Senolytic Therapy: A Potential Approach for the Elimination of Oncogene-Induced Senescent HPV-Positive Cells

Senescence represents a unique cellular stress response characterized by a stable growth arrest, macromolecular alterations, and wide spectrum changes in gene expression. Classically, senescence is the end-product of progressive telomeric attrition resulting from the repetitive division of somatic cells. In addition, senescent cells accumulate in premalignant lesions, in part, as a product of oncogene hyperactivation, reflecting one element of the tumor suppressive function of senescence. Oncogenic processes that induce senescence include overexpression/hyperactivation of H-Ras, B-Raf, and cyclin E as well as inactivation of PTEN. Oncogenic viruses, such as Human Papilloma Virus (HPV), have also been shown to induce senescence. High-risk strains of HPV drive the immortalization, and hence transformation, of cervical epithelial cells via several mechanisms, but primarily via deregulation of the cell cycle, and possibly, by facilitating escape from senescence. Despite the wide and successful utilization of HPV vaccines in reducing the incidence of cervical cancer, this measure is not effective in preventing cancer development in individuals already positive for HPV. Accordingly, in this commentary, we focus on the potential contribution of oncogene and HPV-induced senescence (OIS) in cervical cancer. We further consider the potential utility of senolytic agents for the elimination of HPV-harboring senescent cells as a strategy for reducing HPV-driven transformation and the risk of cervical cancer development.

Cefixime and cefixime-clavulanate for screening and confirmation of extended-spectrum beta-lactamases in Escherichia coli

Introduction

Detection of Extended-Spectrum Beta-Lactamases (ESBLs) depends on screening for resistance to certain cephalosporins, confirmation with selective ESBL inhibitors, and ESBL genes detection. New tests are required for accurate ESBL detection.

Aims

To test the ability of cefixime (CFM) and cefixime-amoxicillin/clavulanate (CFM-AMC) as a screening and confirmatory test for ESBL identification.

Methods

246 clinical isolates of Escherichia coli were tested by an ESBL screening test, a double-disk synergy test (DDST), a disk replacement test, the Vitek 2 ESBL test, and an ESBL genes test by PCR. CFM ESBL Screening was performed by disk diffusion, while CFM-AMC confirmation was performed by DDST and a disk replacement test.

Results

246 E. coli clinical isolates from two referral hospitals were collected over 2 years. The mean age ± standard deviation of patients was 43.8 ± 27.7 years and 76.8% were females. Resistance rates to penicillins, first, second, and third generation cephalosporins, and monobactams were very high at 97%, 84%, 100% and 97%, respectively. ESBL screening was positive in 81.3% of isolates, DDST was positive in 74.8%, disk replacement was positive in 79%, Vitek 2 ESBL test was positive in 67.3%, and ESBL genes were detected in 85.8% of isolates (CTX-M 75%, TEM 42.5%, SHV 4.6%). Compared to genotyping, screening with CFM achieved 87.7% sensitivity and 64.7% specificity. CFM-AMC DDST achieved 75.8% sensitivity and 75.4% specificity, and CFM-AMC disk replacement had 73% sensitivity and 70% specificity.

Conclusions

High prevalence of ESBLs was noted among E. coli isolates, dominated by CTX-M genotype. ESBL screening and confirmation using CFM and CFM-AMC is a new and accurate method for ESBLs detection.

Multidrug-Resistant Acinetobacter baumannii in Jordan

Background: Acinetobacter baumannii is a common cause of multi-drug (MDR)-resistant infections worldwide. The epidemiological and molecular characteristics of MDR-A. baumannii in Jordan is not known. Methods: A. baumannii isolates were collected from 2010 to 2020 from three tertiary hospitals in Jordan. Demographic and clinical data, isolates information, antibiotic susceptibility patterns, phenotypic, and molecular characterization of carbapenem resistance genes were performed. Results: A total of 622 A. baumannii isolates were collected during the study period. Most isolates were from males, aged 18−60 years, Jordanian, from infected wounds, and were patients in surgery or critical care units. Among patients from whom A. baumannii was isolated, associated risk factors for MDR were adults over 60, males, critically ill patients and infected wounds (OR 4.14, 2.45, 10, 7, respectively, p < 0.0001). Incidence rates from 2010 to 2015 showed a slight increase in MDR (3.75/1000 to 4.46/1000). Resistance patterns indicated high resistance for most cephalosporins, carbapenems, and fluoroquinolones, moderate resistance for trimethoprim/sulfamethoxazole and ampicillin/sulbactam, low resistance for aminoglycosides and tetracyclines, while colistin and tigecycline, have the lowest resistance rates. 76.8% of A. baumannii isolates were MDR and 99.2% were carbapenem-resistant. All isolates were positive for the OXA-51 gene (100%), 98.5% were positive for the OXA-23 gene, 26.6% for the VIM gene, while KPC and IMP genes were almost not detected (0% and 0.8% respectively). Conclusions: This is the first large, multicentric, prolonged study that provides insights into A. baumannii infections in Jordan. Attention to patients at higher risk is important for early identification. Colistin and tigecycline were the most effective antimicrobials.

