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Salmonella , a major foodborne pathogen, causes severe gastrointestinal disease in people and animals worldwide. Plasmid-borne mcr-1 , which confers colistin resistance in Salmonella, has significant epidemiological interest for public health safety. Here, we report the first evidence of mcr-1 -mediated colistin resistance in one multidrug-resistant strain，namely 16062 in this study, from 355 Salmonella isolates collected for Jiaxing foodborne pathogen monitoring in Zhejiang Province in 2015-2019. In addition to colistin, 16062 displayed multidrug resistance to various antimicrobials (β-lactams, quinolone, sulfonamide, florfenicol, ampicillin, streptomycin, nalidixic acid, aminoglycoside, and trimethoprim-sulfamethox). The mcr-1 -carrying IncX4 plasmid (p16062-MCR) in this study shares a conserved structure with other mcr -IncX4 plasmids. We found that other antimicrobial-resistance genes ( aac(6')-Ib-cr , aadA1 , aadA2 , aph(3')-Ia , oqxA , oqxB , sul1 , and cmlA1 ) are located on p16062-cmlA, an atypical IncHI2 plasmid, in isolate 16062. This is the first identification of transferable colistin resistance in foodborne Salmonella isolate collected in Jiaxing city, the 5-year monitoring of which revealed limited dissemination. By determining the genetic features of the plasmid vehicle, the characteristics of transferable mcr genes circulating in isolates from Jiaxing are now clearer.

Murray-Darling Freshwater Research CentreMDFRC item.The antibiotic resistance of bacteria from the water column of various rivers and billabongs in north-eastern Victoria was studied during 1988-91. Two indices were used as measures of resistance: conventional disc-sensitivity tests with culturable bacteria, and the effect of antibiotics on the uptake of 14C-glucose and 14C-amino acids by native bacterial assemblages. Culturable bacteria were resistant to ampicillin, methicillin and penicillin but generally sensitive to nalidixic acid, neomycin, streptomycin, sulfafurazole and tetracycline. Responses to chloramphenicol, erythromycin, nitrofurantoin and sulfamethizole were variable. Bacteria isolated from rivers were more resistant to antibiotics than were those isolated from billabongs. Methicillin, even at 200 mg L-1, had little effect on the uptake of 14C-labelled compounds. Nalidic acid (20 mg L-1) also was ineffective unless lengthy pre-incubations (24 h) were used. Chloramphenicol and tetracycline at 20 mg L-1 markedly reduced amino acid uptake but not glucose uptake. The widespread antibiotic resistance of aquatic bacteria casts doubt on the suitability of these compounds to selectively inhibit the prokaryotic component in ecological studies and may be cause for concern regarding the spread of antibiotic resistance through natural aquatic communities.

Highlights • Different fishes were collected and were subjected to form an in vitro biofilm. • Huge array (up to 107 cfu/ml or g) of pathogenic bacteria. • Few of the isolates were sensitive and few were resistant against the antibiotics but after bio-film formation all the species acquired resistance., Background The ability of many bacteria to adhere on the host surfaces and forming biofilms has major implications in a wide variety of industries including the food industry, where biofilms may create a persistent source of contamination. In the same environmental condition, the multiple bacterial species can closely interact with each other and may easily enhance their drug resistance capability, which finally increases the multi-drug resistant (MDR) attribute of the species. Objective The present study examined whether the mixed-species biofilm possesses any impact on the enhancement of the antibiotic resistance of the planktonic or single-cell bacterial isolates present in the fish samples. Methods In this regard, Cyprinus rubrofuscus (Koi), Heteropneustes fossilis (Shing) and Mystus vittatus (Tengra) fishes were collected and subjected to form an in vitro biofilm by shaking condition into the wise bath. The drug-resistant pattern was determined by the Kirby Bauer technique. Results All the samples exhibited a huge array (up to 107 cfu/ml or g) of bacteria such as E. coli, Klebsiella spp., Vibrio spp., Salmonella spp., Proteus spp. and Staphylococcus spp. The isolates from both the bulk samples and their corresponding biofilms were subjected to antibiogram assay using antibiotics such as Ampicillin (10 µg), Erythromycin (15 μg), Streptomycin (STP 10 μg), Oxacillin (10 µg), Nalidixic acid (30 µg). Before biofilm formation, few of the isolates were found to be sensitive and few were resistant against the antibiotics. But when the species were isolated from the biofilm the sensitive one acquired drug resistance and resistant strain unveiled more resistance towards the same antibiotics. The present study revealed extensive bacterial contamination in fish samples among those some were resistant against the supplied drugs. Conclusion After the formation of multi-species biofilm, the isolates became more resistant against the same drugs that is alarming for consumers and major obstacles to maintain sustainable health.

This research was to explore antibiotic-induced drug resistance of Salmonella enteritidis and its biofilm formation mechanism. Kirby-Bauer (K-B) disk method recommended by Clinical and Laboratory Standards Institute (CLSI) was used to test drug sensitivity of Salmonella enteritidis to 16 kinds of antibiotics including ß-lactams, aminoglycosides, quinolones, sulfonamides, chloramphenicols, and tetracyclines. Polymerase chain reaction (PCR) was performed to detect carrying of drug resistance genes of 29 kinds of antibiotics including ß-lactams, aminoglycosides, quinolones, sulfonamides, chloramphenicols, and tetracyclines of Salmonella enteritidis. The expressions of esp, ebpA, ge1E, and fsrB genes in biofilm group and plankton group were detected when Salmonella was induced, and difference of gene expression was detected by FQ-PCR. The drug resistance rates of Salmonella enteritidis to nalidixic acid, ampicillin, streptomyces, and cefoperazone were high, which were 94.5%, 75%, 67%, and 52%, respectively. 94 strains of Salmonella enteritidis formed 22 kinds of drug resistance spectrum, the strains were generally resistant to 4-5 antibiotics, and some strains formed fixed drug resistance spectrum as follows: AMP-CFP-STR-NA-TE (22.6,21.7%), AMP-STR-NA-TE (17,16%), and AMP-CFP-STR-NA (11.1,10.6%). During biofilm formation, fsr can increase expression of ge1E and decrease expression of esp and ebpA. Consequently, Salmonella enteritidis was generally resistant to nalidixic acid, ampicillin, and streptomycin, and the multidrug resistance was severe. The drug resistance genes sul2, sul3, blaTEM-1-like, tet(A), and tet(G) were highly carried in Salmonella enteritidis. Esp, ebpA, ge1E, and fsrB genes were closely related to biofilm formation of Salmonella enteritidis., Graphical abstract

The genome of Vibrio cholerae O139 strains has undergone cryptic changes since its first emergence in 1992 in South India. This study aimed to determine the presence of genotypic changes marked in ctxB, tcpA and rstR genes located within the CTX prophages among the strains of V. cholerae O139 isolated from 1999 to 2017 in Odisha. Antibiotic susceptibility test was conducted on 59 V. cholerae O139 strains. A conventional PCR assay was done for ctxB gene typing followed by sequencing along with identification of rstR and tcpA gene. Pulsed-field gel electrophoresis (PFGE) was carried out to reveal clonal variations among the V. cholerae O139 strains. Among V. cholerae O139 isolates more than 60% showed resistance to ampicillin, co-trimoxazole, furazolidone, streptomycin, neomycin and nalidixic acid. The ctxB sequencing and rstR allele-specific PCR assay revealed the presence of three genotypes 1, 3 and 4 with at least one copy of CTX Calc φ in addition to CTX ET and CTX Cl prophages in V. cholerae O139 isolates. PFGE analysis revealed 13 pulsotypes with two clades having 60% similarity among V. cholerae O139 strains. The circulating V. cholerae O139 strains in Odisha showed variation in genotypes with multiple clonal expansions over the years.

Quinolone-based antibiotics commonly detected in surface, ground, and drinking water are difficult to remove and therefore pose a threat as organic contaminants of aqueous environment. We performed adsorptive removal of quinolone antibiotics, nalidixic acid and ofloxacin, using a zirconium-porphyrin-based metal-organic framework (MOF), PCN-224. PCN-224 exhibits the highest adsorption capacities for both nalidixic acid and ofloxacin among those reported for MOFs to date. The accessible metal sites of Zr metal nodes are responsible for efficient adsorptive removal. This study offers a pragmatic approach to design MOFs optimized for adsorptive removal of antibiotics.

Fluoroquinolones (FQs) are synthetic and broad-spectrum antimicrobial drugs derived from nalidixicacid. FQs are used against SARS-CoV-2 in our country, and for the treatment of some urinary tract diseases, gastrointestinal diseases, respiratory tract diseases, sexually transmitted diseases, and dermatological diseases. The present study investigated the effect of 1-,7-,14-day treatments of three differentFQ derivatives; ciprofloxacin (CIP) 80 mg/kg/day, levofloxacin (LVX) 40 mg/kg/day, and moxifloxacin(MXF) 40mg/kg/day, on biochemical parameters, lipid peroxidation, antioxidant enzymes, and immunotoxicity. 72 Wistar albino male rats were distributed to four groups including 18 rats in each group and were sacrificed on three different time points. The 14-day treatment of MXF significantly reduced the levels of aspartate aminotransferase (AST), glucose, reduced glutathione (GSH), malondialdehyde (MDA), catalase (CAT), myeloperoxidase (MPO), adenosine deaminase (ADA), and glutathione peroxidase (GPx). Furthermore, 14-day treatment of LVX increased liver [GSH, MPO, ADA, superoxide dismutase (SOD)], and GSH (erythrocyte) levels; whereas it significantly reduced the levels of AST, TG (triglycerides) and associated parameters levels in all the tissues (MDA), erythrocytes, and liver (MPO, CAT, SOD, GPx). After 14-day treatment of CIP; the erythrocyte levels of GSH, MPO, GPx, and CAT significantly decreased; whereas the levels of glucose, creatinine, MPO (liver), and GST (kidney and erythrocyte) significantly increased. It has been concluded that FQ derivatives used in this experiment did not display any correlation in terms of the efficacies in the different time points and tissues. Thus, it is recommended to use such FQ derivatives considering the duration of use and target tissue.

