scholarly journals Development of Staphylococcus Enzybiotics: The Ph28 Gene of Staphylococcus epidermidis Phage PH15 Is a Two-Domain Endolysin

Antibiotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 148
Author(s):  
Magdy Mohamed Muharram ◽  
Ashraf Tawfik Abulhamd ◽  
Mohammed F. Aldawsari ◽  
Mohamed Hamed Alqarni ◽  
Nikolaos E. Labrou

Given the worldwide increase in antibiotic resistant bacteria, bacteriophage derived endolysins represent a very promising new alternative class of antibacterials in the fight against infectious diseases. Endolysins are able to degrade the prokaryotic cell wall, and therefore have potential to be exploited for biotechnological and medical purposes. Staphylococcus epidermidis is a Gram-positive multidrug-resistant (MDR) bacterium of human skin. It is a health concern as it is involved in nosocomial infections. Genome-based screening approach of the complete genome of Staphylococcus virus PH15 allowed the identification of an endolysin gene (Ph28; NCBI accession number: YP_950690). Bioinformatics analysis of the Ph28 protein predicted that it is a two-domain enzyme composed by a CHAP (22-112) and MurNAc-LAA (171-349) domain. Phylogenetic analysis and molecular modelling studies revealed the structural and evolutionary features of both domains. The MurNAc-LAA domain was cloned, and expressed in E. coli BL21 (DE3). In turbidity reduction assays, the recombinant enzyme can lyse more efficiently untreated S. epidermidis cells, compared to other Staphylococcus strains, suggesting enhanced specificity for S. epidermidis. These results suggest that the MurNAc-LAA domain from Ph28 endolysin may represent a promising new enzybiotic.

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 466
Author(s):  
Herbert Galler ◽  
Josefa Luxner ◽  
Christian Petternel ◽  
Franz F. Reinthaler ◽  
Juliana Habib ◽  
...  

In recent years, antibiotic-resistant bacteria with an impact on human health, such as extended spectrum β-lactamase (ESBL)-containing Enterobacteriaceae, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE), have become more common in food. This is due to the use of antibiotics in animal husbandry, which leads to the promotion of antibiotic resistance and thus also makes food a source of such resistant bacteria. Most studies dealing with this issue usually focus on the animals or processed food products to examine the antibiotic resistant bacteria. This study investigated the intestine as another main habitat besides the skin for multiresistant bacteria. For this purpose, faeces samples were taken directly from the intestines of swine (n = 71) and broiler (n = 100) during the slaughter process and analysed. All samples were from animals fed in Austria and slaughtered in Austrian slaughterhouses for food production. The samples were examined for the presence of ESBL-producing Enterobacteriaceae, MRSA, MRCoNS and VRE. The resistance genes of the isolated bacteria were detected and sequenced by PCR. Phenotypic ESBL-producing Escherichia coli could be isolated in 10% of broiler casings (10 out of 100) and 43.6% of swine casings (31 out of 71). In line with previous studies, the results of this study showed that CTX-M-1 was the dominant ESBL produced by E. coli from swine (n = 25, 83.3%) and SHV-12 from broilers (n = 13, 81.3%). Overall, the frequency of positive samples with multidrug-resistant bacteria was lower than in most comparable studies focusing on meat products.


Author(s):  
Nahla Omer Eltai ◽  
Hadi M. Yassine ◽  
Sara H. Al-Hadidi ◽  
Tahra ElObied ◽  
Asmaa A. Al Thani ◽  
...  