Status of Biofilm-Forming Genes among Jordanian Nasal Carriers of Methicillin-Sensitive and Methicillin-Resistant Staphylococcus aureus

Introduction:

Biofilm formation in Staphylococcusaureus is a major virulence factor. Both MSSA and MRSA are common causes of community- and hospital-acquired infections and are associated with biofilm formation. The status of biofilm-forming genes has not been explored in Jordanian nasal carriers of S. aureus. This study investigates antibiotic resistance patterns and the prevalence of biofilm-forming genes between MSSA and MRSA in two distinct populations in Jordan.

Methods:

A total of 35 MSSA and 22 MRSA isolates were recovered from hospitalized patients and medical students at Prince Hamzah Hospital, Jordan. Antibiotic susceptibility was tested using disk diffusion method and Vitek 2 system. The phenotypic biofilm formation was tested using CRA and microtiter plate assays. The prevalence of the biofilm-forming genes was determined using multiplex PCR.

Results:

Among 57 S.aureus isolates, 22 (38.6%) isolates were MRSA and were highly resistant against benzylpenicillin, oxacillin, and imipenem. The frequencies of the icaADBC were 77.1%, 97.1%, 94.3%, and 97.1% respectively in MSSA compared to 86.4%, 100%, 100%, and 100% in MRSA isolates. On the other hand, the frequency of the fnbA, fnbB, clfA, fib, clfB, ebps, eno, and cna genes was 81.8%, 90.9%, 95.5%, 90.9%, 86.4%, 100%, 100%, and 40.9%, respectively in the MRSA isolates.

Conclusion:

In both groups, MRSA isolates, in comparison to MSSA, were significantly more resistant to cefoxitin, oxacillin, imipenem, tetracycline, clindamycin, and trimethoprim-sulfamethoxazole. Unexpectedly, biofilm formation and gene prevalence between MRSA and MSSA isolates showed no significant difference, suggesting other potential virulence mechanisms.

Prevalence of Human Papillomavirus Associated with Head and Neck Squamous Cell Carcinoma in Jordanian Patients

Background:

In addition to smoking and alcohol consumption, human papillomavirus (HPV) is a leading etiology for Head and Neck Squamous Cell Carcinoma (HNSCC). However, this causal association is still understudied in Middle Eastern populations.

Objective:

The aim of this study was to determine the prevalence of HPV-associated infection in the Jordanian HNSCC patients and the associated HPV genotypes.

Methods:

Formalin-Fixed Paraffin-Embedded (FFPE) squamous cell carcinoma samples of the head and neck were collected from two referral centers in Amman, Jordan to determine the existence of HPV DNA. After DNA extraction HPV infection and genotyping were identified using real-time PCR.

Results:

HPV DNA was detected in 19 out of 61 (31.1%) HNSCC samples. Despite screening for 28 different genotypes, HPV 16 was the only genotype identified in all examined samples. Most HPV-positive samples were obtained from the oropharynx (41.7%), oral cavity (37%), and larynx (18.2%). No significant association between HPV 16 genotype and age, sex, tobacco use, anatomical location, or tumor grade was noticed.

Conclusion:

This study reported a high association between HPV 16 genotype and HNSCC in Jordanian patients. These data should facilitate the implementation of appropriate HPV awareness campaigns, and activate selective prophylactic measures against HPV infection.

Methicillin and vancomycin resistance in coagulase-negative Staphylococci isolated from the nostrils of hospitalized patients

INTRODUCTION

Nasal colonization by coagulase-negative Staphylococci (CoNS) play an important role in nosocomial infections. This study aims to determine antibiotics susceptibility pattern and molecular screening of methicillin- and vancomycin-resistant nasal CoNS among hospitalized patients.

