Amoxicillin (AMO) and amikacin (AMK) are broad-spectrum antibiotics that are most preferably given post-delivery (normal and cesarian) in the maternity hospitals located in Sagar city (Madhya Pradesh), India. Both the antibiotics make their way through sewage/drainage systems into the environment in the form of metabolized and unmetabolized compounds. Growing concern about the contamination of wastewater by antibiotics requires fast, sensitive and eco-friendly techniques. Therefore a simple, rapid and environmental friendly chromatographic method has been developed for simultaneous determination of AMO and AMK in maternity hospital wastewater samples. A micellar liquid chromatographic (MLC) method was developed with a C₁₈ column (250 mm × 4.6 mm), sodium dodecyl sulphate (SDS; 0.15 M), 1-butanol (7%) as a modifier, pH 5 and photo diode detector (PDA) at 270 nm and 256 nm for AMO and AMK respectively. The method was fast with analysis time below 9 min. In the present MLC method, linearities (r > 0.998), limits of quantification in the range of 0.02–0.04 μg/mL, repeatabilities, and intermediate precision below 4.9% were adequate for the quantification of AMO and AMK. The proposed method can be utilized to detect and quantify both the antibiotics in various samples by hospitals, pharmaceutical companies, pollution control board, municipal corporations, etc.

Antibiotic resistance is known to impact treatment efficiency of Plesiomonas infections negatively with fatal outcomes. This study investigated antibiogram fingerprint of P. shigelloides (n = 182) isolated from three South Africa rivers using the disc diffusion technique. Environmental pollution and analogous health risk (given infections) that could associate with the freshwaters and empirical treatment of Plesiomonas were assessed using Antibiotic Resistance Index (ARI) and Multiple Antibiotic Resistance Indices (MARI), respectively. Thirteen EUCAST recommended (ERAs) and eleven non-recommended antibiotics (NAs) used as first line agents in the treatment of gastroenteritis and extraintestinal infections were tested. Resistance against ERAs decreased from cefoxitin (37.91%), cefuroxime (35.17%), cefepime (31.87%), ceftriaxone (29.67%), ciprofloxacin (18.13%), trimethoprim-sulfamethoxazole (10.44%), piperacillin/tazobactam (8.79%), ertapenem (4.95%), norfloxacin (4.40%), levofloxacin (2.75%), meropenem (1.10%) to imipenem (0.55%). The isolates had higher resistance (≥36.07%) against NAs but were susceptible to amikacin (67.58%), gentamycin (73.08%), and tetracycline (80.77%). MARI of the isolates were significantly different between ERAs and NAs (P-value < 0.05) and had an average of 0.17 ± 0.18 and 0.45 ± 0.13, respectively. About 33.87% and 95.63% of the isolates had MARI value from 0.23 to 0.62 and 0.27–0.82 to ERAs and NAs, respectively. Also, ERAs-based and NAs-based ARI across sampling units showed significantly different (P-value < 0.05) means of 0.18 ± 0.09 and 0.46 ± 0.05, respectively. MARI attributed low risk of empirical treatment to recommended antibiotics but higher risk to non-recommended antibiotics. Model estimated successful and unsuccessful empirical treatment of infections risks due to resistance in the isolates using recommended antibiotics as 65.93% and 34.07%, respectively; 1.65% and 98.35% in the case of non-recommended antibiotics, respectively. ARI based on recommended antibiotics identified potential environmental pollutions in a number of sites. Resistance in freshwater P. shigelloides especially against cephalosporin, quinolones and fluoroquinolones is distressing and might suggests high pollution of the freshwaters in the Eastern Cape Province.

The prevalence of antibiotic resistance and the implicated mechanisms of resistance were evaluated in Enterococcus spp. and Escherichia coli, isolated from a total of 250 faecal samples of echinoderms collected from Azorean waters (Portugal). A total of 144 enterococci (120 Enterococcus faecium, 14 E. hirae, 8 E. faecalis, 2 E. gallinarum) and 10 E. coli were recovered. High percentages of resistance in enterococci were found for erythromycin, ampicillin, tetracyclin and ciprofloxacin. The erm(A) or erm(B), tet(M) and/or tet(L), vat(D), aac(6′)-aph(2″) and aph(3′)-IIIa genes were found in isolates resistant to erythromycin, tetracycline, quinupristin/dalfopristin, high-level gentamicin and high-level kanamycin, respectively. Resistance in E. coli isolates was detected for streptomycin, amikacin, tetracycline and tobramycin. The aadA gene was found in streptomycin-resistant isolates and tet(A)+tet(B) genes in tetracycline-resistant isolates. The data recovered are essential to improve knowledge about the dissemination of resistant strains through marine ecosystems and the possible implications involved in transferring these resistances either to other animals or to humans.