Background: Salmonella enteric serovars Typhi and Paratyphi are known to cause enteric fever. Multidrug resistance in S. Typhi and S.Paratyphi has emerged as a cause of concern. Aims: To evaluate antimicrobial susceptibility patterns of Salmonella enteric serovar Typhi (S. Typhi) and S.Paratyphi obtained from blood culture. Materials and Methods: All S. enteric isolates obtained from blood cultures of clinically suspected cases of enteric fever coming to microbiology laboratory, Nirmal hospital, from January 2015 to September 2017 were included in the study. Antimicrobial susceptibility patterns were determined using commercial antimicrobial disks chloramphenicol (30 g), nalidixic acid (30 g), ampicillin (10 g), azithromycin (15 g), cotrimoxazole (1.25/23.75 g), ciprofloxacin (5 g), and ceftriaxone (30 g). Antimicrobial susceptibility testing was performed in accordance with the Clinical and Laboratory Standards Institute (CLSI) guidelines of respective year by KirbyBauer disc diffusion method. Result: Total 330 isolates of salmonella are there out of that 298 is Salmonella typhi. 32 are Salmonella para A, while 1 is of Salmonella para B. Enteric fever cases pick month are April, May, June and July. Sensitivity to first line drugs are > 80%, Nalidixic acid resistant Salmonella (NARS) are 79%, while Multi drug resistant (resistant to ampicillin, chloramphenicol and co-trimoxazole all three)Salmonella are 3%. Conclusion: Periodic evaluation of antibiotic susceptibility pattern is necessary to see changing pattern of antibiotics. Evaluation of Nalidixic acid resistant Salmonella and periodic evaluation of multi drug resistant Salmonella is also important as emergence of MDR strain is observed in our study. Keywords: Multi drug resistant, Nalidixic acid resistance, Salmonella typhi, Typhoid

Background: Coagulase Negative Staphylococci (CoNS) are common inhabitants of skin and mucous membrane, may act as pathogens causing fatal infections especially in immunocompromised patients. CoNS mainly cause infections involving biofilm on implanted biomaterials. Increase in antimicrobial resistance causes difficulties to treat life threatening infections. Despite their growing importance, their speciation is rarely done. Therefore, the present study is undertaken to identify CoNS to the species level and to know their antibiotic susceptibility pattern along with rate of MRCoNS. Materials and Methods: 250 isolates from various clinical specimens were considered in this study. The isolates were identified by colony morphology, Gram staining, catalase, slide and tube coagulase test. Speciation was done by Novobiocin resistance, urease activity, ornithine decarboxylase, pyrrolidonylarylamidase and aerobic acid production from mannose. The antimicrobial susceptibility was performed by Kirby-Bauer’s disc diffusion method as per CLSI guidelines. Results: Among 250 CoNS isolates, commonest species identified was S.epidermidis(59.2%) followed by S.haemolyticus(19.6%) and S.saprophyticus(12.4%). They were commonly isolated in the age group 21 to 30 years (26.8%) and among males(58%). Total of 33.2% were isolated from pus followed by blood(21.6%). Majority species expressed resistance towards nalidixic acid(97.2%) followed by Penicillin(94%), 74.4% to Amoxicillin-Clavulanic acid and 66.4% to Cotrimoxazole. All the isolates were sensitive to Vancomycin. Methicillin resistance among CoNS was 73.2%. Conclusion: The increased recognition of pathogenic potential in CoNS and emergence of drug resistance among them demonstrates the need to adopt simple laboratory methods to identify the species and determine the antibiotic resistant patterns to help the clinicians in treating the infections caused by CoNS. Keywords: CoNS, MRCoNS, Speciation, S epidermidis, S hae

Among all nitrogen-containing heterocycles, the 1,8-naphthyridine scaffold has recently gained an immense amount of curiosity from numerous researchers across fields of medicinal chemistry and drug discovery. This new attention can be ascribed to its versatility of synthesis, its reactiveness and the variety of biological activities it has exhibited. Over the past half-decade, numerous diverse biological evaluations have been conducted on 1,8-naphthyridine and its derivatives in a quest to unravel novel pharmacological facets to this scaffold. Its potency to treat neurodegenerative and immunomodulatory disorders, along with its anti-HIV, antidepressant and antioxidant properties, has enticed researchers to look beyond its broad-spectrum activities, providing further scope for exploration. This review is a consolidated update of previous works on 1,8-naphthyridines and their analogs, focusing on the past 5 years.

Zoonotic origin of antibiotic resistant coliform bacteria has become a great threat to human health. Poultry meat is one of the most common sources of protein that has become the source of many antibiotic resistant bacteria. This investigation aimed to identify the prevalence of antibiotic resistant Escherichia coli strains in poultry meat that are being sold in different market places of Guwahati city. Single disc diffusion method was used to screen 98 E. coli isolates for their susceptibility against 11 different antimicrobial agents, namely, ampicillin, imipenem, cefotaxime, cefpodoxime, ceftazidime, cefoxitin, chloramphenicol, amikacin, streptomycin, nalidixic acid and tetracycline. Double disk diffusion test with cefotaxime and ceftazidime (third generation cephalosporin agents) was done to identify ESBL strains among them. All isolates were resistant to a minimum of 2 antimicrobial agents. Eighty two percent were resistant to broad spectrum antibiotics, such as, tetracycline, 80% to nalidixic acid, 76% to ampicillin. Prevalence of multiple antibiotic resistant or multi-drug resistant and ESBL positive isolates was 86% and 33%, respectively. This study has clearly revelled the risk factor associated with consumption or handling of marketed poultry products and also highlighted the matter of excessive administration of antibiotics in poultry farming practice.

A major current problem in public health is the issue of antimicrobial resistance of Escherichia coli in humans and poultry. In Indonesia, multidrug-resistant E. coli are of specific concern since such E. coli may cause public health problems in humans. The prevalence of multidrug-resistant chicken E. coli strains and the E. coli resistance genes, which are tet(A) and tet(B) genes, were investigated in the present study. A total of 57 swabs were collected from layer and broiler breeder farms in West Java, Indonesia, and used in the experiment. Eighteen isolates were identified as E. coli by the disk diffusion method. The isolates classified as drug-resistant and intermediate were then identified using PCR for the antimicrobial resistance genes. The results showed that 18 isolates of E. coli from layer-breeder and broiler-breeder farms in West Java were resistant to ampicillin (100%), nalidixic acid (94%), tetracycline (88%), oxytetracycline (83%), gentamicin (27%), and chloramphenicol (22%). PCR identification of E. coli antimicrobial-resistant genes in 18 isolates showed tet(A) and tet(B) genes. This study reports antimicrobial resistance genes among E. coli on layer and broiler breeder farms in West Java. This present study showed that E. coli isolated from layers-breeder and broiler-breeder farms in West Java of Indonesia carried tet(A) and tet(B) genes, the multidrug-resistance genes.

Campylobacteriosis is among the most frequently reported foodborne zoonoses. A total of 848 samples were screened for Campylobacter spp. and occurrence was found to be 8.7%, 2.3% and 1.65% in broiler cecum samples, chicken meat samples and slaughter house environment swabs, respectively. High level of antimicrobial resistance was found against tetracycline (64.1%), doxycycline (54.4%), ampicillin (46.6%), nalidixic acid (42.7%), kanamycin (35.9%), and ciprofloxacin (33.33%). Resistance to co-amoxiclav (19.4%) and erythromycin (21.4%) was less common. The MAR index of the isolates was in the range of 0.11-0.78. Multi-drug resistance was observed in 54.4% of the isolates, with 53.2% C. jejuni and 55.3% C. coli isolates found resistant against three or more classes of antimicrobials. Presence of mutations in gyrA and 23S rRNA genes was investigated, which revealed that all the fluoroquinolone resistant isolates possessed Thr-86-Ile point mutation, whereas only 68% of erythromycin resistant isolates had A2075G mutation. The tetO gene was present in 91.7% tetracycline resistant isolates and blaOXA-61 gene was detected in 97.9% of the ampicillin resistant isolates. The occurrence of antimicrobial resistant Campylobacter spp. in broiler chicken samples and slaughter house settings is a public health risk and calls for judicial use of antimicrobials.

Background: Tuberculosis (TB) sputum culture contaminants make it difficult to obtain pure TB isolates.We aimed to study and identify persistent TB sputum culture contaminants post the standard laboratory pre-culture sample decontamination techniques. Methods: This was a longitudinal study of TB sputum culture contamination for a cohort of TB patients on standard treatment at: baseline, during TB treatment and post TB treatment. Sputum samples were decontaminated with 1.5%NaOH and neutralized using 6.8 Phosphate buffer solution.Sputum was then inoculated into MGIT (mycobactrial growth indicator tube) supplemented with 0.8ml PANTA. A drop of each positive MGIT culture was sub cultured onto blood agar and incu- bated for 48 hours at 35 -37OC.Any growth was identified using growth characteristics and colony morphology. Results: From October 2017 through May 2019;we collected 8645 sputum samples of which 8624(99.8%) were eligible and inoculated into MGIT where 2444(28.3%)samples were TB culture positive and 255(10.4%)were positive for contam- inants:237 none-tuberculosis bacteria, 12 fungi and 6 mixed(none-tuberculous bacteria+fungi).There was no statistically significant difference between none tuberculosis bacteria and fungi in the treatment (OR=1.4,95%CI:0.26–7.47,p=0.690) and the post treatment TB phases(OR=2.02,95%CI:0.38–10.79,p=0.411)Vs baseline. Conclusion: None-tuberculous bacteria and fungi dominate the plethora of TB sputum culture contamination and persist beyond the standard laboratory pre-culture decontamination algorithm. Keywords: Bacteria; Fungi; Inoculation; PANTA (Polymyxin B; Amphotericin B; Nalidixic acid; Trimethoprim; Azlocillin).

