Isolation and biocontrol of bacteriophages from wastewater in the city of Lomé, Togo: potential application as a novel source for antimicrobial therapy

Background: Bacteriophages offer one of the most promising solutions to the challenges of antimicrobial resistance in bacteria. The aim of this study is to investigate bacteriophages as a source of new antimicrobial therapy. Methodology: Waste water samples were randomly collected from 8 different locations in the city of Lomé for bacteriophage isolation. The phages were isolated using multi-resistant clinical isolates (Escherichia coli 1642 and Staphylococcus aureus 0868) as hosts by means of a spot test. The host range of the phages was determined also by a spot test using 8 other clinical bacterial isolates including two reference strains (E. coli ATCC 25922 and S. aureus ATCC 29213). The virulence of the phages and their effects on bacterial growth were assessed by in vitro experiments using E. coli 1642 BBec phage suspension. Results: Isolation of phages by the spot test was positive only with the host E. coli 1642. A reduced host range was observed with the other bacteria. The BBec phage suspension showed a titer of 1.6 x 107 PFU/ml. Virulence studies revealed a latency time of less than 10 minutes, a degree of absorption of 87% and a burst size of 63 PFU/cell. The effect of BBec phage suspension on E. coli 1642 showed an almost total reduction in the population of E. coli 1642 after 4 hours. Conclusion: This study provided scientific data showing the antibacterial effect of a phage suspension (BBec) on a multi-resistant clinical isolate of E. coli 1642. This phage could therefore be explored as a candidate for the development of new antibacterial therapies.

Prevalence of multi-drug resistant Pseudomonas aeruginosa isolated from selected residential sewages in Dutsin-Ma, Katsina State, Nigeria

The global surge in Multidrug resistant (MDR) bacteria is an issue of great concern. Pseudomonas aeruginosa has been implicated in several nosocomial infections, where it has caused grave complications in immunocompromised patients. This is the first study to report the prevalence of MDR P. aeruginosa isolated from residential sewage in Dutsin-Ma, Katsina State, Nigeria. Pseudomonads count, isolation, biochemical characterization and antibiogram were carried out using standard microbiological procedures. This study examined sixty (60) samples from selected residential sewage in the study site collected at different intervals between July and September 2021. A total of 40 (66.7%) P. aeruginosa were isolated from the analyzed sewage samples. The highest (2.84x104) pseudomonad count was recorded from sewage samples collected from Kadangaru. Pseudomonas aeruginosa isolates from this sample site showed the highest (100%) resistance to cephalosporins (cefuroxime) and nitrofurantoin. Similarly, isolates from Miami area also demonstrated the highest (95%) resistance to a cephalosporin (ceftazidime). All (100%) isolates used in this study showed MDR resistance to tested antibiotics. The occurrence of MDR P. aeruginosa from a residential sewage site that may contaminate drinking water sources in the study area is of public health threat to the inhabitants. Surveillance and molecular epidemiology of antibiotics resistant bacteria are urgently needed in the study area.

Evaluation of antibacterial activity of silver nanoparticles against multidrug-resistant gram negative bacilli clinical isolates from Zagazig University Hospitals

Background: The growing incidence of multidrug resistant (MDR) bacterial infections has become a public health crisis. This work aims to evaluate the in-vitro activity of silver nanoparticles (AgNPs), alone and in combination with the antimicrobials amikacin and ceftazidime, against MDR Gram-negative bacilli (GNB) isolated from clinical cases in Zagazig University Hospitals. Methods: In a cross sectional study, MDR GNB were isolated from different clinical specimens and were tested to determine the minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC) and bactericidal activity of AgNPs using broth microdilution method. The effect of combining subMIC levels of AgNPs (MIC/2 and MIC/4) with amikacin and ceftazidime, was also determined by broth microdilution. Results: A total of 63 MDR GNB was obtained during the study period (22 E. coli, 17 Klebsiella, 15 Pseudomonas aeruginosa and 9 Acinetobacter isolates). AgNPs demonstrated a bactericidal effect on all tested isolates with an MBC/MIC ratio of less than 4. When combined with amikacin, a synergistic effect was demonstrated on all tested E.coli and Klebsiella isolates at AgNPs MIC/2 and on 45.4%, 40% and 77.8% of E.coli, P.aeruginosa and Acinetobacter isolates, respectively at MIC/4. In combination with ceftazidime, AgNPs exhibited a synergistic effect on 100% of E. coli and 88.2% Klebsiella at both MIC/2 and MIC/4 and on 40% of P. aeruginosa isolates at AgNPs MIC/4. Conclusions: AgNPs exert a bactericidal activity on MDR GNB as well as a synergistic effect when combined with amikacin and ceftazidime suggesting them as a new weapon in the war against MDR GNB

