Escherichia coli is a Gram-negative bacteria that causes various diseases, including pneumonia, urinary tract infections, and diarrhoea. The present work is an effort to study antimicrobial resistance pattern in this bacteria. Clinical samples (6840) were collected from King Fahd Hospital in Madinah, Saudi Arabia and screened for E. coli strains. Of all positive samples obtained from different clinical sources, about 3% isolates represented E. coli and 71.6% of these were collected from clinical samples of male patients. E. coli isolates were recovered from sputum (20.58%), wound (55.88%), and catheters tips (9.31%) representing about 86% of all clinical specimens. Antimicrobial susceptibility pattern of the E. coli isolates to twelve different antimicrobials revealed that all the isolates (100%) were susceptible to imipenem, amikacin, and aztreonam. Cefoxitin, ceftazidime and ciprofloxacin showed a sensitivity of 98.7%. This was followed by gentamycin (98.6%), piperacillin (95.7%), cotrimoxazole (92.3%), cephalothin (91.4%), and Augmentin (91.1%). Ampicillin showed the least susceptibility of 87.5%. Hence, cotrimoxazole, Augmentin, and ampicillin should be prescribed with care in order to avoid increasing resistance patterns in E. coli. Results also demonstrate that frequency of E. coli infections was highest during summer and winter seasons representing about 30% each. Autumn season, which coincided with the season of pilgrimage, recorded about 22% of infections while spring season had the least recorded percentage with only 17% of infections. This study is therefore a step towards the generation of national data on the prevalence of antimicrobial resistance patterns of E. coli.

Methicillin-resistant Staphylococcus aureus (MRSA) strains are on the rise leading to severe morbidity and mortality in ICU patients worldwide including Saudi Arabia. In the present study, the prevalence, gender distribution and antimicrobial resistance pattern of this gram-positive nosocomial bacterial pathogen were explored. The strains were isolated from 6840 sampled patients at King Fahd Hospital, Madinah, KSA. Clinical sources were screened for MRSA strains during a period of 14 months and it was observed that MRSA represented only 5% of the total isolated positive samples. Exactly 237 MRSA strains were isolated from male patients and hence showed predominance over female samples, except in case of two sources (catheter tips and pus sample). Almost equal percentages of MRSA strains were recovered from wound swabs (124 strains) and sputum (120 strains) samples while 37 strains were recovered from nasal swabs. Collectively these three sources contributed majorly 84.7%. Antimicrobial sensitivity to conventional drugs was studied and the percentage resistance was in the following order: amoxicillin (99.5 %) ˃ daptomycin, (98.8 %) ˃ linezolid (98.0 %) ˃ clindamycin (91.3 %) ˃ erythromycin (90.8 %). ˃ cotrimoxazole (84.4 %) ˃ vancomycin (37.2 %). Vancomycin showed significant sensitivity of 62.8 % suggesting that this drug is a better option for effective treatment. After a high trend of MRSA infection (51%) during summer, a significant decrease (20.7%) was observed during autumn which coincides with the annual Hajj season when special infection control provisions are taken. After Hajj season is over, infections decrease further to 18.5% during winter and 9.8% in spring. The present study is significant in being a step towards generation of national data on the prevalence of antimicrobial resistance patterns of MRSA.

Pseudomonas spp. are the leading cause of nosocomial infections. Rise in multidrug resistance among clinical isolates limit therapeutic options and hence increase mortality rate. Clinical samples (6840) from a hospital in Madinah, Saudi Arabia were collected for a duration of 14 months to study the frequency, antimicrobial sensitivity pattern and seasonal variations of Pseudomonas isolates. Conventional biochemical tests were done to identify the probable organism and antibiotic susceptibility was performed by disc diffusion method and Phoenix automated microbiology 100 ID/AST system. Pseudomonas represented 6.5% of all positive samples of which 65% were from males. Majority of the organisms (85%) were isolated from sputum and wound swabs followed by catheter tips (6.4%) and throat aspirates (3.4%). From the remaining samples, less than 1% organisms were obtained. Assessment of antimicrobial susceptibility to 11 different antibiotics revealed that imipenem was the most effective with highest sensitivity of 99.5%, and low intermediate resistance of only 0.5%. This was followed by ciprofloxacin (97.5%), ceftazidime (96.3%), cefpiramide/amikacin (94.1%), aztreonam (93.2%), gentamycin (87.7%), ampicillin (83%), and cotrimoxazole (80.1%). The most resistant drugs included augmentin (25%), cotrimoxazole (19.9%), ampicillin (17%) and gentamycin (12.3%) while the least resistant were ciprofloxacin (1.5%) and imipenem (0%). Results recommend imipenem as a promising antibiotic against Pseudomonas infections. In case of resistance to imipenem, ciprofloxacin, ceftazidime, cefpiramide, amikacin, and aztreonam may be recommended. In acute cases, Pseudomonas infections may require combined antimicrobial therapy. Frequency of these infections was the lowest (17%) during spring. It was the highest (30%) during summers and winters but reduced to 22% during autumn maybe due to better hygiene during pilgrimage season.

Multidrug resistance, in rapidly spreading bacterial species, is a matter of concern in health care units. Samples (6840) collected from a Saudi hospital in Madinah, were screened for Acinetobacter spp. and studied for frequency, gender distribution, and seasonal variations besides antimicrobial resistance pattern. Acinetobacter strains represented 5.5% of the clinical isolates from different sources. Of these, 63% were recovered from male samples. The largest numbers of these organisms were isolated from sputum and wound swabs representing about 85% of the samples. Antimicrobial sensitivity pattern showed that colistin was the most effective drug since it inhibited 76% of the Acinetobacter isolates. The remaining drugs did not reveal sensitivity greater than 15%. Results suggest colistin to be a promising drug in the treatment of Acinetobacter infections. It was also observed that percentage of these infections was highest during summers representing 39.15%, followed by autumn (28.17%) and winters (26.48%), while spring season recorded the least percentage with only 6.2% of infections. The present study was an attempt to generate data on the prevalence of resistance pattern and management of Acinetobacter infections.

Klebsiella infection is often the leading cause of morbidity and mortality. Resistance pattern of antimicrobial susceptibility to commonly prescribed drugs were studied in Klebsiella isolates from a hospital in Madinah, Saudi Arabia. Clinical samples were collected from 6840 patients and screened for Klebsiella species over a period of 14 months. The strains were identified using microbiological and biochemical tests while the antibiotic susceptibility was performed by disk diffusion assay. Of all the positive samples isolated, only 275 samples were identified as Klebsiella species. Of these 66% were from males indicating that females are less vulnerable. Maximum isolates (66 to 70%) were collected from sputum and wound swabs of males. About 90% species were isolated from wound, sputum and catheter tips swabs. Antimicrobial sensitivity was studied using seventeen different antibiotics. Results revealed that antibiotic Imipenem has the highest sensitivity of 99.5% while Ampicillin revealed 100% resistance. The prescription of Imipenem antibiotic is recommended for the treatment of Klebsiella infections. In case of resistance to Imipenem, other antibiotics mainly Ceftazidime, Aztreonam, Ciprofloxacin, Cefoxitin and Piperacilline may be recommended. In acute cases, use of combined antimicrobial therapy may be required. Results also indicate that the intensity of Klebsiella infections is higher during summers (46.5%) than in winters (27.2%), while autumn (13.9%) and spring seasons (12.5%) showed the least recorded percentage. Our study will help in persistent and continuous monitoring of antimicrobial susceptibility and supplement the already available data on prevalence of antimicrobial resistance patterns of Klebsiella.