Verotoxin-producing E. coli are getting an emergence for human health and day by day, it is also becoming more alarming in the fact that, they are acquiring multidrug-resistant profiles. This study aimed at isolation and identification of verotoxigenic E. coli followed by the antibiogram of the species from salad vegetables at Jashore district in Bangladesh. A total of 119 raw vegetable salad samples were collected from different areas of the Jashore district. The collected samples were initially enriched in nutrient broth and then used for streak plating on MacConkey and followed by Eosin Methylene Blue (EMB) agar media. Escherichia coli species were isolated and identified following observation of the cultural, microscopic, and biochemical characteristics and further analyzed to determine the presence of verotoxin (VT) producing genes through polymerase chain reaction (PCR) using specific primers (VT1, VT2, and Eae). A panel of antibiotics were tested following the disc diffusion method for determining the antibiotic profile. Total 55 (46.22%) E. coli was isolated phenotypically. 6 (10.9%) isolated E. coli showed positive by amplifying verotoxin-producing gene vt1, but none of the samples were positive vt2 and eaeA gene. Antibiogram for 55 E. coli isolates showed the highest resistance to Erythromycin (83.64%), Streptomycin (78.18%), Ceftriaxone (70.91%). On the other hand, the most heightened susceptibility was observed for Nalidixic acid (76.36%). Moreover, six vt1 positive isolates showed a multidrug-resistant profile. Thus, the presence of toxigenic genes in the isolates suggests the proper maintenance and regular monitoring of raw salad items should be increase to ensure healthy life in this region. Key words: Vegetable salad, Escherichia coli, verotoxin, antimicrobial resistant, polymerase chain reaction (PCR).

Aim This study aimed to investigate the occurrence of antibiotic resistance phenotype and simultaneously understand its genetic basis in Escherichia coli isolated from the cloacal swabs of commercial chickens from north India. Methods and results Escherichia coli isolates were assessed for susceptibility to 14 different antibiotics using the disc-diffusion technique and were screened for the presence of 22 antibiotic resistance genes (ARGs) by employing PCR. Isolates were found to be highly resistant to fluoroquinolones (nalidixic acid 91%, norfloxacin 73% and ciprofloxacin 66%), tetracycline (71%), beta-lactams (ampicillin 49% and amoxicillin/clavulanic acid 37%), co-trimoxazole (48%), streptomycin (31%) and chloramphenicol (28%); and comparatively less resistant to cefazolin (13%), amikacin (10%), aztreonam (4%), gentamicin (4%) and ceftriaxone (3%). Sixty-three percent of isolates were resistant to more than four different drugs. Abundance of plasmid-borne ARGs like tetA (83%), sul3 (44%), aadA1 (44%), strA (43%), strB (41%), qnrS (38%), sul2 (28%) and aac(6)-Ib-cr (15%) was observed among the isolates. Forty-five percent of isolates possessed more than five different ARGs. Quinolone resistance-determining region (QRDR) mutations within gyrA and parC genes were found to be the major determiners of quinolone resistance. QRDR mutations included leu83, asn87 and gly87 within gyrase-A polypeptide and ile80 and lys84 within topoisomerase IV (encoded by parC). Conclusions Our findings suggest the abuse of antibiotics as feed additives and prophylactic drugs in Indian poultry sector. It also projects this industry as an active hotspot for the replication and selection of ARGs. Significance and impact of the study Our findings would provide evidence to the authorities for formulating effective strategies for restricting antibiotic usage as non-therapeutic agents in food animals. Occurrence of both plasmid-borne and chromosome-borne resistance towards quinolones can drive movement of resistance phenotype across bacterial species and vertical movement of resistance along the bacterial generations, respectively, which can pose mitigation challenges.

Edwardsiella tarda is a common fish pathogen, causing significant septicemic diseases in fish. This study was carried out to investigate prevalence of E. tarda among Tilapia zilli at EL manzla lake, Dakahlia governorate and characterize the isolates phenotypically and genotypically in addition to detection of multi-drug resistance genes (B-lactames genes and plasmid-mediated quinolone resistant genes by PCR assay. Therefore, (100) samples of Tilapia zilli collected from different localities. Fish samples were subjected to clinical and post-mortem examination then bacteriological examination from liver, kidney and spleen. The suspected isolates were characterized by cultural and morphological characters, some conventional biochemical tests and API 20E system then by PCR assay. Eighteen % isolates were characterized as E. tarda. Furthermore, detection of antimicrobial resistance genes by PCR, the recovered isolates harbored blaSHV and blaOXA-1 with a prevalence of 50% and 25%, respectively with no detection of aac (6′)-Ib-cr and qepA genes in examined isolates. The results of antibiotics sensitivity showed resistance to Nalidixic acid, Lincomycin, Amoxicillin and Norfloxacin and most of isolate were found to be sensitive to Florfenicol and Neomycin.55.6% of recovered isolates showed resistance to three antibiotic classes and 27.7% of recovered isolates showed resistance to four antibiotic classes and considered as MDR. The emergence of MDR-strains represents a threat-alarm and PCR is very rapid method for identification of E. tarda isolates which may be helpful in control of Edwardsiellosis.

Background Nowadays, dried milk products are highly traded and consumed all over the world, so we aimed in this study to evaluate to what extent whole and skim milk powders are safe and comply with Egyptian standards. Methods Eighty samples of dried milk (50 whole milk powder and 30 skim milk powder) were gathered from several retailers and supermarkets for evaluation of their differing quality and safety parameters. Results The most frequent off-flavors recovered from whole milk powder samples were cooked ones and, in the case of skim milk powder samples, flat ones. Five samples of whole milk powder were of fair quality and three samples of poor quality, according to the sensory evaluation. The compositional parameters, moisture, %, fat, %, protein, %, and acidity, %, were measured as mean values of 3.90 ±0.15, 26.90 ±0.19, 25.53 ±0.27, and 0.99 ±0.03% in the examined whole milk powder samples and 3.77 ±0.08, 1.11 ±0.05, 34.62 ±0.29, and 1.22 ±0.03% in the examined skimmed milk powder samples, respectively. These results were within the range of component requirements set by the Egyptian Standard (2014; ES: 1780/2014) for dried milk products. Also, the microbiological safety of the milk powder samples was analyzed by assessment of the total viable count, total yeast and mold count, Coliforms count, Enterobacteriaceae, E. coli, C. sakazakii, Staphylococcus aureus, Salmonella, and Listeria monocytogenes. Staphylococcus aureus was the most prevalent isolate (36.00% and 6.67%) followed by Enterobacteriaceae (20.00% and 3.33%), of whole and skim milk powder, respectively. Enterobacteriaceae isolates included Enterobacter cloacae ssp. Cloacae, and Pantoea spp., which were specified by traditional biochemical tests and Vitek2 system. All Enterobacteriaceae isolated spp. were resistant to cephalothin, neomycin, tobramycin and colistin sulphate, and sensitive to chloramphenicol, gentamycin and nalidixic acid. E. coli, C. sakazakii, Salmonella, and Listeria monocytogenes couldn't be isolated from all the tested samples. By using Inductive Coupled Plasma - Mass Spectrometer (ICP-MS), we could measure lead and mercury as mean values of 0.243 ±0.069 and 0.261 ±0.052 mg/kg for whole milk powder samples at a percentage of 68.00 and 34.00%, while for the skim milk powder samples they were 0.150 ±0.037, and 0.347 ±0.110 mg/kg at a percentage of 66.67 and 40.00%, respectively. Conclusions Finally, thirty-four whole milk powder and twelve skimmed milk powder samples didn't comply with Egyptian standards, so it is necessary for authorities to put more attention on this and regular monitor it.

The preparation and sale of street foods is booming in African cities in general and especially in N’Djamena. However, the hygienic failures observed during this activity constitute a source of contamination of these foods. The objective of this work is to determine the different serotypes of Salmonella isolated from food sold in the streets of N’Djamena in Chad and to test their sensitivity antibiotics. In total, 447 samples from 12 different types of food were collected and analyzed using standard food microbiology methods. The disk diffusion method was used to test the antibiotic susceptibility of Salmonella strains detected. The serotyping of the 5 strains of Salmonella allowed us to identify 3 serotypes namely Salmonella Mbandaka, Salmonella Idikan and Salmonella Anatum. The susceptibility profiles of the strains to antibiotics were varied. Resistance were observed with the antibiotics Amoxicillin + Clavulanic acid, Cefotaxime and Nalidixic acid. The most active antibiotics were Cefoxitne, Ciprofloxacin, Aztreonam, Imipenem and Choramphenicol with a rate of 100% sensitivity. However, the resistance of these strains to certain antibiotics is a real public health problem that calls out to food safety. Key words: Street food, contamination, Salmonella, serotype, resistance, Chad.

Salmonella is a globally distributed major food-borne pathogen and poultry is one of the predominant sources of salmonellosis in humans. To investigate the presence of motile Salmonella in the poultry hatchery environment, we collected 97 fluff samples from four selected broiler breeder chicken hatcheries from Chattogram, Bangladesh during July-December 2015. To isolate motile Salmonella enterica, we used conventional bacteriological techniques followed by serological verification using anti-Salmonella Poly A-E serum and species confirmation by conventional PCR assay. Antimicrobial susceptibility testing by Kirby-Bauer disc diffusion method for 10 commonly used antibiotics was performed on all isolates. Isolates displaying phenotypic resistance to ampicillin were tested by PCR for blaTEM gene, whereas those resistant to tetracycline were tested for the presence of tetA, tetB and tetC genes. A total of 24 samples (24.7%; 95% CI: 16.5–34.5, N = 97) from 3 hatcheries were positive for motile Salmonella. Of them, 21 (87.5%) and 12 (50.0%) were resistant to ampicillin and tetracycline, respectively, 9 (37.5%) to nalidixic acid and sulphamethoxazole/trimethoprim. No resistance was detected to ceftriaxone, cefoxitin, gentamicin, neomycin, ciprofloxacin and colistin. Ten (42%) of 24 isolates from 2 hatcheries were multi-drug resistant (i.e. resistant to ≥ 3 antimicrobial classes). Six of 21 ampicillin resistant isolates contained blaTEM gene and 10 of 12 tetracycline resistant isolates contained tetA gene. This study highlights the circulation of multi-drug resistant motile Salmonella in the hatchery environment for the first time in Bangladesh. Further epidemiological and molecular studies are therefore needed to identify the serotypes and source of the bacteria in hatcheries.