The quality of water resources can be altered by human activities carried out in watersheds. These changes can lead to the occurrence of antibiotic-resistant bacteria and compromise public health. The aim of the present study was to evaluate the presence and concentration of total coliforms and Escherichia coli in the water at the Ecological Park Tietê in São Paulo, the antibiotics resistance of isolated E. coli, and the interaction between season, collection points, and water quality variables. Sample localities were georeferenced and identified as P1—drinking water from the distribution system (23°29′33.46″S, 46°31′16.12″O); P2—main lagoon of the park (23°29′37.59″S, 46°31′28.22″O); and P3—connection between the main lagoon and the Tietê River (23°29′14.66″S, 46°31′26.57″O). Physical–chemical and microbiological variables were measured. Data were subjected to analysis of variance. The isolated effect or the interaction between season, collection points, and variables had the means compared to each other by the Scott-Knott test. The microbiological analysis was performed by inoculating the samples in 3 M™ Petrifilm™ E. coli/Coliform Count Plates (containing agar medium with Violet Red Bile nutrients), incubated at 37 °C for 48 h and the E. coli isolated had their antibiotic resistance profile tested by the disk diffusion technique using Mueller–Hinton agar. Total coliforms and E. coli were not identified at P1. Total coliforms were identified in 64% of the samples and E. coli was identified in 36% of the samples. The microbial contamination of the surface waters of the park presents seasonal variation with higher concentrations of E. coli in the hottest and rainiest seasons (spring and summer). The isolated E. coli showed greater resistance to erythromycin (82%) and amoxicillin (55%) in P2 and to erythromycin (82%) and amoxicillin (27%) in P3, with the presence of multiresistant isolates at both points. No strain showed resistance to amikacin. The high rate of resistance of E. coli to the antibiotics frequently used in human and veterinary medicine demonstrates that the contribution of these substances in aquatic ecosystems over the years has exerted a selection pressure on microorganisms, assisting the appearance and spread of resistant bacteria, changing the environmental biota, and turning these locations in possible reservoirs of antibiotic resistance.

Vibrio species, widely distributed in water environments, has emerged as a prominent cause of water and food-related disease outbreaks posing significant risk to human and animal health worldwide. About 40% of presumptive isolates recovered from four selected rivers in Southwest Nigeria and, established as Vibrio species genus through polymerase chain reaction techniques., were subjected to antibiotic susceptibility testing against a panel of 18 commonly used antibiotics. The relative prevalence of key Vibrio species (V. parahaemolyticus, V. vulnificus, V. mimicus, V. harveyi, and V. cholerae) was in the order 17%, 13.3%, 4.4%, 2.2%, and 2.2% respectively. Antibiotic resistance by all Vibrio species was mostly observed against doxycycline (71–89%), erythromycin (86–100%), tetracycline (71–89%), rifampicin (86–100%), and sulfamethoxazole (87–100%), though susceptibility to meropenem (86–100%), cephalothin (60–100%), norfloxacin (93–100%), ciprofloxacin (88–100%), amikacin (64–100%), gentamicin (57–74%), and trimethoprim/sulfamethoxazole (57–81%) was equally observed in all species. Vibrio mimicus expressed highest resistance against streptomycin and chloramphenicol (64%), while V. vulnificus (52%) and V. cholerae (57%) had the highest resistance against cephalothin. High resistance against ampicillin (57%) and amoxicillin (50%) was exhibited by V. cholerae and V. mimicus respectively. Indexes of multiple antibiotic resistances (MARI) among Vibrio species ranged between 0.11 and 0.72 with the highest MAR index of 0.72 observed in one isolate of V. vulnificus. This study reveals high prevalence of Vibrio species in the selected rivers as well as elevated resistance against some first-line antibiotics, which suggests possible inappropriate antimicrobial usage around study communities. We conclude that the freshwater resources investigated are unfit for domestic, industrial, and recreational uses without treatment prior to use and are potential reservoirs of antibiotic-resistant Vibrio species in this environment.

Sichuan, located in the upper reaches of the Yangtze River, is the gathering place of many rivers and plays an important role in sturgeon aquaculture and wild sturgeon protection in China, where it suffered the severe influence of Streptococcus iniae infection in sturgeon. However, the annual thousands of tons of antibiotic usage in Sichuan may accumulate in water and cause obstacles to the prevention of S. iniae infection. In contrast, the regional antibiotic resistance characteristics have been rarely unknown. Seventeen S. iniae strains were collected from the major sturgeon culture areas in Sichuan, and the genotyping and the distribution of antibiotic resistance profiles (ARPs) and genes (ARGs) of S. iniae were established in this study. The results showed that the isolates could be divided into four subtypes by pulsed-field gel electrophoresis analysis. Besides, most isolates showed multiple resistance to the antibiotic such as amikacin, neomycin, enrofloxacin, lincomycin, and sulfamethoxazole. Also, sturgeon-derived S. iniae has a relatively low similarity with other fish-derived S. iniae in the world but high similarity with three animal-derived pathogens from Sichuan in previous studies. Moreover, a total of 37 ARGs were detected positively based on 95 ARGs detection, in which aac(6')-Ib(aka aacA4)-01, aac(6')-Ib(aka aacA4)-02, aadA1, floR, blaTEM, sulA/folP-03, and tetA-02 were most prevalent. Our study indicated that the ARGs of sturgeon-derived S. iniae were significantly enhanced compared with the ATCC29178 strains and have a risk of accessing more ARGs from other bacteria in water in Sichuan. This study claimed that sturgeon has a potential risk in the prevention and control of Streptococcosis in Sichuan, the upper reaches of Yangtze River, based on the antibiotic resistance analysis of S. iniae, and it may also increase the risk of highly resistant S. iniae transmission into the middle and lower reaches.

