Gamal Fadl Mahmoud Gad

Design, synthesis, antibacterial activity and physicochemical parameters of novel N-4-piperazinyl derivatives of norfloxacin

We report herein the synthesis of some N-Mannich bases in addition to different N-4 substituents of norfloxacin. The antibacterial activities of the newly synthesized compounds were evaluated and correlated with their physicochemical properties. Results revealed that some of the tested compounds exhibited better inhibitory activities than the reference antibiotic norfloxacin against Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia and Staphylococcus aureus strains. Correlation results showed that there is no single physicochemical parameter that can determine the effect of N-4 piperazinyl group on the activity of these fluoroquinolones, where lipophilicity, molecular mass and electronic factors may influence the activity.

Aminoglycoside Resistance Rates, Phenotypes, and Mechanisms of Gram-Negative Bacteria from Infected Patients in Upper Egypt

With the re-emergence of older antibiotics as valuable choices for treatment of serious infections, we studied the aminoglycoside resistance of Gram-negative bacteria isolated from patients with ear, urinary tract, skin, and gastrointestinal tract infections at Minia university hospital in Egypt. Escherichia coli (mainly from urinary tract and gastrointestinal tract infections) was the most prevalent isolate (28.57%), followed by Pseudomonas aeruginosa (25.7%) (mainly from ear discharge and skin infections). Isolates exhibited maximal resistance against streptomycin (83.4%), and minimal resistance against amikacin (17.7%) and intermediate degrees of resistance against neomycin, kanamycin, gentamicin, and tobramycin. Resistance to older aminoglycosides was higher than newer aminoglycoides. The most common aminoglycoside resistance phenotype was that of streptomycin resistance, present as a single phenotype or in combination, followed by kanamycin-neomycin as determined by interpretative reading. The resistant Pseudomonas aeruginosa strains were capable of producing aminoglycoside-modifying enzymes and using efflux as mechanisms of resistance. Using checkerboard titration method, the most frequently-observed outcome in combinations of aminoglycosides with β-lactams or quinolones was synergism. The most effective combination was amikacin with ciprofloxacin (100% Synergism), whereas the least effective combination was gentamicin with amoxicillin (53.3% Synergistic, 26.7% additive, and 20% indifferent FIC indices). Whereas the studied combinations were additive and indifferent against few of the tested strains, antagonism was never observed. The high resistance rates to aminoglycosides exhibited by Gram-negative bacteria in this study could be attributed to the selective pressure of aminoglycoside usage which could be controlled by successful implementation of infection control measures.

Antimicrobial Susceptibility Profile of Pseudomonas aeruginosa Isolates in Egypt

PURPOSE Pseudomonas aeruginosa is a leading cause of nosocomial respiratory tract, urinary tract and skin infections. Data are sparse on the antimicrobial resistance of P. aeruginosa in Egypt. We sought to detect and compare the antimicrobial susceptibility of P. aeruginosa isolates from respiratory tract, urinary tract and skin infections at 3 Egyptian hospitals. MATERIALS AND METHODS Minimum inhibitory concentrations of antibiotics were determined by the agar dilution method. RESULTS P. aeruginosa respiratory tract infections isolates were 100% resistant to ampicillin, ampicillin/sulbactam, amoxicillin, amoxicillin/clavulanate and chloramphenicol, highly resistant to cefuroxime (89%), tetracycline (89%) and azithromycin (84%), and susceptible to norfloxacin (89%), amikacin (84%) and meropenem (68%). P. aeruginosa urinary tract infection isolates were 100% resistant to ampicillin, amoxicillin, chloramphenicol, cefuroxime and tetracycline, highly resistant to amoxicillin/clavulanate (95%), azithromycin (95%), cefalexin (91%) and ampicillin/sulbactam (82%), and susceptible to amikacin (82%), meropenem (73%) and norfloxacin (64%). P. aeruginosa skin infection isolates were 100% resistant to ampicillin and amoxicillin, highly resistant to tetracycline (95%), amoxicillin/clavulanate (95%), cefalexin (87%) and azithromycin (84%), and susceptible to amikacin (87%), norfloxacin (71%) and meropenem (68%). The anti-pseudomonal effect of antibiotics varied among different infection sites only for ampicillin/sulbactam, cefoperazone or chloramphenicol but not with the other tested antibiotics. CONCLUSIONS Norfloxacin and amikacin could be used for initial therapy for P. aeruginosa mediated respiratory tract infections. Amikacin, meropenem and norfloxacin could be used for P. aeruginosa mediated urinary tract and skin infections. Such studies are essential to determine the current guidelines for empirical therapy regimens, which vary by location, and help with the establishment of effective infection control measures.