The dissemination of antimicrobial resistance (AMR) bacteria has been associated with the inappropriate use of antibiotics in both humans and animals and with the consumption of food contaminated with resistant bacteria. In particular, the use of antibiotics as prophylactic and growth promotion purposes in food-producing animals has rendered many of the antibiotics ineffective. The increased global prevalence of AMR poses a significant threat to the safety of the world’s food supply. Objectives: This study aims at determining the prevalence of antibiotic-resistant Escherichia coli (E. coli) isolated from local and imported retail chicken meat in Qatar. Methodology: A total of 270 whole chicken carcasses were obtained from three different hypermarket stores in Qatar. A total of 216 E. coli were isolated and subjected to antibiotic susceptibility testing against 18 relevant antibiotics using disc diffusion and micro- dilution methods. Furthermore, extended-spectrum β-lactamase (ESBL) production was determined via a double-disc synergetic test. Isolates harboring colistin resistance were confirmed using multiplex-PCR and DNA sequencing. Results: Nearly 89% (192/216) of the isolates were resistant to at least one antibiotics. In general, isolates showed relatively higher resistance to sulfamethoxazole (62%), tetracycline (59.7%), ampicillin and trimethoprim (52.3%), ciprofloxacin (47.7%), cephalothin, and colistin (31.9%). On the other hand, less resistance was recorded against amoxicillin/clavulanic acid (6%), ceftriaxone (5.1%), nitrofurantoin (4.2%) and piperacillin/tazobactam (4.2%), cefepime (2.3%), meropenem (1.4%), ertapenem (0.9%), and amikacin (0.9%). Nine isolates (4.2%) were ESBL producers. Furthermore, 63.4% were multidrug-resistant (MDR). The percentage of MDR, ESBL producers, and colistin-resistant isolates was significantly higher among local isolates compared to imported chicken samples. Conclusion: We reported a remarkably high percentage of the antibiotic-resistant E. coli in chicken meat sold at retail in Qatar. The high percentage of MDR and colistin isolates is troublesome to the food safety of raw chicken meat and the potential of antibiotic resistance spread to public health. Our findings support the need for the implementation of one health approach to address the spread of antimicrobial resistance and the need for a collaborative solution.


Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1190
Author(s):  
Siqin Liu ◽  
Agnes Kilonzo-Nthenge ◽  
Samuel N. Nahashon ◽  
Bharat Pokharel ◽  
Abdullah Ibn Mafiz ◽  
...  

This study investigated the prevalence of antimicrobial-resistant bacteria in retail edible offal and muscle meats in Nashville, Tennessee. A total of 348 retail meats (160 edible offal and 188 muscle) were analyzed for Salmonella enterica serovar, Campylobacter, Escherichia coli, E. coli O157:H7, and enterococci. Bacteria was identified using biochemical and PCR methods. Salmonella enterica serovar (4.4% and 4.3%), Campylobacter (1.9% and 1.1%), E. coli (79.4% and 89.4%), and enterococci (88.1% and 95.7%) was detected in offal and muscle meats, respectively. Chicken liver (9.7%) was most frequently contaminated with Salmonella enterica serovar, followed by ground chicken (6.9%) and chicken wings (4.2%). No Salmonella enterica serovar was detected in beef liver, beef tripe, and ground beef. The prevalence of Campylobacter was 6.9%, 2.3%, and 1.4% in beef liver, ground beef, and ground chicken, respectively. None of the meats were positive for E. coli O157:H7. Resistance of isolates was significantly (p < 0.05) highest in erythromycin (98.3%; 99.1%), followed by tetracycline (94%; 98.3%), vancomycin (88.8%; 92.2%) as compared to chloramphenicol (43.1%; 53.9%), amoxicillin/clavulanic (43.5%; 45.7%), and ciprofloxacin (45.7%; 55.7%) in offal and muscle meats, respectively. Imipenem showed the lowest resistance (0%; 0.9%). A total of 41 multidrug-resistant patterns were displayed. Edible offal could be a source of antibiotic-resistant bacteria.


