with MIC of 8 μg ml-1 and MBC of 16 μg ml-1 against three MRSA strains of Staphylococcus aureus of SCCmec III type, whereas flavonoids 3, 5 and 7 showed some degree of activities against methicillin-susceptible S. aureus (MSSA, ATCC 25923). The findings may offer new evidence that why O. indicum was used widely in Dai peoples\' life.

Staphylococci belong to conditionally pathogenic bacteria, and the pathogenicity of Staphylococcus aureus is the strongest among them. Enterotoxin produced by it can contaminate food and cause food poisoning. Bacteriocin is a kind of polypeptide with antibacterial activity synthesized by some bacteria during metabolism. In this study, we report on purification, characterization, and mode of action of the bacteriocin named Paracin 54, produced by Lactobacillus paracasei ZFM54. Paracin 54 was purified by precipitation with 80% ammonium sulfate, strong cation-exchange chromatography, G-25 gel column, and reversed-phase high-performance liquid chromatography (HPLC). The molecular weight of Paracin 54 (5718.1843 Da) was determined by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Paracin 54 showed broad-spectrum inhibitory activity. It had a strong inhibitory effect on Staphylococci with minimum inhibitory concentration values of 3.00-4.50 μg/mL. Paracin 54 was heat-stable and active only in acidic pH range (2-6). After treatment with proteases, the activity was lost. The results of mode of action showed Paracin 54 damaged the cell membrane and cell wall of Staphylococcus aureus, and then the cytoplasm leaked out, leading to death of the bacteria. These properties make Paracin 54 a promising candidate to prevent the growth of spoilage bacteria and control food poisoning caused by Staphylococci. KEY POINTS: • Paracin 54 was purified from Lactobacillus paracasei ZFM54 with good biochemical characteristics. • Paracin 54 had a strong effect against Staphylococci, making it a promising preservative to prevent the growth of Staphylococci in food. • The mode of action of Paracin 54 on Staphylococcus aureus was revealed.

UNASSIGNED: To report antibiotic resistance rates and trends of common ocular isolates collected over a 15-year period.
UNASSIGNED: We collected 3533 isolates from July 1, 2005 to July 31, 2020. Antibiotic sensitivity was determined according to the guidelines of the Clinical and Laboratory Standards Institute. Chi-squared (χ 2) test was used to analyze changes in antibiotic susceptibility over 15 years.
UNASSIGNED: Among the 3533 isolates, the predominant pathogens were the staphylococcal species. Methicillin resistance was observed in 381 Staphylococcus aureus (S. aureus) isolates (46.4%) and 1888 coagulase-negative staphylococci (CoNS) isolates (61.1%), and methicillin-resistant (MR) isolates had a high probability of concurrent resistance to fluoroquinolones and aminoglycosides. The mean percentage of resistance in staphylococcal isolates did not reach statistical significance across patient age groups (P = 0.87). Methicillin resistance did not increase in the CoNS (P = 0.546) isolates, and resistance to methicillin slightly decreased among S. aureus (P = 0.04) isolates over 15 years. Additional exploratory analysis revealed a small decrease in resistance to tobramycin (P = 0.01) and chloramphenicol (P < 0.001) among the CoNS isolates. All staphylococcal isolates were susceptible to vancomycin.
UNASSIGNED: Staphylococci were the most common microorganisms responsible for causing ocular infections. Antibiotic resistance was high among staphylococci, with nearly half of these isolates were resistant to methicillin and these had a high probability of concurrent resistance among MR staphylococci to other antibiotics. Overall, ocular resistance did not significantly change during the 15-year study period. We conclude that continued surveillance of antibiotic resistance provides critical data to guide antibiotic selection.

BACKGROUND: Coagulase-negative Staphylococci (CoNS) are opportunistic pathogens. Methicillin-resistant CoNS (MRCoNS) remain a major cause of nosocomial infections, but limited information is available in communities. We, therefore, aimed to investigate the epidemiology of CoNS nasal carriage, especially MRCoNS in community-based drug users.
METHODS: Drug users were included in the cross-sectional study from three communities in Guangzhou, China. A face-to-face questionnaire was used to collect individual information and nasal swabs were collected to identify CoNS and MRCoNS isolates. Phenotypic and genotypic characterization of MRCoNS isolates were detected by using the disk diffusion method and polymerase chain reaction assays. Factors impacting MRCoNS carriage were assessed and estimated odds ratios (ORs) and 95% confidence intervals (CIs) by using logistic regression models.
RESULTS: Overall, 353 drug users were eligible and included in the study. The prevalence of CoNS and MRCoNS were 42.78% and 29.18%, respectively. Having a history of being in prison (aOR = 2.16, 95% CI: 1.10-4.22) and a history of heroin snorting in the past 6 months (aOR = 1.87, 95% CI: 1.14-3.05) were risk factors for MRCoNS nasal carriage in drug users. The proportions of multidrug resistance for CoNS and MRCoNS isolates were respectively 54.38% and 66.07%. The predominant multidrug resistance pattern for CoNS and MRCoNS isolates was simultaneously non-susceptible to penicillin, cefoxitin and trimethoprim-sulfamethoxazole. MRCoNS isolates that were positive for erythromycin- (χ2 = 15.49, P < 0.001), tetracycline- (χ2 = 44.88, P < 0.001), penicillin- (χ2 = 3.86, P = 0.049), clindamycin- (χ2 = 4.18, P = 0.028), and gentamicin- (χ2 = 20.66, P < 0.001) resistance genes had significantly higher rates of resistance to corresponding antibiotics.
CONCLUSIONS: The prevalence of MRCoNS nasal carriage was high in community-based drug users. Drug users with risk factors should be paid greater attention to. The use of antibiotics in drug users needs further investigation and control.

We report a SCCmec II, ST39 methicillin-resistant Staphylococcus aureus isolate from pigs that harboured toxic-shock syndrome toxin gene (tsst-1). The gene was located in a rare pathogenicity island SaPI68111, which also carried enterotoxin genes that can cause fatal infections. Pigs may potentially serve as a reservoir for MRSA dissemination.

Laccases are multicopper oxidases with important industrial value. In the study, a novel laccase gene (mco) in a Staphylococcus haemolyticus isolate is identified and heterologously expressed in Escherichia coli. Mco shares less than 40% of amino acid sequence identities with the other characterized laccases, exhibiting the maximal activity at pH 4.0 and 60°C with 2,2\'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) as a substrate. Additionally, the Mco is tolerant to a wide range of pH, heavy metal ions and many organic solvents, and it has a high decolorization capability toward textile dyes in the absence of redox mediators. The characteristics of the Mco make this laccase potentially useful for industrial applications such as textile finishing. Based on BLASTN results, mco is found to be widely distributed in both the bacterial genome and bacterial plasmids. Its potential role in oxidative defense ability of staphylococci may contribute to the bacterial colonization and survival.