Los genes de resistencia a los antibióticos (ARG) han sido descritos principalmente en bacterias; sin embargo, en fagos atemperados los estudios han sido escasos. En este estudio se determinó la prevalencia de los genes qnrB, qnrA y blaTEM en cepas de Escherichia coli y en fagos atemperados obtenidos por inducción del ciclo lítico en dichos aislamientos. Se recolectaron 48 muestras de agua potable, agua residual y alcantarillado en rastros del Estado de México obteniendo 37 aislamientos de E. coli. La mayor resistencia fue para tetraciclina 32/37 (86.4 %), seguido de trimetoprim-sulfametoxasol 19/37 (51.3 %) y por último ampicilina y ácido nalidíxico con el mismo número de aislamientos 18/37 (48.6 %). La prevalencia del gen blaTEM en aislamientos bacterianos fue 37.8 %, mientras que en los aislamientos fágicos fue 3.5 %. Los genes qnrA y qnrB fueron encontrado s en 8.1 % y 29.7 % respectivamente en aislamientos bacterianos, mientras que en los aislamientos fágicos fueron obtenidos 2.7 y 24.3 % respectivamente. Los resultados muestran que los ARG presentes en aislamientos bacterianos se relacionan en el ADN fágico, lo que indica el papel significativo en la propagación de ARG en los rastros estudiados. Comprender los mecanismos de resistencia a antimicrobianos, permitirá establecer medidas efectivas para disminuir este fenómeno.

Homemade foods have been reported as an important contributor to some foodborne outbreaks. This study determined the prevalence and number of Salmonella spp. on selected pathways of fried chicken preparation and cooking at the household level and investigated their antimicrobial resistance. Salmonella serovar was confirmed by polymerase chain reaction (PCR) and partial sequencing using primer 785F and 907R. Samples consisted of chicken meat (raw, pre-cooked and fried), seasoning, water, mortar, and the hands of the food handler. The results showed that Salmonella spp. was found in 22.1% of 104 samples. The level of Salmonella found was in the range of 0.3 MPN/g (in fried chicken and water) to 920 MPN/g (in marinated raw chicken). Six Salmonella serovars were identified, namely S. Typhimurium, S. Bergen, S. Enteritidis strain FORC_052, S. Enteritidis strain GD1011, S. Typhi strain 541, and S. Typhi strain 3N4. Three were resistant to nalidixic acid, while one was resistant to streptomycin.

This research investigates the transferability of plasmid-mediated quinolone resistance (PMQR) genes among enteric bacteria isolates in human and animal samples, as well as its implication on resistance of recipient cells. A total of 1,964 strains of five different enteric bacteria species (Escherichia coli, Salmonella sp., Shigella sp., Klebsiella sp. and Aeromonas sp.) were screened for plasmid-mediated quinolone resistance (PMQR) genes from a population of quinolone resistant (Q-r) isolates. Screening for PMQR isolates was achieved by plasmid curing using sub-lethal concentration of Sodium Dodecyl Sulphate and PMQR genes (qnrA, qnrB, qnrS, Aac(6′)-Ib-crand Qep A) were detected by polymerase chain reaction (PCR). Conjugation and transformation experiments were attempted to ascertain transfer of genes from the Q-r isolates to a susceptible, standard recipient, E. coli J53-2. The minimum inhibitory concentration (MIC) was determined before and after gene transfer, using E-test strips. Results indicate that percentage resistance to the quinolones (Qs): Nalidixic acid, Ciprofloxacin, Pefloxacin and Ofloxacin determined by agar plate diffusion technique stood at 52.6, 47.3, 50.5, 70.6 and 46.0% for Escherichia coli, Salmonella sp., Shigellasp., Klebsiella sp. and Aeromonas sp. respectively. Analysis of variance indicated the occurrence of significant differences (F, 46.77–613.30; 0.00) in the resistance to each tested Qs. Generally, Human isolates showed greater resistance than Animal isolates (57.4 vs 47.2%). Investigation with specific primers indicated 11, 15, 7, 1 and 0 for qnrA, qnrB, qnrS, qepA and Aac(6′)-Ib-cr genes respectively, out of 1018 Q-r and 29 PMQR isolates. Gene transfer experiments indicated the transfer of all genes except qepA either by conjugation or transformation. The MIC of tested Qs on recipient bacterium before gene transfer greatly increased from 0.0625 to 0.25 µg/mL, after transfer. This study demonstrates that PMQR genes amongst enteric bacteria in the Niger delta of Nigeria were transferable and transfer conferred a higher Q- resistance on recipient bacterium.

Objective: This work investigated the antimicrobial resistance (AMR) and virulence of Escherichia coli and Staphylococcus aureus in communally consumed cheeses in Egypt. Materials and Methods: This study examined 100 samples of Domiati, Tallaga, Cheddar, and Ras cheese collected from several shops and supermarkets. Samples were spread on selective media to isolate bacterial strains. Molecular characterization of bacterial isolates was carried out using polymerase chain reaction to determine Shiga toxin 1 (stx1), Shiga toxin 2 (stx2), eaeA, and nuc genes. The isolates were tested for susceptibility to 14 antibiotics by disk diffusion assay. Results: In this study, several E. coli serotypes were identified. E. coli O26:H11, O103:H2, and O111:H2 expressed stx1/2, E. coli O114:H4 expressed stx1, E. coli O17:H18, O21:H7 and O146:H21 expressed stx2, while only E. coli O26:H11 and O111:H2 expressed eaeA. The E. coli isolates were resistant to at least one antibiotic, while most isolates (82.4%) showed multidrug resistance (MDR). AMR to erythromycin was the highest (100%), followed by nalidixic acid (94.1%), cefotax¬ime (82.4%), vancomycin and cephalothin (64.7%), penicillin G (52.9%), sulfamethoxazole (47.1%), amikacin and kanamycin (35.3%), ampicillin (29.4%), tetracycline and ciprofloxacin (23.5%), and doxycycline (11.8%), while gentamicin showed the least resistance (5.9%). The multiple antibi¬otic resistance (MAR) index of the isolated E. coli ranged from 0.071 to 1 (mean = 0.478). All S. aureus isolates expressed the nuc gene and demonstrated resistance to at least one antibiotic, and 90% of isolates were MDR. AMR to kanamycin and cephalothin was the highest (100%), fol¬lowed by penicillin (90%), doxycycline (70%), nalidixic acid and sulfamethoxazole (60%), erythro¬mycin (50%), tetracycline, cefotaxime, and gentamicin (40%), ciprofloxacin and ampicillin (30%), and amikacin (20%). In comparison, vancomycin showed the least resistance (10%). MAR index of isolated S. aureus ranged from 0.143 to 1 (mean = 0.529). Conclusion: The antimicrobial-resistant E. coli and S. aureus are potential risks for public health and may have a role in disseminating AMR to other pathogenic and non-pathogenic microbes. [J Adv Vet Anim Res 2021; 8(2.000): 246-255]

Salmonella enterica serotype Kentucky (S. Kentucky) is an important Salmonella serotype with multiple sequence types (ST) with a worldwide incidence. We identified 8 STs from 180 strains of S. Kentucky, and ST314 emerged as the most commonly encountered ST. Drug susceptibility testing revealed that ST314 had multiple resistance properties, and 75.5% of the strains were resistant to three or more classes of antimicrobials. The rate of resistance to chloramphenicol, florfenicol, sulfafurazole and tetracycline were greater than 60%. The rates of ST314 resistance to quinolones were as follows: ciprofloxacin, 32.1%; nalidixic acid, 16%; and ofloxacin, 7.5%. Investigating the mechanism of quinolone resistance of ST314 revealed that mutations in the quinolone resistance-determining regions were rare, and resistance mainly occurred due to the resistance genes carried by plasmids. Only 1.9% (2/106) of ST314 strains had mutations in the quinolone resistance-determining regions (QRDR). The drug resistance genes of ST314 were primarily of plasmid-mediated quinolone resistance (PMQR). The detection rate of Salmonella genomic island 1 (SGI1) in ST314 was 12.3%. XbaI-pulsed-field gel electrophoresis revealed that S. enterica Kentucky ST314 was capable of cross-regional and cross-host transmission in China. We found ST314 to be the dominant S. Kentucky ST in China, and it carried multidrug resistance. This is the first report about the emergence of quinolone-resistant S. enterica Kentucky ST314 in China, which is different from previous reports, and the findings of the present study suggest that the mechanism of quinolone resistance in these strains are plasmid-mediated. Notably, plasmids carrying resistance genes may promote the rapid spread of ciprofloxacin resistance.