2021 ◽  
Author(s):  
Jennifer Moussa ◽  
Edmond Abboud ◽  
Sima Tokajian

AbstractThe prevalence of antibiotic-resistant bacteria in surface water in Lebanon is a growing concern and understanding the mechanisms of the spread of resistance determinants is essential. We aimed at studying the occurrence of resistant organisms and determinants in surface water sources in Lebanon and understanding their mobilization and transmission. Water samples were collected from five major rivers in Lebanon. 91 isolates were recovered out of which 25 were multidrug-resistant (MDR) and accordingly were further characterized. Escherichia coli and Klebsiella pneumoniae were the most commonly identified MDR isolates. Conjugation assays coupled with in silico plasmid analysis were performed and validated using PCR-based replicon typing (PBRT) to identify and confirm incompatibility groups and the localization of β-lactamase encoding genes. E. coli EC23 carried a blaNDM-5 gene on a conjugative, multireplicon plasmid, while blaCTX-M-15 and blaTEM-1B were detected in the majority of the MDR isolates. Different ST types were identified including the highly virulent E. coli ST131. Our results showed a common occurrence of bacterial contaminants in surface water and an increase in the risk for the dissemination of resistance determinants exacerbated with the ongoing intensified population mobility in Lebanon and the widespread lack of wastewater treatment.


Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1587
Author(s):  
Feng Wang ◽  
Xiaohang Liu ◽  
Zhengyu Deng ◽  
Yao Zhang ◽  
Xinyu Ji ◽  
...  

With the increasing spread of multidrug-resistant bacterial pathogens, it is of great importance to develop alternatives to conventional antibiotics. Here, we report the generation of a chimeric phage lysin, MLTphg, which was assembled by joining the lysins derived from Meiothermus bacteriophage MMP7 and Thermus bacteriophage TSP4 with a flexible linker via chimeolysin engineering. As a potential antimicrobial agent, MLTphg can be obtained by overproduction in Escherichia coli BL21(DE3) cells and the following Ni-affinity chromatography. Finally, we recovered about 40 ± 1.9 mg of MLTphg from 1 L of the host E. coli BL21(DE3) culture. The purified MLTphg showed peak activity against Staphylococcus aureus ATCC6538 between 35 and 40 °C, and maintained approximately 44.5 ± 2.1% activity at room temperature (25 °C). Moreover, as a produced chimera, it exhibited considerably improved bactericidal activity against Staphylococcus aureus (2.9 ± 0.1 log10 reduction was observed upon 40 nM MLTphg treatment at 37 °C for 30 min) and also a group of antibiotic-resistant bacteria compared to its parental lysins, TSPphg and MMPphg. In the current age of growing antibiotic resistance, our results provide an engineering basis for developing phage lysins as novel antimicrobial agents and shed light on bacteriophage-based strategies to tackle bacterial infections.


2021 ◽  
Author(s):  
Tatsuya Nakayama ◽  
Le Thi Hien ◽  
Ngo Thanh Phong ◽  
Doan Nguyen Minh Tran ◽  
Oanh Thi Hoang Nguyen ◽  
...  

Abstract Although the spread of plasmid-mediated antibiotic-resistant bacteria is a public health concern, food contamination with plasmid-mediated antibiotic-resistant Escherichia coli has not been well investigated in Vietnam. The aim of this study was to describe the prevalence of colistin-resistant, carbapenem-resistant and endemic blaCTX−M in extended-spectrum β-lactamase (ESBL)-producing E. coli isolates. Colistin- and carbapenem-resistant ESBL-producing E. coli were isolated from chickens in Vietnam and Japan. The results showed that 52% and 93% of Vietnamese chicken was isolated with colistin-resistant and AmpC/ESBL-producing E. coli, respectively, while 52.7% of Japanese chickens were isolated with AmpC/ESBL-producing E. coli. Carbapenem-resistant E. coli has not been isolated in Vietnam or Japan. Genotyping revealed that colistin-resistant E. coli harboured mcr-1, and most of the AmpC/ESBL-related genes were blaCTX−M−55 and blaCTX−M−65 together with blaTEM in Vietnamese chickens, and blaCMY−2 in Japanese chickens. Multidrug resistance analysis showed that ESBL-producing E. coli isolates were more resistant to quinolones, streptomycin, and chloramphenicol compared with colistin-resistant E. coli isolates from Vietnam, suggesting selection in ESBL-producing E. coli for multiple antibiotic resistance genes. In conclusion, colistin-resistant E. coli was detected in about half of the chicken meat samples, the majority of which were found to harbour mcr-1. The high prevalence of ESBL-producing E. coli has remained constant across the last five years, and the predominant blaCTX−M for ESBL-producing E. coli was found to be blaCTX−M−55 or blaCTX−M−65, with the coexistence of blaTEM in Vietnam. Our results can be implemented in monitoring systems to combat the development of antimicrobial resistance.


