uency of various organisms in both genders and in various age subgroups is different but statistically non-significant (p = 0.286) and (p = 0.253) respectively.
Our results displayed that all 152 isolates were highly resistant to majority of standard antibiotics. Overall, the highest resistance of isolates was shown by ampicillin. Whereas, the antibiotics which has shown least resistance are imipenem and amikacin as given in Table 2.
As shown in Figure 2 and Table 3, the sensitivity pattern of various antibiotics analyzed for individual organism showed that E. coli was resistant to majority of commonly used antibiotics, highest resistance was shown for ampicillin (93.5%), followed by ceftazidime (80%) and cefotaxime (80%), whereas most sensitive antibiotic for E. coli were found to be amikacin (97.8%) and imipenem (97.8%). For klebsiella most resistant antibiotics was ampicillin (92.9%) and then Amoxicillin-clavulanic acid (82.6%),while most effective antibiotics were imipenem (96.4%), amikacin (92.9%) and gentamycin (92.9%). While Salmonella was isolated only in 4 samples and maximum sensitivity, (100%) was observed for amikacin, gentamycin, ciprofloxacin and levofloxacin.
Annually, 1.5 million children lose their lives on account of diarrhea out of the total 10 million deaths in the pediatric age group and it is also regarded as one of the leading causes of morbidity and mortality in children less than 5 years of age throughout the world .
Table 1. Basic demographic features of children under 5 years of age with diarrhea.
*P value significance; level: (P < 0.05).
Table 2. Over all antibiotics sensitivity and resistance patterns of bacterial specimens isolated from the stool samples of children with diarrhea, total N = 152.
Z.O.I = Zone of inhibition (diameter in mm), R = Resistance, S = Sensitive.
Table 3. Sensitivity pattern of drug with organisms (n = 152).
Figure 1. Distribution of organisms.
Figure 2. Average Zone of inhibitions of different antibiotics with organisms. AMK; Amikacin, AMC; Amoxicillin-clavulanic acid, CN; Gentamycin, CXM; Cefuroxime, CAZ; Ceftazidime, ATM; Aztreonam, AMP; ampicillin, CTX; cefotaxime, CIP; Ciprofloxacin, NA; Nalidixic acid, LEV; Levofloxacin, CRO; Ceftriaxone, IMP; Imipenem, SXT; Trimethoprim-Sulfamethoxazole, CEF/SUL; Cefoperazone/Sulbactam, PIP/TAZO; Piperacillin/Tazobactam [*shows significant P values].
Pakistan is one of the fifteen developing countries, which has shown the highest burden of diarrheal diseases . Our study conducted at pediatric unit of a tertiary care hospital of Karachi displayed that most (80%) of the cases of pediatric diarrhea were presented from low socioeconomic class. According to our study, 152 (46.77%) stool samples were found to be positive for bacterial pathogens out of 325 total samples as shown in table I, which revealed that infectious diarrhea is highly prevalent in our clinical set up. One of the previous studies conducted from the year 2002 till 2006 on children <5 years of age living in squatter settlements of central Karachi, displayed that the burden of infectious diarrhea varied from 29% to 37% . In 2016, WHO statistics of Pakistan stated the prevalence of diarrhea in children is 23% . This is clearly indicating that disease burden of diarrhea is rising in our population with time. Presumably the reason behind rising pattern and higher burden of diarrheal disease among pediatric age group in our country is that the major chunk of our study population comes from the low socioeconomic areas which are directly linked to poor quality of drinking water and hygiene especially hand washing, improper disposal of waste material, lack of health education of mothers, immunization and nutritional status not maintained according to the age. This is quite evident from a report published in 2017 in the most leading and widely read English newspaper Dawn, which highlighted that Pakistan is the seventh worst country in terms of access to basic sanitation, as its 42 percent of the population remains without access to basic sanitation . On the basis of National Nutritional Survey conducted in different parts of the world the frequency of diarrhea in children less than 5 years of age was found to be variable, ranging from 22.3% in Ethiopia, 22.1% in Iraq, 21.3% in Egypt and 12% in Tanzania. In 2010, the study performed in Fatemieh children hospital, Central Iran, 514 (57.6%) children were diagnosed with infectious gastroenteritis .
According to our results more bacterial isolates were obtained from stool samples of male children i.e. 57% as compared to female children in which 43%, of samples were positive (Table 1) but this difference was non-significant (p = 0.286) as shown in table I. Whereas, the study published in the journal of Global Health Action in 2014, revealed that there was no gender predominance related to the frequency of diarrhea among children less than 5 years of age . Another study conducted in central Iran in 2010, also showed insignificant difference in the frequency of infectious diarrhea between male and female children (p = 0.22) .
In our study, E. coli was the most common pathogen isolated in 92 (60 %) stool samples out of the total 152, followed by the second common organism Klebsiella 56 (37%) and then Salmonella 4 (3%) as shown in Figure 1. E. coli is the facultative anaerobic gram negative bacillus which belongs to the family of Enterobacteriaceae. It is transmitted through fecal-oral route by using contaminated water and food. It was also detected in the milk given to the infants and young children through feeding bottles which were mishandled by the uneducated mothers especially seen in the children coming from low socioeconomic background . Similarly, E. coli was detected to be the frequent cause of acute infectious diarrhea in the developing countries, Sudan and India . On the contrary recent studies conducted in Turkey and Spain, displayed the highest number of Campylobacter and Salmonella species isolated from stool samples of children having diarrhea . Likewise, in the region of South America, Ecuador, Shigella species and Campylobacter jejuni were found to be prevalent, whereas in China, Shigella species were found to be the most common agents for pediatric infectious diarrhea .