Salmonella spp. causes foodborne diseases related to the consumption of contaminated foods, especially poultry products. This study aimed to investigate the occurrence of Salmonella spp. serovars in raw eggs from supermarkets and street food markets in southern Brazil, to analyze virulence genes, resistance profiling to antimicrobials and sanitizers, and to determine the susceptibility of the isolates to Butia odorata extract. Among 160 samples analyzed, just two (1.25%) were positive for Salmonella spp.. One positive sample was from egg yolk (S. enterica serovar Gallinarum, isolate S28), and another one was from eggshell (S. enterica serovar Panama, isolate S37). Regarding the virulence genes, the isolate S37 harbored all the genes evaluated (hilA, invA, spvC, sefA, and pefA), while the isolate S28 did not harbor the pefA gene. The isolate S28 was resistant to tobramycin, azithromycin, and trimethoprim, while the isolate S37 showed resistance profile just to nalidixic acid. However, none of the resistance genes evaluated were identified. Both isolates showed resistance to benzalkonium chloride, chlorhexidine digluconate, sodium hypochlorite, and peracetic acid, presenting high MIC values for these sanitizers. In contrast, B. odorata extract showed antimicrobial activity against the isolates S28 and S37, however, more studies are needed to prove its potential as a natural antimicrobial compound. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13197-021-05113-5) contains supplementary material, which is available to authorized users.

In this study, we investigated the prevalence, serovar distribution, and antimicrobial resistance pattern of Salmonella isolates from vegetable, fruit, and water samples in Ho Chi Minh City, Vietnam. Salmonella was detected in 75% (30/40), 57.1% (12/21), 17.5% (28/160), and 2.5% (1/40) of river water, irrigation water, vegetable, and ice water samples, respectively. However, no Salmonella was isolated from 160 fruit and 40 tap water samples examined. A total of 102 isolates obtained from 71 samples belonged to 34 different serovars, of which Salmonella Rissen was the most prevalent, followed by Salmonella London, Salmonella Hvittingfoss, and Salmonella Weltevreden. Certain Salmonella serovars such as Newport, Rissen, and Weltevreden were isolated from both vegetable and water samples. Antimicrobial resistance was most commonly observed against tetracycline (35.3%), followed by chloramphenicol (34.3%), ampicillin (31.4%), trimethoprim/sulfamethoxazole (23.5%), and nalidixic acid (10.8%). Of 102 isolates analyzed, 52 (51%) showed resistance to at least 1 antimicrobial class whereas 27 (26.5%) showed multidrug resistant (MDR) phenotype, being resistant to at least three different classes of antimicrobials. Determination of the presence and type of β-lactamase genes showed the cooccurrence of blaTEM-1 and blaCMY-2 in one Salmonella Agona isolate from a river water sample. Taken together, these data indicated that both environmental water and vegetables were contaminated with Salmonella, including MDR strains, and that environmental water used in irrigation might have been the source of Salmonella contamination in the vegetables.

Our study aimed to determine the prevalence of Campylobacter jejuni isolated from raw milk, cheese, and human stool samples in Beni-Suef Governorate, Egypt, and to characterize the antibiotic resistance profile and virulence genes of the isolates. An additional objective was to evaluate the effectiveness of cinnamon oil and Lactobacillus acidophilus La5 for controlling C. jejuni in cheese. A total of 200 samples of raw milk and dairy products, including 50 samples of raw milk and 150 samples of three different types of cheese were used. Fifty-three human stool samples were also collected. The samples were tested for the presence of C. jejuni using culture and molecular methods. Campylobacter spp. were isolated from 9.5% (19/200) of the raw milk and cheese samples. The highest prevalence was observed in milk samples (18%), followed by Kareish cheese (14%) and Talaga cheese (6%). In contrast, C. jejuni was not found in any of the Feta cheese samples. Of the human stool samples, 21 (39.6%) were positive for C. jejuni. Of the isolates, 60-90% were highly resistant to the antimicrobial agents tested, that is, nalidixic acid, ciprofloxacin, and tetracycline. Virulent cadF and cdtA genes were detected in all isolates. As milk and dairy products are important sources of contamination, reducing the level of C. jejuni in them will lower the risk to consumers. We showed that L. acidophilus La5 was able to control C. jejuni in Kareish cheese, but cinnamon oil was less effective.

Introduction: With increasing fluoroquinolone resistance, extended spectrum cephalosporins are recommended for the treatment of invasive Salmonella infections. However, Extended spectrum beta-lactamases (ESBL) producing Salmonella Paratyphi A causing enteric fever is on the rise and constitutes a major therapeutic challenge. Hence, we aimed to assess the incidence of ESBL production, fluoroquinolone resistance in S. Paratyphi A and to compare the fluoroquinolone resistance detection methods. Methodology: Seventeen blood-culture isolates of S. Paratyphi A were tested for susceptibility to ampicillin, chloramphenicol, co-trimoxazole, streptomycin and tetracycline (ACCuST), fluoroquinolones, azithromycin and ceftriaxone by disk diffusion method. We compared and correlated between disk diffusion of ciprofloxacin and pefloxacin with ciprofloxacin MIC. Combined disk test was employed to determine ESBL production. Results: In this study, 13(76.5%) isolates were nalidixic acid resistant (NAR), 16 (94.1%) were pefloxacin resistant, while 7 (41.2%), 9 (52.9%) exhibited resistance and intermediate susceptibility to ciprofloxacin respectively. The MIC50, MIC90 of ciprofloxacin was 1 µg/mL, 2 µg/mL respectively. Among the NAR, 76.92% were DSC (MIC 0.5-1 µg/mL) and 23.08% had an MIC of 2-4 µg/mL. Of note, 4 isolates with DSC were NAS. Of the 17 S. Paratyphi A isolates, 14 (82.4%) were ESBL producers and 11 (64.7%) isolates were ceftriaxone susceptible. Conclusions: Multidrug resistant (AmpRChlRSxtR) S. Paratyphi A with combined resistance to fluoroquinolones and ESBL production is a cause of concern. We found S. Paratyphi A isolates with a relatively unusual phenotype: nalidixic acid susceptible but exhibited DSC; pefloxacin susceptible but ciprofloxacin resistant. Of note one multidrug resistant (AmpRChlRSxtR) isolate, an ESBL producer exhibited resistance to azithromycin, cephalosporins and fluoroquinolones but was susceptible to carbapenems and streptomycin.

In this work, the occurrence of 34 common antibiotic (15 sulfonamides and 19 quinolones) residues were evaluated in 236 ready-to-eat duck eggs (salted and preserved duck eggs) marketed through e-commerce stores by ultra-performance liquid chromatography coupled to tandem mass spectrometry, and subsequent dietary risk assessments for Chinese consumers were conducted. Among violated positives in duck egg samples, 11 analytes were found including sulfamethazine, sulfaquinoxaline, sulfamethoxazole, sulfadiazine, sulfamonomethoxine, ciprofloxacin, enrofloxacin, ofloxacin, flumequine, sarafloxacin, and nalidixic acid. A higher number of antibiotics were detected in salted duck eggs (five sulfonamides and six quinolones) than in preserved duck eggs (one sulfonamide and two quinolones). The maximum contamination of sulfonamides and quniolones was 448.0 µg/kg (sulfaquinoxaline) and 563.7 µg/kg (enrofloxacin) in salted duck eggs, respectively. Dietary exposure was evaluated through the estimated daily intake (EDI) of risky antibiotics (sulfamethazine, ciprofloxacin, and enrofloxacin) and hazard quotients (HQs). The results showed that EDIs and HQs were in the range of 0.0004 to 0.0099 µg/kg bw/day and 0.0009 to 0.1594%, respectively. The risk was low since HQs obtained were less than 100%. However, a special attention should be paid to ready-to-eat duck egg products high percentile consumers with the prosperity of e-commerce market in China. PRACTICAL APPLICATION: The present analytical method could be used for multiresidue determination of antibiotics in ready-to-eat duck eggs, and dietary risk assessments of risky antibiotics provided a support for the work of regulatory bodies to conduct surveillance programs regarding food safety evaluation of ready-to-eat foods.

Aim: Multidrug resistance (MDR) is a major public health problem worldwide. The aim of this study was to assess the prevalence, levels of antimicrobial susceptibility and extended-spectrum beta lactamase (ESBL) production by Escherichia coli O157: H7. Methodology: A cross sectional study was performed and a total of 116 stool samples were collected from children aged ≤ 5 years presenting diarrhoea from hospital located at district Khairpur. E. coli O157: H7 was isolated on Sorbitol MacConkey agar and isolates were initially characterized by Gram staining. Subsequently biochemical characteristics except oxidase test (which was performed manually) and drug sensitivity test was performed by using Automated MicroScan® walkaway machine. ESBL production by isolates was determined by disc diffusion method as per Clinical & Laboratory Standards Institute (CLSI) guidelines. Results: Out of 116 diarrheal samples tested, 16 (13.79%) samples were positive for E. coli O157:H7. High number of E. coli O157: H7 were isolated from children aged up to 1 year followed by 2-3 years aged. Isolates were frequently found in summer season (12 times) followed by winter (3 times) and Autumn (1 time). The isolates were found 100% resistant against Nalidixic acid, Imipenem, Amoxycillin /Clavulanic Acid, Norfloxacin, Chloramphenicol, Vancomycin, Doxycycline, and Ampicillin and 90% resistant to Cifixime. ESBL production was noted in 12 (75%) out of 16 E. coli O157:H7 isolates as confirmed by CLSI protocol. Conclusion: This study revealed that E. coli O157: H7 should be considered as major pathogenic bacterium causing diarrhea in children less than three years. The prevalence of ESBL producer MDR E. coli O157: H7 is of great concern, which requires monitoring of infection control measures through efficient antimicrobial management to ensure an uncompromised public health.