2018 ◽  
Vol 11 ◽  
pp. 117863611878692 ◽  
Author(s):  
Ama Okyere ◽  
Dayna Bishoff ◽  
Micah O Oyaro ◽  
Nadim J Ajami ◽  
Charles Darkoh

Fish has been an important source of proteins, essential vitamins, and low saturated fats for centuries. However, improperly handled fish can expose consumers to infectious bacteria, including difficult to treat multidrug-resistant pathogens. With the goal to investigate the existence of disease-causing and antibiotic-resistant bacteria, we examined bacterial communities present on various types of fish purchased from supermarkets in Houston, Texas, USA. The bacterial communities were characterized by selective phenotypic culture methods, 16S ribosomal RNA gene sequencing, and antibiotic susceptibility testing. The results revealed the presence of different bacterial communities on the fish samples examined. The bacterial communities were not significantly different between the supermarkets sampled. The following presumptive human pathogens were isolated on the fish samples: Escherichia coli (67%), enterohemorrhagic E. coli (31%), Shigella and Salmonella species (28%), Listeria species (29%), and Staphylococcus aureus (28%). Drug sensitivity assays showed resistance to commonly prescribed antibiotics ciprofloxacin, gentamicin, and vancomycin. Out of a total of 99 E. coli samples tested, 41.4% were resistant to ciprofloxacin, whereas 33.3% were resistant to gentamicin. Of the total of 31 S. aureus isolates tested, 87% were resistant to ciprofloxacin, whereas 61.3% were resistant to vancomycin. Moreover, some of the E. coli strains were resistant to both ciprofloxacin and gentamicin (28%), whereas 49% of the S. aureus isolates were resistant to both ciprofloxacin and vancomycin. These results highlight the prevalence of antimicrobial-resistant foodborne pathogens on fish purchased from the supermarkets and underscore the risk associated with improper handling of fish.


2021 ◽  
Author(s):  
Matthew Mitcheltree ◽  
Amarnath Pisipati ◽  
Egor A. Syroegin ◽  
Katherine J. Silvestre ◽  
Dorota Klepacki ◽  
...  

The dearth of new medicines effective against antibiotic-resistant bacteria presents a growing global public health concern. For more than five decades, the search for new antibiotics has relied heavily upon the chemical modification of natural products (semi-synthesis), a method ill-equipped to combat rapidly evolving resistance threats. Semi-synthetic modifications are typically of limited scope within polyfunctional antibiotics, usually increase molecular weight, and seldom permit modifications of the underlying scaffold. When properly designed, fully synthetic routes can easily address these shortcomings. Here we report the structure-guided design and component-based synthesis of a rigid oxepanoproline scaffold which, when linked to the aminooctose residue of clindamycin, produces an antibiotic of exceptional potency and spectrum of activity, here named iboxamycin. Iboxamycin is effective in strains expressing Erm and Cfr rRNA methyltransferase enzymes, products of genes that confer resistance to all clinically relevant antibiotics targeting the large ribosomal subunit, namely macrolides, lincosamides, phenicols, oxazolidinones, pleuromutilins, and streptogramins. X-ray crystallographic studies of iboxamycin in complex with the native 70S bacterial ribosome, as well as the Erm-methylated 70S ribosome, uncover the structural basis for this enhanced activity, including an unforeseen and unprecedented displacement of upon antibiotic binding. In mice, iboxamycin is orally bioavailable, safe, and effective in treating bacterial infections, testifying to the capacity for chemical synthesis to provide new antibiotics in an era of rising resistance.