Ventilator-associated pneumonia (VAP) is the most frequent infection in intensive care units (ICU). It is associated with high rates of long morbidity and mortality. Management of a case of VAP is often said to add $40,000 to hospital costs USA. All these data directed our interest to study the etiology, risk factors, and antibiotic susceptibility patterns of VAP in ICU of Tanta University Hospital. This study included 36 cases of VAP. Endotracheal aspirates were obtained from all cases and microbiologically analyzed. Samples were collected over 1 year. Forty-two strains were isolated from 28 cases, while eight cases showed no bacterial growth. The most frequent organism was Staphylococcus aureus (30.95%), followed by Acinetobacter baumannii and Pseudomonas aeruginosa (21.43% for each), and the least common was Staphylococcus epidermidis (2.38%). Multi-drug resistance was detected in (50%) of the isolated bacteria in this study. Imipenem, amikacin, linezolid, vancomycin, and levofloxacin are recommended to be the most effective drugs in management of VAP. VAP is a serious problem in ICU carrying many risks for the patient live. Regimens of empirical treatment should take in consideration the update in the bacterial etiology and antibiotic susceptibility patterns of VAP.

We evaluated the antibiogram profile of Escherichia coli (n = 300) isolated from selected rivers in Osun State, Nigeria. The identities of the E. coli isolates were confirmed by polymerase chain reaction (PCR) technique. Susceptibility of the isolates to 20 antibiotics conventionally used in clinical cases was assessed in vitro by the standardized agar disc-diffusion method. All the isolates were susceptible to imipenem, meropenem, amikacin and gatilofloxacin. The isolates were variously susceptible to the other antibiotics as follows: ciprofloxacin (96 %), kanamycin (95 %), neomycin (92 %), streptomycin (84 %), chloramphenicol (73 %), nalidixic acid (66 %), nitrofurantoin (64 %), gentamycin (63 %), doxycycline (58 %), cefepime (57 %), tetracycline (49 %) and cephalothin (42 %). The multiple antibiotic resistance indexing ranged from 0.50 to 0.80 for all the sampling locations and exceeded the threshold value of 0.2, suggesting the origin of the isolates to be of high antimicrobial usage. Our findings signify an increase in the incidence of antimicrobial resistance of E. coli towards conventionally used antibiotics necessitating proper surveillance programmes towards the monitoring of antimicrobial resistance determinants in water bodies.

The current study was performed to investigate the nephroprotective efficacy of Spirulina platensis (SP) and the possible benefits of combining SP and ascorbic acid (AA) in protecting against amikacin (AMK)-induced nephrotoxicity in rabbits. Forty-two male New Zealand rabbits were allocated to seven equal groups, receiving (I) normal saline as negative controls, (II) oral SP (500 mg/kg body weight), (III) oral AA (20 mg/kg bw), (IV) intramuscular AMK injection (100 mg/kg bw), (V) AMK plus SP, (VI) AMK plus AA, or (VII) AMK plus SP and AA at the aforementioned doses. The treatments were given once/day for 7 days. Data analysis showed that in comparison to the control group, AMK-intoxicated rabbits showed significant increases (p ≤ 0.05) in serum concentrations of creatinine, uric acid, and urea, as well as renal tissue concentrations of tumor necrosis factor-α [TNF-α], malondialdehyde [MDA], and nitric oxide [NO]. Moreover, significant (p ≤ 0.05) reductions in renal glutathione concentration, antioxidant enzymatic activities (catalase, glutathione peroxidase, and superoxide dismutase), and total antioxidant capacity were noted following AMK intoxication. Treatment by SP ameliorated most of the aforementioned AMK-induced alterations. Although treatment with AA significantly reduced the renal tissue MDA, NO, and TNF-α concentrations, it was not associated with significant ameliorations of AMK-induced changes in the serum concentrations of renal function markers or renal tissue antioxidant parameters. The nephroprotective effects of SP-AA combination were more potent than SP alone in several parameters. In conclusion, SP alone or in combination with AA minimized the nephrotoxic effects of AMK through their antioxidant and anti-inflammatory activities.