Introduction: Enteric fever, a systemic infection caused by Salmonella enterica Typhi and S. enterica Paratyphi is one of the most common infections in developing countries such as Nepal. Aside from irrational practices of antibiotic use, mutations in chromosomal genes encoding DNA gyrase and Topoisomerase IV and by plasmid mediated quinolone resistant (PMQR) genes are suggested mechanisms for the development of resistance to nalidixic acid and reduced susceptibility to ciprofloxacin. Regardless of high endemicity of enteric fever in Nepal, there is paucity of studies on prevalence and drug-resistance of the pathogen. Therefore, this study aimed to assess the antibiotic susceptibility pattern of Salmonella isolates and determine the minimum inhibitory concentration of ciprofloxacin. Methods: A total of 1298 blood samples were obtained from patients with suspected enteric fever, attending Sukraraj Tropical and Infectious Disease Hospital (STIDH) during March–August, 2019. Blood samples were inoculated immediately into BACTEC culture bottles and further processed for isolation and identification of Salmonella Typhi and S. Paratyphi. Axenic cultures of the isolates were further subjected to antimicrobial susceptibility testing (AST) by using the modified Kirby–Bauer disc diffusion method based on the guidelines by CLSI. The minimum inhibitory concentration (MIC) of ciprofloxacin was determined by agar-dilution method. Results: Out of 1298 blood cultures, 40 (3.1%) were positive for Salmonella spp. among which 29 (72.5%) isolates were S. Typhi and 11 (27.5%) isolates were S. Paratyphi A. In AST, 12.5% (5/40), 15% (6/40) and 20% (8/40) of the Salmonella isolates were susceptible to nalidixic acid, ofloxacin and levofloxacin, respectively, whereas none of the isolates were susceptible to ciprofloxacin. The MIC value for ciprofloxacin ranged from 0.06-16 µg/mL in which, respectively, 5% (2/40) and 52.5% (21/40) of the isolates were susceptible and resistant to ciprofloxacin. None of the isolates showed multidrug-resistance (MDR) in this study. Conclusion: This study showed high prevalence of quinolone-resistant Salmonella spp., while there was marked re-emergence of susceptibilities to traditional first option drugs. Hence, conventional first-line-drugs and third-generation cephalosporins may find potential usage as the empirical drugs for enteric fever. Although our reporting was free of MDR strains, extensive surveillance, augmentation of diagnostic facilities and treatment protocol aided by AST report are recommended for addressing the escalating drug-resistance in the country.

Carbapenem-resistant Enterobacteriaceae strains have been responsible for an increasing number of hospital-acquired infections globally. This study aimed to determine the prevalence of carbapenemase-producing Enterobacteriaceae and their frequency of antimicrobial-resistant patterns among hospitalized patients across three Khartoum State Teaching Hospitals, Sudan. Materials and Methods. A cross-sectional study was conducted at Khartoum State Teaching Hospitals from April 2018 to October 2019. A total of 384 non-duplicative Enterobacteriaceae strains were isolated from1062 clinical samples obtained from hospitalized patients receiving treatment across three main teaching hospitals. The samples were cultured into a MacConkey agar plate. The Enterobacteriaceae strains were differentiated by specific colony color and again by biochemical test. Antimicrobial susceptibility testing was performed by the disc diffusion method. The minimum inhibitory concentration (MIC) of imipenem and meropenem was performed by the agar dilution method. Multiplex polymerase chain reaction (PCR) was performed to investigate the presence of carbapenemase-encoding genes. Data analysis was carried out using SPSS version 21. Results. Of the 36.2% (384/10.62) nonduplicate of Enterobacteriaceae strains isolated from clinical samples, 122 (31.8%) were carbapenemase-producing Enterobacteriaceae (CPE). Of these isolates, 37 (30.3%) harbored the blaIMP followed by; 29 (23.8%) blaNDM, 21 (17.2%) blaOXA-48, 6 (4.9%) blaGES, 5 (4.1%) were blaKPC, 3(2.5%) blaGIM-1, 2(1.6%) blaVIM and 1 (0.8%) blaSIM-1, while the remaining 19(15.6%) isolates carried combinations carbapenemase blagenes. The most predominant CPE strains were Escherichia coli 40 (32.8%) followed by Klebsiella pneumoniae 24 (19.7%) and Enterobacter aerogenes 14(11.5%). Most of the CPE isolates were isolated from wound swab 40(32.8), sputum 33(27.0), and urine 22(18.0) samples. Furthermost strains showed high resistance rates (>70%) to the antibiotics tested. Resistance to amikacin, tetracycline, co-trimoxazole, and nalidixic acid was 36.9%, 43.4%, 62.3%, and 63.9%, respectively and 82.8 % of CPE strains were susceptible to colistin. The detection of blagenes carbapenemases in CPE strains had a significant effect on both imipenem and meropenem MICs. Conclusion. The most prevalent carbapenemase-producing blagenes among clinical Enterobacteriaceae clinical isolates from the three Khartoum state regions were blaIMP, blaNDM, and blaOXA-48. In contrast, the propensity of the multidrug-resistant profile that has been associated with producing carbapenemase blagenes is alarming. Therefore, it is very important to establish a routine screening of carbapenemase-producing blagenes in clinical isolates to prevent the dissemination of resistant strains among both inpatients and outpatients in hospital settings.

Endrias Zewdu Gebremedhin,1 Gadisa Hirpa,2 Bizunesh Mideksa Borana,1 Edilu Jorga Sarba,1 Lencho Megersa Marami,3 Kebede Abdisa Kelbesa,1 Nega Desalegn Tadese,3 Hirut Abebe Ambecha3 1Department of Veterinary Sciences, College of Agriculture and Veterinary Science, Ambo University, Ambo, Ethiopia; 2Department of Biology, Ambo Preparatory School, Ambo, Ethiopia; 3Department of Veterinary Laboratory Technology, College of Agriculture and Veterinary Science, Ambo University, Ambo, EthiopiaCorrespondence: Endrias Zewdu GebremedhinAmbo University, P.O. Box 19, Ambo, EthiopiaTel +251 911894802Fax +251 112609503Email endrias.zewdu@gmail.comPurpose: Listeriosis is one of the globally distributed foodborne diseases with the highest fatality rate. The objectives of this study were to isolate and identify Listeria species, assess factors for contamination of beef, and antibiogram of Listeria monocytogenes in Ambo and Holeta towns, Central Ethiopia.Materials and Methods: A total of 450 meat samples were collected from abattoirs (n=150), butchers (n=150), and restaurants (n=150) for isolation and identification of Listeria species. Logistic regression analysis was used to assess the association between the occurrence of Listeria species in meat and potential risk factors. The antimicrobial susceptibility test was done using the Kirby Bauer test.Results: The overall occurrence of Listeria species in Ambo and Holeta towns was 28.4% (128/450; 95% confidence interval [CI]: 24.3– 32.9%). The isolation rate of Listeria monocytogenes was 4.4%, Listeria ivanovii 2.2%, Listeria seeligeri 1.8%, Listeria welshimeri 3.8%, Listeria innocua 6.2%, and Listeria grayi 10.2%. The probability of contamination of meat in butchers and restaurants was higher in Holeta than Ambo [OR=3.4; 95%; p=0.001], in dry than wet season [OR=5.2; p=0.009], and where the hygiene of cutting boards was poor (OR=7.7; p=0.008). Of the 20 Listeria monocytogenes isolates, 80%, 70%, 60%, and 55% were resistant to oxacillin, amikacin, and nalidixic acid, chloramphenicol, and tetracycline, respectively. The Listeria monocytogenes isolates were 95%, 90%, and 85% susceptible to amoxicillin, vancomycin, and clindamycin, respectively. About 95% of Listeria monocytogenes isolates were multidrug-resistant. One isolate (5%) had developed resistance to 10 classes of antimicrobial drugs.Conclusion: Listeria species are widespread and study towns, season, and hygiene of cutting boards are independent predictors of isolation of Listeria species. Multidrug resistance among Listeria monocytogenes was very high. Therefore, adequate cooking of meat, regular training of beef handlers, prudent use of drugs, and further molecular studies on Listeria species are important.Keywords: antimicrobial susceptibility, beef, Listeria species, Listeria monocytogenes, multidrug resistance, risk factors, Ethiopia

Background: This study aimed to characterize bla 𝐶𝑇𝑋 - 𝑀 , bla 𝑇𝐸𝑀 , and bla 𝑆𝐻𝑉 genes among extended-spectrum beta-lactamases (ESBLs)-producing Enterobacteriaceae species in different regions of Sudan. Methods: In this cross-sectional study, different clinical samples (n = 985) were collected randomly from symptomatic patients from four geographical regions of Sudan and cultured on chromogenic media. Following bacterial identification, phenotypic screening of ESBLs was done according to CLSI guidelines using cefotaxime (30 μg), ceftazidime (30 μg), and cefepime (30 μg) discs with and without clavulanic acid. The DNA was extracted by guanidine hydrochloride protocol, and then conventional PCR was used to detect bla 𝐶𝑇𝑋 - 𝑀 , bla 𝑇𝐸𝑀 , and bla 𝑆𝐻𝑉 genes. The presence of genes' subtypes was characterized by DNA Sanger sequencing for selected samples. Results: Enterobacteriaceae represented 31% (305/985) of all isolates, 42 (128/305) of which were ESBLs producer, confirmed by phenotypic confirmatory test (75% [96/128] of them were positive for bla 𝐶𝑇𝑋 - 𝑀 genes, 61% [78/128] for bla 𝑇𝐸𝑀 genes, and 38% [48/128] for bla 𝑆𝐻𝑉 genes). Fourteen isolates (11%) were negative for all genes. Forty-eight percent (63/75) of Escherichia coli isolates were positive for bla 𝐶𝑇𝑋 - 𝑀 , while in Klebsiella pneumoniae, the dominant gene was bla 𝑇𝐸𝑀 (82%) and had a low amount of bla 𝑆𝐻𝑉 (59%). There was a significant association (P-value = 0.001 for all except for chloramphenicol, P = 0.014, and amikacin, P = 0.017) between resistance to third-generation cephalosporins and ciprofloxacin, nalidixic acid, meropenem, chloramphenicol, and amikacin. Forty-two percent (40/96) of CTX-M-positive isolates were in Gizera State, 33% (32.96) in Sinnar, 24% (23/96) in Khartoum, and 1% (1/96) in White Nile. Conclusion: We conclude that bla 𝐶𝑇𝑋 - 𝑀 genes are the most dominant genes in ESBLs-producing isolates and are more prevalent in big cities than in rural areas.