Antibiotic resistance in lactic acid bacteria isolated from some pharmaceutical and dairy products

A total of 244 lactic acid bacteria (LAB) strains were isolated from 180 dairy and pharmaceutical products that were collected from different areas in Minia governorate, Egypt. LAB were identified phenotypically on basis of morphological, physiological and biochemical characteristics. Lactobacillus isolates were further confirmed using PCR-based assay. By combination of phenotypic with molecular identification Lactobacillus spp. were found to be the dominant genus (138, 76.7%) followed by Streptococcus spp. (65, 36.1%) and Lactococcus spp. (27, 15%). Some contaminant organisms such as (Staphylococcus spp., Escherichia coli, Salmonella spp., mould and yeast) were isolated from the collected dairy samples but pharmaceutical products were free of such contaminants. Susceptibility of LAB isolates to antibiotics representing all major classes was tested by agar dilution method. Generally, LAB were highly susceptible to Beta-lactams except penicillin. Lactobacilli were resistant to vancomycin, however lactococci and streptococci proved to be very susceptible. Most strains were susceptible to tetracycline and showed a wide range of streptomycin MICs. The MICs of erythromycin and clindamycin for most of the LAB were within the normal range of susceptibility. Sixteen Lactobacillus, 8 Lactococcus and 8 Streptococcus isolates including all tetracycline and/or erythromycin resistant strains were tested for the presence of tetracycline and/or erythromycin resistant genes [tet(M) and/or erm(B)]. PCR assays shows that some resistant strains harbor tet(M) and/or erm(B) resistance genes.

Epidemiology and antimicrobial resistance of staphylococci isolated from different infectious diseases.

A total of 187 isolates from 470 clinical specimens were collected from three hospitals in El-Minia governorate and identified as 132 Staphylococcus aureus strains and 55 coagulase-negative staphylococci (CoNS) strains. Susceptibility of isolates to antimicrobial agents was tested by the agar dilution method. The isolated S. aureus strains showed low resistance to vancomycin (1.5%), amikacin (2.3%) and gatifloxacin (3.8%). Vancomycin was the most effective antibiotic against CoNS. The ampicillin-resistant isolates were tested for β-lactamase production where, 61.7% of S. aureus and 42.9% of CoNS were positive for β-lactamase enzyme. Beta-lactamase producing strains were screened for their plasmid profile using alkaline lysis method. Some of these strains carried at least one plasmid suggesting plasmid-mediated antibiotic resistance. When cells of these strains were exposed to curing agent ethidium bromide, the production of the β-lactamase was lost. Resistance by efflux was studied by a modified fluorometric assay. Addition of uncoupler carbonyl cyanide m-chlorophenylhydrazone (CCCP) increased norfloxacin accumulation in quinolone resistant S. aureus strains, suggesting endogenous energy-dependent efflux. Combinations of ciprofloxacin with four antimicrobial agents against methicillin resistant S.aureus (MRSA) strains were investigated using decimal assay for additivity (DAA) technique. Synergistic interaction was observed between ciprofloxacin and oxacillin. ciprofloxacin plus cefepime and gentamicin appeared to be additive, while ciprofloxacin plus erythromycin was antagonistic.