2020 ◽  
Author(s):  
Roseline Ekiomado Uzeh ◽  
Bamidele Tolulope Odumosu ◽  
Fadekemisola Adewumi

Abstract Background The presence of antibiotic resistant microorganisms in food is of great concern globally. This research was carried out to detect and characterize plasmid carriage and profiles among members of Enterobacteriaceae from different meat types in Nigeria. Method From a total of 80 meat samples comprising of mutton, pork, beef and chicken, organisms belonging to the family Enterobacteriaceae were isolated by standard procedures and identified by API 20E system. Antibiotics susceptibilities testing (AST) against selected classes of antimicrobial agents and plasmid extraction was carried out by disc diffusion and alkaline lysis methods respectively. Results One-hundred and ten Enterobacteriaceae were isolated, species identification revealed isolates belonging to 7 genera comprising of Escherichia, Enterobacter, Klebsiella, Citrobacter, Proteus, Salmonella and Serratia. Overall resistance of the organisms to amoxycillin/clavulanic acid was 91 (82.7%), streptomycin 85 (75.7%) and perfloxacin 74 (67.2%) while ofloxacin had the highest susceptibility rate (91.8%). Plasmids profiling revealed ranges of plasmids from 1 to 3 copies with estimated sizes range of 700bp to 1.1kb among E. coli, K. pneumoniae, E. aerogenes and Proteus mirabilis. All the isolates with plasmids were multidrug resistant and were isolated from chicken except a strain of E. coli from pork which harboured a single plasmid copy suggesting these meat as reservoirs for antibiotic resistant bacteria. Conclusion Our findings revealed high level of meat contamination with antibiotic resistant Enterobacteriaceae harbouring resistant plasmids. An integrated surveillance system and safety practice must be ensured among the processors and retailers


2021 ◽  
Author(s):  
Matthew Mitcheltree ◽  
Amarnath Pisipati ◽  
Egor A. Syroegin ◽  
Katherine J. Silvestre ◽  
Dorota Klepacki ◽  
...  

The dearth of new medicines effective against antibiotic-resistant bacteria presents a growing global public health concern. For more than five decades, the search for new antibiotics has relied heavily upon the chemical modification of natural products (semi-synthesis), a method ill-equipped to combat rapidly evolving resistance threats. Semi-synthetic modifications are typically of limited scope within polyfunctional antibiotics, usually increase molecular weight, and seldom permit modifications of the underlying scaffold. When properly designed, fully synthetic routes can easily address these shortcomings. Here we report the structure-guided design and component-based synthesis of a rigid oxepanoproline scaffold which, when linked to the aminooctose residue of clindamycin, produces an antibiotic of exceptional potency and spectrum of activity, here named iboxamycin. Iboxamycin is effective in strains expressing Erm and Cfr rRNA methyltransferase enzymes, products of genes that confer resistance to all clinically relevant antibiotics targeting the large ribosomal subunit, namely macrolides, lincosamides, phenicols, oxazolidinones, pleuromutilins, and streptogramins. X-ray crystallographic studies of iboxamycin in complex with the native 70S bacterial ribosome, as well as the Erm-methylated 70S ribosome, uncover the structural basis for this enhanced activity, including an unforeseen and unprecedented displacement of upon antibiotic binding. In mice, iboxamycin is orally bioavailable, safe, and effective in treating bacterial infections, testifying to the capacity for chemical synthesis to provide new antibiotics in an era of rising resistance.


Sign in / Sign up

Export Citation Format

Share Document