El presente reporte es la descripción original de blaTEM-176. Se caracterizaron los mecanismos de resistencia a antimicrobianos de un aislamiento de Escherichia coli enterotoxigénica, determinándose la resistencia a 22 antimicrobianos categorizados en 15 grupos diferentes mediante difusión en agar, estableciéndose grupo filogenético, mecanismos de resistencia y presencia de integrones de Clase 1 y 2 mediante PCR. Integrones y genes de resistencia a β-lactámicos fueron secuenciados. El aislamiento del grupo filogenético A, mostró resistencia o sensibilidad disminuida a ampicilina, amoxicilina más ácido clavulánico, ácido nalidíxico, ciprofloxacino, estreptomicina, kanamicina, tetraciclina, trimetoprim, sulfisoxazol, cotrimoxazol, azitromicina y nitrofurantoina, detectándose la presencia de blaTEM, aadA1/2, aphA1, sul3, tet(A) y un integron de Clase 2 conteniendo un gen dfrA1. La resistencia a quinolonas se relacionó con la substitución Ser83Ala. La secuencia de TEM mostró la substitución Ala222Val, la cual a la fecha no había sido descrita, reportándose como una nueva β-lactamasa, con el nombre de blaTEM-176.

Objective: This study aimed to isolate and identify Escherichia coli from broiler samples from Sukabumi, Indonesia. Also, antibiogram studies of the isolated bacteria were carried out consid¬ering the detection of the antibiotic resistance genes. Materials and Methods: Cloaca swabs (n = 45) were collected from broilers in Sukabumi, Indonesia. Isolation and identification of E. coli were carried out according to standard bacterio¬logical techniques and biochemical tests, followed by confirmation of the polymerase chain reac¬tion targeting the uspA gene. Antibiotic sensitivity test, using several antibiotics [tetracycline (TE), oxytetracycline (OT), ampicillin (AMP), gentamicin (CN), nalidixic acid (NA), ciprofloxacin (CIP), enrofloxacin (ENR), chloramphenicol, and erythromycin] was carried out following the Kirby Bauer disk diffusion method. Detection of antibiotic resistance coding genes was carried out by PCR using specific oligonucleotide primers. Statistical analysis was carried out with one-way anal¬ysis of variance. Results: The results showed that 55.6% (25/45) of the samples were associated with the pres¬ence of E. coli. Antibiotic sensitivity test showed that the E. coli isolates were resistant to TE (88%; 22/25), OT (88%; 22/25), AMP (100%; 25/25), CN (64%; 16/25), NA (100%; 22/25), CIP (88%; 22/25), ENR (72%; 18/25), chloramphenicol (0%; 0/25), and erythromycin (92%; 23/25). On the other hand, the antibiotic resistance coding genes were tetA (86.4%; 19/22), blaTEM (100%; 25/25), aac(3)-IV (0%; 0/16), gyrA (100%; 25/25), and ermB (13%; 3/23). It was found that chlor¬amphenicol is markedly different from other antibiotic treatment groups. Conclusion: Escherichia coli was successfully isolated from cloacal swabs of broiler in Sukabumi, Indonesia. The bacteria were resistant to TE, OT, AMP, CN, NA, CIP, ENR, and erythromycin. Chloramphenicol was more sensitive and effective than other antibiotics in inhibiting the growth of E. coli. The antibiotic resistance genes detected were tetA, blaTEM, gyrA, and ermB. [J Adv Vet Anim Res 2021; 8(1.000): 84-90]

The present report is the original description of bla TEM-176. The mechanisms of resistance to antimicrobial agents were determined in an enterotoxigenic Escherichia coli, determining the susceptibility to 22 antimicrobials classified in 15 different groups by agar diffusion and establishing the phylogenetic group, mechanisms of resistance and presence of Class 1 and 2 integrons. Integrons and β-lactam resistance genes were sequenced. The isolate, belonging to phylogenetic group A, showed the presence of resistance or diminished susceptibility to a ampicillin, amoxicillin plus clavulanic acid, nalidíxic acid, ciprofloxacin, streptomycin, kanamycin, tetracycline, trimethoprim, sulfisoxazole, cotrimoxazole, azithromycin and nitrofurantoin, carrying bla TEM, aadA1/2, aphA1, sul3, tet(A) and a Class 2 integron containing a dfrA1 gene. Quinolone resistance was related to the substitution Ser83Ala. The TEM sequencing showed the presence of the new substitution Ala222Val, which led to the description of the new β-lactamase bla TEM-176.El presente reporte es la descripción original de bla TEM-176. Se caracterizaron los mecanismos de resistencia a antimicrobianos de un aislamiento de Escherichia coli enterotoxigénica, determinándose la resistencia a 22 antimicrobianos categorizados en 15 grupos diferentes mediante difusión en agar, estableciéndose grupo filogenético, mecanismos de resistencia y presencia de integrones de Clase 1 y 2 mediante PCR. Integrones y genes de resistencia a β-lactámicos fueron secuenciados. El aislamiento del grupo filogenético A, mostró resistencia o sensibilidad disminuida a ampicilina, amoxicilina más ácido clavulánico, ácido nalidíxico, ciprofloxacino, estreptomicina, kanamicina, tetraciclina, trimetoprim, sulfisoxazol, cotrimoxazol, azitromicina y nitrofurantoina, detectándose la presencia de bla TEM, aadA1/2, aphA1, sul3, tet(A) y un integron de Clase 2 conteniendo un gen dfrA1. La resistencia a quinolonas se relacionó con la substitución Ser83Ala. La secuencia de TEM mostró la substitución Ala222Val, la cual a la fecha no había sido descrita, reportándose como una nueva β-lactamasa, con el nombre de bla TEM-176.

Objective: The study was carried out for molecular characterization and antibiotic resistance anal¬ysis of Escherichia coli isolated from different turkey farms in Dinajpur, Bangladesh. Materials and methods: A total of 45 samples comprising feces (n = 23) and cloacal swabs (n = 22) were collected randomly from turkeys. The samples were subjected to isolation and identification of E. coli by cultural and biochemical characteristics, followed by polymerase chain reaction and sequencing. An antibiogram of the isolated E. coli isolates was carried out by following the Kirby Bauer disk diffusion method. Results: Out of the 45 samples, 28 (62.21%) were positive for E. coli, of which 16 (35.55%) fecal samples were positive and 12 (26.66%) cloacal swabs were positive. The antibiotic sensitivity analysis revealed that all the E. coli isolates were 100% sensitive to levofloxacin, norfloxacin, neo¬mycin, gentamicin, and nitrofurantoin. On the other hand, all the isolates were 100% resistant to amoxicillin, azithromycin, erythromycin, tetracycline, bacitracin, cephalexin, nalidixic acid, van¬comycin, methicilin, piperacillin, pefloxacin, novobiocin, cefepime, trimethoprim, netilmicin, and aztreonam. Conclusion: This studys results uncover the occurrence and antibiotic resistance pattern of E. coli in the study areas turkeys. [J Adv Vet Anim Res 2021; 8(1.000): 64-69]

Campylobacter species are basic bacterial microbes that cause gastro enteritis in people, both in most industrialized and most creating countries. Campylobacter has been recuperated from chicken corpses, poultry meat parts and supplies in preparing plants worldwide. The regularly announced pathogenic species is C. jejuni representing over 90% of the cases, trailed by C. coli speaking to 7% of the diseases, with the remainder of cases being chiefly C. lari and C. fetus.The objective of this investigation is to decide the prevalence of Campylobacter spp. in some poultry items by utilizing both traditional and recent strategies. One hundred and twenty chicken samples were gathered from different grocery stores at Menofia governorate (25g of every one)taken of chicken breast, thigh, liver and gizzard are taken without any pollution or careless. Most examples were debased with Campylobacter spp. Chicken liver indicated the most elevated defilement item (56.67%) trailed by gizzard(53.33%), thigh (30%) and breast (23.33%) gradually.The level of antimicrobial resistance rate of C.jejuni to cephalothin, oxytetracycline, erythromycin, nalidixic acid, ampicillin ,gentamicin,streptomycin,ciprofloxacin,neomycin,chloramphenicol were 22.2%,33.3%,94.5%,77.8 % ,11.1% ,5.5%,100%,44.4%,61.5and44.4% individually.

In order to assess the prevalence of Salmonella contaminations in the city of Garoua, this study investigated the research and serotyping of Salmonella strains within the traditional chicken industry at the poultry slaughterhouse of the central market of Garoua in Bénoué, Northern Region of Cameroon. Still very present throughout Cameroon, this structure can represent a source of contamination as well as a zoonotic hazard. For this purpose, the study was carried out on 400 chicken carcasses and analyses were performed on cloacal swabs, by bacteriological culture and confirmed by biochemical analyses and PCR to detect the invA gene specific to Salmonella sp. Thus, 05 strains of Salmonella were isolated, a contamination prevalence of 1.3% observed. Serotyping of the isolates resulted in the identification of five different serovars, including Hadar, Idikan, Mbandaka, Infantis and Anatum (n=1, 20% each). These serotypes developed resistance to tetracycline, amikacin, nalidixic acid, Kanamycin and cephalothin. Antibiotics available on the market at low cost and used without precise diagnosis and in insufficient or overdosed doses in the veterinary environment, both in food and for the treatment of bacterial infections. This study has an important impact because it showed for the first time the presence of Salmonella in the traditional chicken industry in the Northern Region of Cameroon. The project also highlighted the role that this type of structure can have in the maintenance and circulation of pathogens within animal and human populations. Indeed, in view of the weak biosecurity measures applied, family farming systems represent an important risk factor for the spread of Salmonella in both animals and humans, and could be resistant to certain antibiotics.