Evaluation of different diagnostic methods of bacterial vaginosis

Bacterial vaginosis (BV) is an ecological disorder of the vaginal microbiota that affects millions of women annually, and is associated with numerous adverse health outcomes including pre-term birth and the acquisition of sexually transmitted infections. This study aimed to determine the incidence rate of bacterial vaginosis among women and examine the effect of some risk factors and demographic features on BV incidence. Also aimed to compare between the different methods of BV diagnosis. The results revealed that from the 100 patients, 33% were diagnosed as bacterial vaginosis, 23% were having candidiasis, 8% aerobic vaginitis, 3% trichomoniasis and 33% were normal. The highest number of BV positive cases was in the age group of (26-35)Yrs, 94% of the 33 BV positive cases were using vaginal douches and 94% were married. BV positive cases using IUD were equal to BV positive cases using hormonal contraceptives including injection and tablets (12/33, 36.4%). BV was diagnosed in 33%, 38%, 36%, 30% and 34% of patients using Gram stain, culture, Amsel criteria, BV Blue test ® and qPCR respectively. When the different diagnostic methods were compared to Gram stain as a gold standard, qPCR had the highest sensitivity, accuracy and negative predictive value while BV Blue test had the highest specificity and positive predictive value.

Prevalence of Extended-Spectrum Beta-Lactamase, AmpC Beta- Lactamase, and Metallo-Beta-Lactamase among Clinical Isolates of Pseudomonas aeruginosa

Objectives : to study prevalence of ESBLs, AmpC beta‑lactamase and metallo‑beta‑lactamase among clinical isolates of P. aeruginosa . Materials and Methods : P. aeruginosa were isolated and identified by the traditional microbiological procedure, ESBLs were detected by combined disk diffusion method according CLSI recommendations, AmpC beta-lactamase was detected by iodometric methods, MBL was detected by disc potentiation test and Agar dilution method for antibiotic susceptibility testing. Results : Out of 330 samples of different types of infections, 58 were positive for P. aeruginosa . All isolates showed high resistance to most of the tested antimicrobials but showed low resistance to amikacin. Forty-two (72.4%) isolates were detected as β-lactamase producers, 16 (27.5%) isolates were positive for ESBLs while 31(53.4%) were MBL producing strains. All ESBL and MBL producers were highly resistant to the tested antimicrobials. Plasmid profile showed that 9 isolates were plasmid mediated. Conclusion : The study emphasizes a high prevalence of multidrug-resistant P. aeruginosa producing beta‑lactamase enzymes of diverse mechanisms especially in burn units. Proper antibiotic policy and measures should be taken to minimize the emergence of this multiple β‑lactamase producing pathogens and also the danger of their dissemination to other bacteria by plasmids which may carry resistance genes for other antimicrobials.

RNA protein kinase SNP at −226 C<T is a biomarker for the clearance of HCV among Egyptian patients

ABSTRACT Background: RNA-dependant protein kinase R (PKR) is a primary mediator in the defence mechanism of interferon against viral replication and pathogenesis during Hepatitis C virus (HCV) infection. In the present study, we have examined the role of Single Nucleotide Polymorphisms (SNPs) in the promoter region of PKR and the serum level of the same protein on the outcome of HCV-infected Egyptian patients. Patients and Methods: Genomic DNA was extracted from a total of 135 subjects, including 15 healthy controls, 40 HCV spontaneous resolvers (SRs), and 80 patients with chronic HCV infection. PKR genotyping was assessed using DNA sequencing. Finally, serum levels of PKR, TNF-α, INF-γ, and IL-10 were measured using ELISA technique. Results: Serum levels of PKR, TNF-α, and INF-γ showed a significant increase in SRs as compared to chronic HCV patients. On the other hand, serum levels of IL-10 were significantly higher in chronic HCV patients compared to SRs. The present study demonstrated two novel SNPs in the PKR promoter region: at −226 C/T and −141 C/G. The PKR SNP at −226 C < T correlated with HCV-infected patients (genotype 4a) outcome among Egyptians. Our data showed the unique presence of the TT genotype in SRs group (three patients: 7.5%) in PKR −226 C/T. Interestingly, subjects with the TT genotype were more likely to clear their HCV infection than those with the CC genotype. Conclusion: Our work provides more detail about PKR gene polymorphism in HCV genotype 4a as a new clinical tool for anticipating HCV-4a infection outcome.