METHODOLOGY

Nasal swabs were collected from 202 inpatients at Prince Hamzah Hospital, Jordan. Swabs were processed according to standard microbiological procedures to isolate Staphylococci. Antibiotic susceptibility testing was performed using disk diffusion, E-test, microdilution, and Vitek 2. Molecular analysis was performed using PCR for the detection of mecA, vanA, and vanB genes.

RESULTS

Nasal Staphylococci was isolated in 64/202 (31.7%) samples. Thirty isolates (14.8%) were CoNS, including S. haemolyticus (n = 17, 8.4%), S. sciuri (n = 6, 3%), S. epidermidis (n = 2, 1%), S. warneri (n = 2, 1%), S. hominis (n = 2, 1%), and S. lentus (n = 1, 0.5%). Twenty-two (10.9%) isolates were MR-CoNS harboring mecA gene. CoNS and MR-CoNS isolates were highly resistant to benzylpenicillin, erythromycin, fosfomycin, and imipenem. All isolates were sensitive to vancomycin by E-test and microdilution test and were negative for vanA and vanB genes. Nasal CoNS colonization was associated with an increased number of family members living with the participant (P = 0.04) and with admission to the orthopedic department (P = 0.03), while MR-CoNS colonization was associated with smoking (P = 0.03).

CONCLUSIONS

Nasal colonization by unusual CoNS species and mecA-positive MR-CoNS are common among hospitalized patients. Absence of vanA and vanB genes suggests little contribution of nasal CoNS to vancomycin resistance transmission.

Phenotypic and Molecular Screening of Nasal S. aureus from Adult Hospitalized Patients for Methicillin- and Vancomycin-resistance

INTRODUCTION

Nasal carriers of Staphylococcus aureus are common and play an important role in the transmission of infections. The aim of this study is a phenotypic and molecular investigation of nasal methicillin- and vancomycin-resistant S. aureus in hospitalized patients.

METHODS

202 nasal swabs were collected from patients at Prince Hamzah Hospital, Jordan, through 2016-2017. Swabs were processed according to standard microbiological procedures to isolate Staphylococci. Antibiotic susceptibility testing was performed using disk diffusion, E-test, microdilution and Vitek 2. Methicillin resistance was confirmed by testing for the mecA gene, while vancomycin resistance was screened by testing for the vanA and vanB genes.

RESULTS

The mean age of participants was 50.17±18.18 years and 59.4% were females. Nasal Staphylococci was isolated in 64/202 (31.7%), S. aureus was isolated from 33 samples (16.3%), MRSA was isolated from 13 samples (6.4%) and constitutive Macrolide-lincosamidestreptogramin B (MLSB) was isolated from 12 samples (5.9%). All MRSA isolates harbored the mecA gene. All isolates were sensitive to vancomycin using E-test and the microdilution test and were negative for the vanA and vanB genes. The highest resistance rate was observed for benzylpenicillin (>90%), while the lowest resistance rate was for tobramycin (<5%) among all isolates. Nasal Staphylococci, S. aureus and MRSA colonization significantly correlate with increased number of family members and previous hospitalization (P<0.05), while nasal S. aureus significantly correlates with a history of skin infection (P=0.003).

CONCLUSION

Nasal colonization by mecA-mediated MRSA is common among hospitalized patients, while vanA- and vanB-mediated vancomycin resistance was not detected in any nasal isolates.

Effective Oral Combination Treatment for Extended-Spectrum Beta-Lactamase-Producing Escherichia coli

Background: Extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) is increasing worldwide. The drugs of choice for treatment of ESBLs are parenteral carbapenems. The aim of this study was to evaluate the in vitro and in vivo efficacy of a new combination of oral cephalosporins and amoxicillin/clavulanate in treatment of ESBL-EC. Methods: A total of 150 ESBL-EC samples were collected over 1 year from two referral centers. Synergistic studies of cephalosporins and amoxicillin/clavulanate were performed in vitro using disk approximation and disk replacement methods. Combination treatment was assessed in vivo on 20 ESBL-EC urinary tract infection (UTI) patients. Results: ESBL-EC isolates were confirmed in 150 patients with a mean age of 46.67 years, 75.2% of them being women. Antibiotic susceptibility testing of isolates indicated high resistance rate to oral antibiotics. The frequency of positive synergy and mean distance of synergy between cephalosporins and amoxicillin/clavulanate was significantly higher with cefotaxime and cefixime compared with cefpodoxime, cefdinir, and ceftazidime using disk approximation and disk replacement methods (p < 0.05). Addition of amoxicillin/clavulanate enhanced the susceptibility rate with cefixime from 8.6% to 86.3%, significantly higher than with other cephalosporins (p < 0.0005). Cefixime and amoxicillin/clavulanate synergy was not affected by age, gender, hospital, department, sample type, or bacterial load. Eighteen of 20 ESBL-EC-positive UTI patients had a positive in vitro synergy test and complete clinical and microbiological resolution after completion of cefixime and amoxicillin/clavulanate oral treatment course. Conclusions: Cefixime and amoxicillin/clavulanate combination therapy could be an effective oral outpatient treatment option for ESBL-EC. In vitro synergistic testing is simple and predictive of successful treatment.