The canary (Serinus canaria) is appreciated for its beautiful song, colors, and docile temperament and drives a lucrative business. However, diseases caused by avian pathogenic Escherichia coli (APEC) compromise the health of canaries, and the inadequate antimicrobial treatment can lead to the emergence of resistant strains. This study aimed to characterize 21 isolates of E. coli obtained from canaries infected with colibacillosis during an outbreak in northern Paraná State, Brazil. APEC and diarrheagenic E. coli (DEC) virulence genes were screened for by polymerase chain reaction (PCR). All isolates were positive for the hlyF, iss, and ompT genes, which are characteristic of APEC. The iroN gene was found in 95.2% of isolates, and none had the iutA gene. The ipaH gene, characteristic of enteroinvasive E. coli (EIEC), was found in 71.4% of isolates, all belonging to the phylogenetic group B1. High genetic similarity (>95%) was found using enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). The isolates belonged to serotypes O117:H4 (71.4%) and O1:H20 (23.8%). This is the first report of a clonal colibacillosis outbreak in canaries caused by APEC. All isolates were resistant to ampicillin, nalidixic acid, ciprofloxacin, enrofloxacin, norfloxacin, and tetracycline. The high rate of multidrug resistance in our study shows the importance of avoiding the inadequate antibiotic treatment. We suggest that further studies should be conducted to contribute to the understanding of colibacillosis in canaries since the health of animals is linked to human and environmental health, as defined by the concept of One Health.

This research aimed to evaluate Staphylococcus aureus contamination from milk and its derivatives available in local dairy sale centers around the Kabul University located in Kabul city. Samples were included caw`s raw and pasteurized milk, cheese, ice cream, yogurt, custard, and dough (native product). The mentioned products were collected and then using the conventional method was tested in the laboratory. 70 samples were tested, from tested only 18 samples were presented Staphylococcus aureus, as these isolates had a positive reaction for coagulase. The disk diffusion method plus 8 antibiotics which are commonly used in the Veterinary section were used for antimicrobial sensitivity reaction. Staphylococcus isolated samples showed resistance against more than 3 antibiotics, maximum resistance was to Nalidixic acid (50%) followed by Ciprofloxacin (44.44%), Norfloxacin (27.77%), Erythromycin and Methicillin (27.77%), and Tetracycline (22.22%). All the isolates susceptibility was high to Polymaxine and resistant to Ampicillin (100%). As we found in our study the biological quality of tested samples sold around Kabul University were notsatisfactory as well as resistance against the mentioned antibiotics except two antibiotics. The contaminated products could be a potential risk to humans .

In the United States, farm-raised shrimp accounts for ~ 80% of the market share. Farmed shrimp are cultivated as monoculture and are susceptible to infections. The aquaculture industry is dependent on the application of antibiotics for disease prevention, resulting in the selection of antibiotic-resistant bacteria. We aimed to characterize the prevalence of antibiotic-resistant bacteria and gut microbiome communities in commercially available shrimp. Thirty-one raw and cooked shrimp samples were purchased from supermarkets in Florida and Georgia (U.S.) between March–September 2019. The samples were processed for the isolation of antibiotic-resistant bacteria, and isolates were characterized using an array of molecular and antibiotic susceptibility tests. Aerobic plate counts of the cooked samples (n = 13) varied from

Generally, treatment of urinary tract infection (UTI) in children is a difficult task, due to development of high resistance against antibiotics. The object of this study is to investigate the greatest causative microorganisms, their susceptibility and resistance to antibiotics in children suffering from UTI in Baghdad. A total of 810 urine samples were collected from suspected cases of UTI in children patients of ages (1 day to 12 years) of both sexes. Urine specimens were examined by urinalysis and cultured for isolation of microbial agents. In this study, Bacterial growth was obtained in 202 samples (24.39%) out of 810 urine samples. Various pathogenic organisms were isolated, which represented by A) Gram-Negative bacilli include Escherichia coli (41.58%), Enterobacter spp. (13.68%), Proteus Mirabilis (12.78%), Acinetobacter spp. (4.45%), Providencia spp. (4.45%), Pseudomonas aeruginosa (3.46), Klebsiella pneumoniae (2.47%), Citrobacter spp . (0.49%), Salmonella Spp. (0.49%), B) Gram- Positive cocci: Staphylococcus aureus (11.38%), Enterococcus faecalis (1.98%) and S treptococcus agalactiae (1.48%) C) Candida albicans (0.9%).). According to antibiotic susceptibility test, mostly the isolates were resistant to Nalidixic acid (67.05%), cefotaxime (59.40%) and cefepime (50.49%). Mostly Gram-Negative bacilli were responsible for UTI, and maximum recurrent isolated bacteria were Escherichia coli . The isolated bacteria were found to be sensitive to Imipenem, Amikacin, and ciprofloxacin. Therefore, the selection of antibiotic therapy in UTI should depend on the native sensitivity form of the infecting organism.

Salmonellosis in poultry is an important disease that seriously impedes the development of the poultry industry. The increased resistance to antimicrobials against Salmonella has been a major public health concern worldwide. We conducted a study from January to June 2016 in and around the Rajshahi district of Bangladesh on the commercial chicken to isolate, identify and characterize poultry‐specific Salmonella, to assess the potential risk factors and to determine the antimicrobial resistance pattern of the isolates. The overall prevalence of Salmonella enterica was 41% (49/120) [95% CI: 31.95%–50.17%] with 41.7% in broiler chicken (25/60) [95% CI: 29.06%–55.12%] and 40% in layer chicken (24/60, 40%) [95% CI: 27.56%–53.46%]. Samples collected from Rajshahi city (OR = 1.37, 95% CI: 0.50–3.73) and Puthia Upazila (OR = 1.51, 95% CI: 0.56–4.12) were more likely to be positive for Salmonella than Charghat Upazila. Salmonella detection was 1.3 times higher in chicken, providing loose feed than those provided ready feed. All the isolates fermented dextrose, maltose and mannitol with the production of acid and gas, but did not ferment sucrose and lactose. The isolates showed catalase, MR, citrate utilization test and TSI agar test positive, but indole and V‐P tests negative. Salmonella isolates were sensitive to ciprofloxacin (90%), gentamycin (80%), amoxicillin (75%), streptomycin (70%), ampicillin (45%) and sulfamethoxazole‐trimethoprim (45%), whereas highly resistant to penicillin (100%) and nalidixic acid (100%) followed by sulfamethoxazole‐trimethoprim (55%), ampicillin (40%) and amoxicillin (25%). Salmonella enterica is endemic in commercial chicken production in Bangladesh with high prevalence. A considerable proportion of Salmonella isolates was found to be resistant to the majority of the common antimicrobial drugs. A good biosecurity system could be effective for the reduction of Salmonella. It is necessary to obtain universal commitments to establish prudent antibiotic use policies., This study reported the prevalence and antimicrobial susceptibility profiles of Salmonella isolated from chickens in Rajshahi, Bangladesh. This study showed the endemicity of Salmonella in commercial chicken production in Bangladesh with their resistant to the majority of the common antimicrobial drugs. Salmonella detection was 1.3 times higher in chicken, providing loose feed than those provided ready feed.

Klebsiella pneumoniae is an important pathogen causing hospital‐acquired infections in human beings. Samples from suspected patients of K pneumoniae associated with respiratory and urinary tract infections were collected at Bolan Medical Complex, Quetta, Balochistan. Clinical samples (n = 107) of urine and sputum were collected and processed for K pneumoniae isolation using selective culture media. Initially, 30 of 107 isolates resembling Klebsiella spp. were processed for biochemical profiling and molecular detection using gyrase A (gyrA) gene for conformation. The K pneumoniae isolates were analysed for the presence of drug resistance and virulence genes in their genomes. The 21 of 107 (19.6%) isolates were finally confirmed as K pneumoniae pathogens. An antibiogram study conducted against 17 different antibiotics showed that a majority of the isolates are multidrug resistant. All the isolates (100%) were resistant to amoxicillin, cefixime, amoxicillin‐clavulanic acid, cefotaxime, and ceftriaxone followed by tetracycline (95.2%), ciprofloxacin and gentamicin (76.2%), sulphamethoxazol (66.7%), nalidixic acid (61.9%), norfloxacine (42.9%), piperacillin‐tazobactam (23.8%), cefoperazone‐sulbactam (19%), and cefotaxime‐clavulanic acid (33.3%), whereas all the isolates showed sensitivity to amikacin, chloramphenicol, and imipenem. The presence of tetracycline, sulphamethoxazol‐resistant genes, and extended‐spectrum beta‐lactamase was reconfirmed using different specific genes. The presence of virulence genes fimH1 and EntB responsible for adherence and enterobactin production was confirmed in the isolates. The high virulence and drug resistance potential of these Klebsiella isolates are of high public health concern. Multidrug resistance and virulence potential in K. pneumoniae are converting these nosocomial pathogens into superbugs and making its management harder.

In this work, multi-walled carbon nanotubes were applied as sorbent for extraction, followed by back-extraction and HPLC/UV determination of Nalidixic acid in aqueous solutions. The effects of some parameters such as pH, flow velocity, sorbent amount, and ionic strength were investigated. A little amount of sorbent (5.0 mg) was chosen as its optimum amount which this sorbent was reusable for almost five cycles of adsorption/desorption processes. A preconcentration factor of 500 was obtained. Linear range was 0.19–23.2 mg L−1 (R2 = 0.9979). The limit of detection and RSD for the suggested method were 0.02 mg L−1 and 2.2%, respectively. To assess the method performance for real samples, Nalidixic acid was determined in human blood serum and tablet samples. Advantages of the suggested method for Nalidixic acid extraction and preconcentration are low cost, being less time consuming, simplicity, no usage of organic solvents, and high preconcentration factor and efficiency.