Impact of IL-27p28 (rs153109) and TNF-α (rs1800629) Genetic Polymorphisms on the Progression of HCV Infection in Egyptian Patients

ABSTRACT Background: Hepatitis C virus (HCV) is a universal health problem. HCV infection may proceed to liver fibrosis, cirrhosis, and eventually hepatocellular carcinoma (HCC). The latest is the third leading global cause of cancer-related mortality. Cytokines including IL-27 and TNF-α play a major role as a link between innate and adaptive immunity which in turn deduct the outcome of HCV infection. Aim: The present study examined the role of both (-964 A/G) single-nucleotide polymorphism (SNP) of IL-27p28 rs153109 and (-308 G/A) SNP of TNF-α rs1800629 on the progression of HCV infection in genotype 4a infected patients. Patients and Methods: The patients enrolled in the study were divided into three main groups group I: 38 fibrotic patients, group II: 51 cirrhotic patients, and finally group III: 29 HCC patients. Sixteen healthy volunteers were used as controls. IL-27p28 rs153109 and TNF-α rs1800629 genotyping were performed using polymerase chain reaction-restriction fragment length polymorphism assay. Results: There was no statistically significant difference between the studied groups regarding the IL-27p28 genotypes. However, TNF-α (-308) studied polymorphism showed a significant difference between the HCC and fibrosis group (p = 0.00), and also between the cirrhosis and fibrosis group (p = 0.031) revealing that AA genotype is the genotype of risk. Furthermore, the association found between allele frequencies of two studied SNPs and the four studied groups were non-significant. Conclusion: TNF-α rs1800629 polymorphism is a potential genetic-susceptibility factor for HCV related cirrhosis and HCC progression.

Extended infusion versus intermittent infusion of imipenem in the treatment of ventilator-associated pneumonia

BACKGROUND Mechanical ventilation support can be the main source of ventilator-associated pneumonia (VAP). VAP is a serious infection that may be associated with dangerous gram-negative bacteria mainly, and it leads to an increase in the mortality in the intensive care unit (ICU). Imipenem is one of the strongest antibiotics now available for treating VAP which is associated with gram-negative and gram-positive bacteria, and it belongs to beta-lactam antibiotic group (carbapenem). OBJECTIVE This study tried to investigate the efficacy of imipenem against VAP when it was infused within 180 min versus the efficacy when it was infused within 30-60 min. SETTING This study was conducted in main ICU in general hospital which consists of surgical and medical beds within 2 years. One hundred and eighty-seven patients were enrolled on it. METHOD This study is a retrospective cohort which was conducted within 2 years. The efficacy of imipenem which was administered by intermittent infusion (30-60 min) within first year was compared with the efficacy of imipenem which was administered by extended infusion (180 min) within second year in the field of VAP curing and cost reduction. All data were collected retrospectively from patient medical files and were statistically analyzed by SPSS version 20. MAIN OUTCOME The study was designed to measure clinical and cost reduction outcomes, mortality and hospital stay. RESULTS The results indicated that there is a significant decrease in mortality, number of recurrent infection, and ICU stay length, and the number of mechanical ventilator days was associated with extended imipenem infusion during the second year of the study. CONCLUSION The use of imipenem with extended infusion over 3 hours enhances its clinical outcomes in the treatment of VAP.