Our current study showed that the majority of cases of E. coli and klebsiella were found in 13 - 24 months of age, subsequently the number of cases decreased in 49 - 60 and 37 - 48 months of age respectively as shown in table I. Similar results were presented by Amir Saeed et al. in 2015, which stated, E. coli is the most common causative agent of diarrhea in children under five year of age in Khartoum, Sudan . Another study published in Tanzania 2014, the epidemics of diarrhea is significantly higher in the age groups of 18 - 23 months .
Various microorganisms are resistant to multiple antibiotics and hence named as multidrug resistant organisms. In our study the organism which showed the resistance to majority (more than 60%) of the antibiotics is E. coli. The study published in the American Journal of Tropical Medicine and Hygiene stated that Escherichia coli (E. coli) is the most frequently occurring organism in children under 5 years of age and is almost entirely resistant to many antibiotics . As mentioned in Figure 2 and Table 3, our current study revealed that E. coli is resistant to majority of the commonly prescribed antibiotics, appropriate for pediatric age group, including among penicillins (amoxiclav, ampicillin, amoxicillin), cephalosporins (cefotaxime, ceftriaxone cefuroxime, ceftazidime), while gentamicin, aztreonam, and trimethoprim-sulfmethoxazole were also resistant. Likewise, Klebsiella has also showed resistance against commonly prescribed antibiotics, amoxicillin, cefuroxime, cefotaxime, ceftriaxone, ampicillin and trimethoprim-sulfmethoxazole. Although in our study, Salmonella was isolated in 4 samples only out of the total 152 but like other two organisms Salmonella has also shown higher resistance for cephalosporins (cefuroxime, ceftriaxone) and trimethoprim-sulfmethoxazole. Surprisingly in comparison to both of the organisms, Salmonella has showed higher resistance to imipenem as well, which is not prescribed routinely and is reserved for infections due to resistant Pseudomonas Aeruginosa . Interestingly the intra group comparison of sensitivity of E. coli, Klebsiella and Salmonella displayed that among all antibiotics, the ZOIs of ceftazidime, aztreonam, ceftriaxone, nalidixic acid, imipenem and cefoperazone/sulbactam were highly significant for all the three organisms as shown in Figure 2, probably showing the clear difference between ZOIs of sensitive and resistant antibiotics mentioned above for all of the three organisms. Similarly, a recent study published in Feb. 2018, Italy, precisely exposed E. coli strains resistant to ampicillin, cotrimoxazole, chloramphenicol, ceftriaxone, and ceftazidime. In the same study, Klebsiella species were found resistant to ampicillin, cefotaxime, cefuroxime, co-amoxiclav, mezlocillin, chloramphenicol, gentamicin, and ceftazidime , whereas Salmonella strains were resistant to ampicillin, cephalotin, ceftriaxone, gentamicin, amikacin, trimethoprim-sulfamethoxazole, chloramphenicol, and tetracycline . Despite that Italy is among developed countries and our country, Pakistan is a developing country but the scenario of antibiotics resistance is same in both of the countries, possibly this is due to empirical and extensive use of antibiotics in clinical set-ups of both countries. Our results were also parallel to studies reported in other countries like China, which also approximately demonstrates the comparative outcomes .
In our study most sensitive antibiotic for E. coli and Klebsiella were shown to be aminoglycosides (amikacin and gentamycin) as well as imipenem, while Salmonella showed highest sensitivity (100%) to both aminoglycosides and fluoroquinolones (ciprofloxacin and levofloxacin) but was resistant to imipenem (50%) as shown in Figure 2 and Table 3. However, the study conducted in India 2016, showed the highest sensitive (100%) antibiotics for E. coli and Klebsiella are ciprofloxacin, norfloxacin and gentamicin . Whereas, the data as observed in Ethiopia 2017 reveals, Salmonella is highly sensitive to ceftriaxone and norfloxacin but resistant to amoxicillin .
In the light of above discussion it is evident that currently majority of commonly prescribed antibiotics, suitable for pediatric use in the treatment of bacterial diarrhea have been resistant. The reason is that globally the empirical use of antibiotics for different clinical situations as well as for all cases of pediatric diarrhea has been increased. Furthermore in our country, over-the-counter availability of various antibiotics has led people to self-medications. Subsequently this has increased resistance of highly useful antibiotics in our population, hence limited antibiotics are left for the treatment of serious infections in pediatric age group as majority of the sensitive drugs, such as aminoglycosides, fluoroquinolones and imipenem cannot be used in children due to systemic toxic effects.
Infectious diarrhea is highly prevalent among children of less than 5 years of age, affecting more commonly male children in our clinical setup. E. coli is responsible for majority of the cases and was found to be highly resistant to many of the standard antibiotics used currently for the treatment of infectious diarrhea in children. Although in comparison, our study displayed that imipenem, fluoroquinolones and gentamycin have better sensitivity profiles but owing to their limited use in pediatric age group, could not be recommended in pediatric diarrhea leaving less treatment options for this age group. This situation is quite grave and can lead to even greater number of morbidity and mortality in this age group on account of diarrhea only.
In order to minimize the resistance, injudicious use of antibiotics should be stopped as well as should not be prescribed empirically for the treatment of all cases of pediatric diarrhea. The decision of giving antibiotics should be based on patient’s detailed history, clinical examination and according to the culture and sensitivity reports. Subsequently, this will help in reducing the cost and economic burden due to the overuse of antibiotics on our underprivileged population and will also improve the overall health of children.
The increasing resistance of antibiotics in children requires serious measures and implementations at national and international levels which emphasizes the need to explore other simple, supportive, effective and alternative treatment for resolving the burden of diarrheal diseases in children less than 5 years of age. Furthermore, the use of some antibiotics should be restricted to serious systemic and life-threatening infections in pediatric age group.