Isolation of Fully Vancomycin-Resistant Streptococcus thoraltensis from the Nasal Cavity of a Healthy Young Adult

BACKGROUND

Streptococcus thoraltensis was first isolated from pigs and rabbits. Later, isolation from human oral and nasal cavities and from throat and oropharynx was documented. S. thoraltensis was isolated from patients with periodontitis, tonsillopharyngitis, and chorioamnionitis suggesting a possible pathological role in human infections. All S. thoraltensis isolates of animal and human origins were sensitive to vancomycin.

METHODS

Standard microbiological identification methods, biochemical analysis, and antibiotic susceptibility testing using disk diffusion and E methods were used. Automatic species identification and antibiotic susceptibility testing were carried out using the Vitek 2 compact system. Molecular analysis of vancomycin resistance gene was carried out using a PCR with specific primers for vanA.

RESULTS

We report a healthy young female adult, aged 19 years, with history of exposure to pet rabbit who had nasal colonization with S. thoraltensis. Identification of S. thoraltensis was based on traditional microbiological methods (culture, Gram stain, and biochemical tests), and the Vitek 2 compact system with 97% confidence rate. Antibiotic susceptibility testing of the isolate indicated resistance to most antibiotics, including penicillins, cephalosporins, methicillin, and glycopeptides. The minimal inhibitory concentration for vancomycin and teicoplanin was exceptionally high (>256 μg/mL). Molecular analysis indicated the absence of vanA gene in S. thoraltensis.

CONCLUSION

We report for the first time the isolation of a fully vancomycin-resistant S. thoraltensis independent of vanA from a healthy human anterior nasal cavity. The pathological role of this newly identified organism with an exceptionally rare resistance pattern in human infections is yet to be identified.

Nasal colonization by methicillin-sensitive and methicillin-resistant Staphylococcus aureus among medical students

INTRODUCTION

Nasal carriers of methicillin-resistant Staphylococcus aureus (MRSA) are common and play an important role in nosocomial infections. The prevalence rate and characterization of nasal carriers of MRSA among medical students in Jordan has not been investigated before.

METHODOLOGY

The resistance of S. aureus to several antibiotics was tested using disc diffusion method, automatic Vitek 2, and penicillin binding protein (PBP) 2 slide test. Bacterial species and resistance genes were confirmed using molecular analysis of three relevant genes by real-time PCR. Two hundred ninety nasal swabs were collected from medical students at Hashemite University from June 2015 to August 2016. All participants signed a voluntary consent form and filled a predesigned questionnaire.

RESULTS

The mean age of participants was 19.7 ± 2 years and 61.7% of them were males. 63 out of the 290 (21.7%) samples were identified to have S. aureus, 56 (19.3%) were methicillin-sensitive S. aureus (MSSA) and 7 (2.4%) were MRSA. S. aureus nasal colonization significantly associates with male gender (OR = 1.7, CI = 0.94-3.18, P = 0.049) and chronic illnesses (OR = 4.0, CI = 1.52-10.65, P = 0.006). Consistency between disc diffusion, Vitek 2, and PBP 2 methods for MRSA screening were satisfactory compared to molecular analysis. All MRSA samples were positive for SCCmec:orfx junction gene (MRSA-specific), nuc gene (S. aureus- specific), mecA gene (PBP-mediated resistant), and PBP2 production. All MRSA isolates were multi-drug resistant and were sensitive to Linezolid, Vancomycin, and Tigecycline.

CONCLUSIONS

This study confirms that nasal colonization by MRSA among medical students necessitates further attention to prevent nosocomial infections.