Multi-drug resistant bacteria and associated factors among reproductive age women with significant bacteriuria

Background: Urinary tract infection (UTI), an infection that disproportionately affects women, is commonly caused by bacteria. Emergence of multi-drug resistant urinary tract infections is a serious health issue with significant maternal morbidity and mortality. Objective: The aim of this study was to assess the prevalence of multi-drug resistant bacteria and associated factors among reproductive age women with significant bacteriuria. Methods: Cross-sectional study was conducted from April to August 2016 on 424 study subjects in Jimma University Specialized Hospital. Data were collected using pretested questionnaire. Morning midstream urine samples were collected and processed following standard operating procedures. Antimicrobial susceptibility testing was done following Clinical Laboratory Standards Institute 2014 guidelines. Samples were tested for cell surface hydrophobicity, biofilm production, extended spectrum betalactamases and carbapenemases production. Results: The prevalence of UTI among suspected reproductive age women was 22.9%. E. coli was the most frequent isolate with a rate of 57% among isolated bacteria followed by Klebsiella species (24.7%). Over 90% of the isolates were multi-drug resistant. Resistance pattern for ampicillin was 100% followed by ticarcillin (92.4%) and colistin (86%) while less resistance rate was found for imipenem(13%). Multivariate analysis revealed that risk factors such as previous history of hospitalization, extended spectrum betalactamase production and strong biofilm production were significantly associated with multidrug resistance (p <0.05). Conclusion: The prevalence of multi-drug resistance (MDR) among isolates of UTI in the study was high and this correlates with the prevalence of virulence phenotypes. Gram-negative organisms were the most common causes of UTIs

High burden of nosocomial infections caused by multi-drug resistant pathogens in pediatric patients at hawassa university comprehensive specialized hospital

Background: Pediatric patients are at increased risk of nosocomial infections with multi-drug resistant pathogens which are more prevalent in the hospital environment. The aim of this study was to determine the prevalence of nosocomial infections, antibiotic resistance pattern of bacterial isolates and associated factors in pediatric patients. Methods: This was a cross-sectional study conducted from March to August, 2016. Data included sociodemographic and clinical variables in patients clinically suspected of having nosocomial infections and collected using a structured questionnaire. Bacterial identification and antimicrobial susceptibility test was done with standard microbiological methods. Data were analyzed with SPSS version 20 and p value < 0.05 was considered to be statistically significant. Results: Out of 939 children admitted to the hospital, 384 patients (40.9%) were clinically suspected and had 462 nosocomial infections. Blood stream infection was the most common site of nosocomial infections. Culture confirmed nosocomial infections were reported in 82 patients (21.4%; 95% CI, 17.2-25.8%) with 88 isolates. Among the most frequently isolated bacteria, 21 (23.9%) were Klebsiella spp, and 16 (18.2%) were S. aureus, 62.5% of which were methicillin resistant. Among all bacterial pathogens, 88.9% were multi-drug resistant. Extremely high (97.9%) multi-drug resistance was associated with Gram negative bacteria. Among these, all isolates, except E. coli, were 100% multi-drug resistant. Long hospital stay and malnutrition were significantly associated with nosocomial infections. Conclusion: The high prevalence of nosocomial infections with multi-drug resistant bacteria suggests the need for proper implementation of the nosocomial infections prevention and control measures

Multidrug resistance patterns and multiple antibiotic resistance index of salmonella species isolated from Waste Dumps in Zaria Metropolis, Nigeria

ABSTRACT: Several items containing residual antimicrobial agents are disposed of in dumpsites, placing a pressure on the microbial flora and a potential for development of resistance in these microorganisms. Multidrug resistance patterns and multiple antibiotic resistance index of Salmonella spp. isolated from waste dumps in Zaria Metropolis were thus assayed in this study using one hundred and twelve (112) soil samples collected from four waste dumpsites located in Sabon-Gari, Samaru, Tudun-Wada and Zaria City. Salmonella spp. were isolated by culture methods on selective media and characterized using a series of biochemical tests. The isolates were confirmed using microgen identification kits. Results were statistically analysed using percentages. The antibiotic resistance patterns were determined, using the disc-diffusion method. Ten antibiotics belonging to eight different classes, namely B-lactams, aminoglycosides, tetracycline, cephalosporins, fluoroquinolone, Nitrofurantoins, sulphonamides, and phenicols were tested. The result of the study revealed that 57.2% of the isolates exhibited multidrug resistance (MDR) taken as resistance to four or more antibiotics tested. On the other hand, all the isolates showed 100% susceptibility to Chloramphenicol (30µg) and Gentamicin (30µg) while 76.2% had Multiple Antibiotic Resistance (MAR) Index of 0.2 and above. The isolates showing resistance to the highest number of antibiotics were obtained from refuse dumpsites in Zaria City while an isolate from Sabon-Gari was found to be resistant to six antibiotics. These results could be indicative of possible disposal of these drug residues in the waste dump locations making them hot spots for development of resistance

Prevalence and antibiotic resistance profiles of extended spectrum ß-lactamase-producing Escherichia coli among paediatric patients with urinary tract infection in St. Patricks' Hospital, Mile Four, Abakaliki, Ebonyi State, Nigeria

Background: The extended spectrum beta-lactamase (ESBL)-producing Escherichia coli strains which have been implicated in septicaemia among hospitalized children is a serious concern due to their high resistance rates to commonly used antimicrobial agents. The objective of this study was to determine the prevalence and antibiotic susceptibility of urinary ESBL-producing E. coli in paediatric patients who had clinical evidence of urinary tract infections (UTI). Methodology: Clean catch specimens of urine collected from 100 eligible paediatric patients with clinical evidence of UTI in St. Patricks' Hospital, Mile Four, Abakaliki, Ebonyi State, were cultured for isolation of E. coli using standard bacteriological techniques. Isolates were confirmed for ESBL production by double disk synergy test (DDST), and antibiotic susceptibility of the ESBL-producing ones was determined by the modified Kirby Bauer disk diffusion method. Results: Twenty one (21%) E. coli were isolated out of which 11 (52 %) were ESBL producers, all of which were totally resistant (100%) to cefotaxime, ticarcillin and sulfamethoxazole-trimethoprim, 85% to aztreonam and 83% to ceftazidime. The multiple antibiotic resistance index (MARI) values ranged from 0.4 to 0.9, which implies high usage of antimicrobials Conclusion: The high prevalence of multi-drug resistant ESBL-producing E. coli obtained in this study shows that there has been overuse (abuse or misuse) of antibiotics in the study area. There is need for antimicrobial stewardship programme that will ensure prudent use of antimicrobial agents to forestall the emergence and spread of multi-drug resistant bacteria

Frequence et profil de sensibilite aux antibiotiques des bacteries isolees des hemocultures au CHU de Mahdia

L'objectif de notre etude etait de determiner l'epidemiologie et le profil desensibilite aux antibiotiques des bacteries isolees des hemocultures dans le CHUde Mahdia; afin d'optimiser l'antibiotherapie probabiliste utilisee en premiere intention.Cette etude retrospective a ete realisee sur une periode de seize mois (Jui ll et2007 a Octobre 2008) et a concerne 398 isolats. Cinquante neuf pourcent des isolats etaient des bacilles a Gram negatif (BGN) dont 83;2d'enterobacteries. Les cocci a Gram positif representaient 39;7avec predominance de staphylocoques a coagulase negative (61;2). Les BGN non fermentant representaient 16;8. La resistance a l'oxacilline etait de 34;2pour les staphylocoques a coagulase negative. Les enterobacteries etaient resistantes aux C3G dans 50;5. Le taux de resistance de l'Acinetobacter baumannii etait de 62a la ceftazidime et de 51a l'imipeneme. Celui de Pseudomonas aeruginosa etait; respectivement de 35;3et de 18;7. Une surveillance epidemiologique des bacteriemies est necessaire; a l'echelle d'un hopital; pour mieux guider l'antibiotherapie probabiliste